diff --git "a/raw_rss_feeds/https___arxiv_org_rss_physics.xml" "b/raw_rss_feeds/https___arxiv_org_rss_physics.xml" --- "a/raw_rss_feeds/https___arxiv_org_rss_physics.xml" +++ "b/raw_rss_feeds/https___arxiv_org_rss_physics.xml" @@ -7,2486 +7,2034 @@ http://www.rssboard.org/rss-specification en-us - Fri, 12 Dec 2025 05:00:11 +0000 + Fri, 19 Dec 2025 05:00:13 +0000 rss-help@arxiv.org - Fri, 12 Dec 2025 00:00:00 -0500 + Fri, 19 Dec 2025 00:00:00 -0500 Saturday Sunday - Lateral Deformation of Large-scale Coronal Mass Ejections during the Transition from Non-radial to Radial Propagation - https://arxiv.org/abs/2512.09937 - arXiv:2512.09937v1 Announce Type: new -Abstract: Many coronal mass ejections (CMEs) initially propagate non-radially, and then transition to radial propagation in the corona. This directional transition is a significant process that determines a CME's space weather effects but remains poorly understood. Based on multi-wavelength observations, we investigate the transition from non-radial to radial propagation in the low corona for two large-scale CMEs from the same active region on the solar limb. In the beginning, both CMEs move in a non-radial direction, beneath a system of overlying loops that are roughly parallel to the flux-rope axis. The CMEs laterally deform by bulging their upper flanks in the non-radial stage toward the higher corona, which results in the transition to a radial propagation direction approximately 25$^\circ$ away from the eruption site. After the directional transition, the non-radial-stage upper flank becomes the leading edge in the radial stage. Although the overlying loops do not strap over the flux rope, their strong magnetic tension force constrains the radial expansion of part of the CME during the transition by acting on the flux-rope legs. A major portion of the filament is displaced to the southern part of a CME in the radial stage, which implies the complexity of observational CME features. This study presents the first investigation of the lateral deformation during the transition of CMEs from non-radial to radial in the low corona, and makes an essential contribution to the complete CME evolution picture. - oai:arXiv.org:2512.09937v1 - physics.space-ph - astro-ph.SR - Fri, 12 Dec 2025 00:00:00 -0500 + A catalog of old globes in Spanish public collections + https://arxiv.org/abs/2512.15730 + arXiv:2512.15730v1 Announce Type: new +Abstract: This paper presents the first catalog of celestial and terrestrial globes, as well as armillary spheres and orreries, produced before 1900 and preserved in Spanish public institutions. Most globes have an English or French origin, predominantly from the late 18th or 19th centuries. We highlight a few outstanding examples, including an early metallic terrestrial globe, a mysterious blue celestial manuscript globe, the oldest preserved Spanish printed globe, and some interesting clockwork pieces. While Spain has not been a major producer of globes, it does preserve around two hundred historical globes in public collections, including several remarkable pieces. + oai:arXiv.org:2512.15730v1 + physics.hist-ph + Fri, 19 Dec 2025 00:00:00 -0500 new http://creativecommons.org/licenses/by/4.0/ - Huidong Hu (NSSC, CAS), Chong Chen (HUTB, China), Yiming Jiao (NSSC, CAS), Bei Zhu (Space Eng. U., China), Rui Wang (NSSC, CAS), Xiaowei Zhao (NSMC, CMA), Liping Yang (NSSC, CAS) + Miguel Querejeta - Two-dimensional PIC simulation of collective Thomson scattering in a beam-plasma system - https://arxiv.org/abs/2512.09949 - arXiv:2512.09949v1 Announce Type: new -Abstract: Collective Thomson scattering (CTS) in a beam-plasma system is reproduced by using 2D PIC simulations and the characteristics of the scattered wave spectrum are examined. By formulating the geometric shape of the scattered wave spectrum in wave number space, where the velocity vector of the beam component and the wave vectors of the incident and scattered waves are arbitrary, it is demonstrated that the spectrum in 2D wave number space becomes asymmetric. The spectrum of scattered waves propagating in a specific direction is presented as a function of wavelength to show that the electron (ion) feature is amplified and becomes asymmetric or distorted when Buneman (ion acoustic) instability occurs. An additional simulation is conducted for a weak, linearly stable beam-plasma system with a hot beam, and confirmed that the obtained scattered wave spectrum shows asymmetric feature. The results are expected to be applicable to the interpretation of radar observations of ionospheric plasmas as well as CTS measurements in laboratory plasmas. - oai:arXiv.org:2512.09949v1 - physics.plasm-ph - astro-ph.HE - physics.space-ph - Fri, 12 Dec 2025 00:00:00 -0500 + A Reduced Action Integral for Photon-Photon Interactions in Vacuum + https://arxiv.org/abs/2512.15731 + arXiv:2512.15731v1 Announce Type: new +Abstract: Electromagnetic waves propagating through vacuum can polarize virtual electron-positron pairs; this polarization, in turn, nonlinearly modifies their propagation. A semi-classical nonlinear wave equation describing the propagation is derived from the Euler--Heisenberg Lagrangian density, which captures vacuum polarization effects up to the one-loop level. Here, we present a reduced-action-integral approach that enables rapid modeling of nonlinear phenomena arising from the Euler--Heisenberg Lagrangian. Application of the variational principle to the reduced action provides equations of motion for familiar light-pulse parameters, such as spot size, phase, polarization, and phase-front curvature, without requiring full-field simulations. Three examples demonstrate the utility of the approach: phase modulation, birefringence, and frequency mixing. + oai:arXiv.org:2512.15731v1 + physics.optics + Fri, 19 Dec 2025 00:00:00 -0500 new http://creativecommons.org/licenses/by/4.0/ - Yuma Sato, Shuichi Matsukiyo + D. Ramsey, M. S. Formanek, J. P. Palastro - The meaning of "Big Bang" - https://arxiv.org/abs/2512.09950 - arXiv:2512.09950v1 Announce Type: new -Abstract: What does ``Big Bang'' actually mean? What was the origin of these two words? It has often been said that the expression ``Big Bang'' began as an insult. Even if this were true, it would be just an irrelevant part of the whole issue. There are many more aspects hidden under this name, and which are seldom explained. They will be discussed in this work. In order to frame the analysis, help will be sought from the highly authoritative voices of two exceptional writers: William Shakespeare and Umberto Eco. Both Shakespeare and Eco have explored the tension existing between words and the realities they name. With the conclusion that names are, in general, just labels, simple stickers put to identify things. And this includes those given to great theorems or spectacular discoveries. Not even ``Pythagoras' theorem'' was discovered by Pythagoras, as is now well-known. Stigler's law of eponymy is recalled to further substantiate those statements. These points will be at the heart of the investigation carried out here, concerning the very important concept of ``Big Bang''. Everybody thinks to know what ``the Big Bang'' is, but only very few do know it, in fact. When Fred Hoyle first pronounced these two words together, on a BBC radio program, listeners were actually left with the false image that Hoyle was trying to destroy. That is, the tremendous explosion of Lema\^itre's primeval atom (or cosmic egg), which scattered all its enormous matter and energy content throughout the rest of the Universe. This image is absolutely wrong! As will be concluded, today the label ``Big Bang'' is used in several different contexts: (a) the Big Bang Singularity; (b) as the equivalent of cosmic inflation; (c) speaking of the Big Bang cosmological model; (d) to name a very popular TV program; and more. - oai:arXiv.org:2512.09950v1 - physics.pop-ph - astro-ph.CO - gr-qc - math-ph - math.MP - physics.hist-ph - Fri, 12 Dec 2025 00:00:00 -0500 + Tree Tensor Networks Methods for Efficient Calculation of Molecular Vibrational Spectra + https://arxiv.org/abs/2512.15875 + arXiv:2512.15875v1 Announce Type: new +Abstract: We develop and employ general Tree Tensor Networks (TTNs) to compute the vibrational spectra for two model systems: a set of 64-dimensional coupled oscillators and acetonitrile. We explore various tree architectures, ranging from the simple linear structure of Matrix Product States (MPS), to trees where only the leaf nodes carry a physical leg -- as seen in the underlying ansatz of the Multilayer Multiconfiguration Time-Dependent Hartree (ML-MCTDH) method -- and further to more general trees in which all nodes are allowed to possess a physical leg. In addition, we implement Locally Optimal Block Preconditioned Conjugate Gradient (LOBPCG) methods and Inverse Iteration methods as eigensolvers. By means of comprehensive benchmarking of runtime and accuracy, we demonstrate that sub-wavenumber accuracy in vibrational spectra is achievable with all TTN structures. MPS and three-legged tree tensor network states (T3NS) have similar runtimes, whereas leaf-only trees require significantly more time. All numerical simulations were performed using PyTreeNet, a Python package designed for flexible tensor network computations. + oai:arXiv.org:2512.15875v1 + physics.chem-ph + quant-ph + Fri, 19 Dec 2025 00:00:00 -0500 new - http://creativecommons.org/licenses/by/4.0/ - Emilio Elizalde + http://creativecommons.org/licenses/by-sa/4.0/ + Shuo Sun, Richard M. Milbradt, Stefan Knecht, Chandan Kumar, Christian B. Mendl - The Eschatian Hypothesis - https://arxiv.org/abs/2512.09970 - arXiv:2512.09970v1 Announce Type: new -Abstract: The history of astronomical discovery shows that many of the most detectable phenomena, especially detection firsts, are not typical members of their broader class, but rather rare, extreme cases with disproportionately large observational signatures. Motivated by this, we propose the Eschatian Hypothesis: that the first confirmed detection of an extraterrestrial technological civilization is most likely to be an atypical example, one that is unusually "loud" (i.e., producing an anomalously strong technosignature), and plausibly in a transitory, unstable, or even terminal phase. Using a toy model, we derive conditions under which such loud civilizations dominate detections, finding for example that if a society is loud for only $10^{-6}$ of its lifetime, it must emit ${\gtrsim}1$% of its total observable energy budget during that phase to outrun quieter populations. The hypothesis naturally motivates agnostic anomaly searches in wide-field, multi-channel, continuous surveys as a practical strategy for a first detection of extraterrestrial technology. - oai:arXiv.org:2512.09970v1 - physics.pop-ph - astro-ph.IM - Fri, 12 Dec 2025 00:00:00 -0500 + Macroscopic Brownian Motion on a Chaotic Fluid Interface + https://arxiv.org/abs/2512.15917 + arXiv:2512.15917v1 Announce Type: new +Abstract: Brownian motion is the erratic motion of an object due to collisions with the fluid in which it is immersed. In this work, we detail a tabletop laboratory demonstration of underdamped Brownian motion wherein a macroscopic particle resting on a driven fluid interface exhibits ballistic motion at short times and diffusive motion at long times. We observe the trajectory of a millimetric disk driven by a field of chaotic Faraday waves excited by a shaker. The crossover from ballistic to diffusive motion occurs at time and length scales experimentally accessible through particle tracking of a video recorded with a standard phone camera. Along with representative data, we provide a complete assembly guide, and operating procedure for students so that the experiment can be readily applied in the classroom. The tabletop setup can also be adapted for other student projects and active research topics relating to particle motion on a vibrating fluid interface. + oai:arXiv.org:2512.15917v1 + physics.ed-ph + physics.flu-dyn + Fri, 19 Dec 2025 00:00:00 -0500 new http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - David Kipping + Jack-William Barotta, Caroline M. Barotta, Eli Silver, Daniel M. Harris - Corkscrew motion of Trypanosome brucei is driven by helical beating of the flagellum and facilitated by its bent shape - https://arxiv.org/abs/2512.10021 - arXiv:2512.10021v1 Announce Type: new -Abstract: In the pathogenic parasite Trypanosoma brucei, a laterally attached flagellum drives rapid deformation of the complex cell body, producing puzzling dynamics. High-speed defocusing imaging reveals that surface points trace flower-like patterns in transverse planes. The petals arise from clockwise flagellar beating, which generates a right-handed helical wave propagating from the anterior tip along the body, advancing the cell like a twisted corkscrew. The central lobes result from slower counterclockwise body rotation required to balance the active torque. The bent cell shape underneath the flagellum superimposes these two chiral motions at different radial distances, producing the observed patterns. Three-dimensional hydrodynamic simulations using the method of regularized Stokeslets reproduce these dynamics and show that bent cell shape enhances swimming, suggesting an adaptive advantage of T. brucei's morphology. - oai:arXiv.org:2512.10021v1 - physics.bio-ph - physics.flu-dyn - Fri, 12 Dec 2025 00:00:00 -0500 + Tensor network approaches for plasma dynamics + https://arxiv.org/abs/2512.15924 + arXiv:2512.15924v1 Announce Type: new +Abstract: The dynamics of plasmas are governed by a set of non-linear differential equations which remain challenging to solve directly for large 2D and 3D problems. Here we investigate how tensor networks could be applied to plasmas described by the Vlasov-Maxwell system of equations and investigate parameter regimes which show promise for efficient simulations. We show for low-dimensional problems that the simplest form of tensor networks known as a Matrix Product State performs sufficiently well, however in regimes with a strong permanent magnetic field or high-dimensional problems one may need to consider alternative tensor network geometries. We conclude the study of the Vlasov-Maxwell system with the application of tensor networks to an industrially relevant test case and validate our results against state of the art plasma solvers based on Particle-In-Cell codes. We also extend the application of tensor networks to the alternative plasma description of Magnetohydrodynamics and outline how this can be encoded using Matrix Product States. + oai:arXiv.org:2512.15924v1 + physics.plasm-ph + quant-ph + Fri, 19 Dec 2025 00:00:00 -0500 new http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Sizhe Cheng, Devadyouti Das, Mykhaylo Barchuk, Raveen Armstrong, Michele M. Klingbeil, Becca Thomases, Shuang Zhou + Ryan J. J. Connor, Preetma Soin, Callum W. Duncan, Andrew J. Daley - The role of modes in nonlinear fiber optical computing - https://arxiv.org/abs/2512.10035 - arXiv:2512.10035v1 Announce Type: new -Abstract: We investigate the nonlinear propagation of light in graded-index multimode fiber, utilizing it as an optical computing unit, and quantify how it employs waveguide modes to process information. Using a time-dependent spatiotemporal propagation model with modal decomposition, we evaluate several benchmark regression and classification tasks and study the modal content of the generated speckles, which couples with a simple digital layer to perform optical computing. Analysis of modal entropy and energy-based mode counts reveals that effective computation is confined to a low-dimensional modal subspace, whose identity depends on the task and propagation regime. This also sets a trade-off between modal richness and nonlinear beam self-cleaning. These results establish modal statistics as practical design metrics for fiber-based optical computers. - oai:arXiv.org:2512.10035v1 + Off resonant Fano enhanced single molecule resolution imaging with a CW source + https://arxiv.org/abs/2512.15936 + arXiv:2512.15936v1 Announce Type: new +Abstract: Apertureless scanning near-field optical microscopy (a-SNOM) is typically limited to ~10 nm resolution by the tip apex size. We demonstrate that ~1-nm resolution can be achieved under continuous-wave (CW) illumination by exploiting Fano path interference. A defect center that naturally forms at the apex of a metal-coated AFM tip acts as a quantum object and induces Fano interference, forcing a stronger but normally off-resonant plasmonic mode (597 nm) to operate effectively on resonance at the driving wavelength (520 nm). Because this interference occurs only beneath the defect, a ~1-nm-wide, strongly enhanced near-field hotspot is created. Using this off-resonant Fano-enhanced field, we achieve single-molecule-resolution imaging based on exact three-dimensional Maxwell simulations. + oai:arXiv.org:2512.15936v1 physics.optics - Fri, 12 Dec 2025 00:00:00 -0500 + Fri, 19 Dec 2025 00:00:00 -0500 new - http://creativecommons.org/licenses/by-nc-nd/4.0/ - Firdevs Y\"uce, Bora \c{C}arp{\i}nl{\i}o\u{g}lu, U\u{g}ur Te\u{g}in + http://arxiv.org/licenses/nonexclusive-distrib/1.0/ + Rasim Volga Ovali, Mehmet Emre Tasgin + + + Full-field-of-view aberration correction for large arrays of focused beams + https://arxiv.org/abs/2512.15967 + arXiv:2512.15967v1 Announce Type: new +Abstract: We propose and implement an aberration correction method for the creation of extended arrays of spots well beyond the isoplanatic region of any optical system. The method relies on an extensive calibration of aberrations in terms of Zernike polynomials over the full accessible field of an optical system. We introduce a modified Gerchberg-Saxton algorithm for generating holographic phase masks creating fully corrected arbitrary arrays of spots. By applying the method to an aspherical lens, and using a liquid-crystal spatial light modulator (SLM), we increase the aberration-free field of view from 50 to 500 $\mu$m, only limited by the largest diffraction angles accessible to the SLM. This opens new perspectives for the generation of large arrays of optical tweezers, especially for neutral atom based quantum processors and simulators. + oai:arXiv.org:2512.15967v1 + physics.optics + quant-ph + Fri, 19 Dec 2025 00:00:00 -0500 + new + http://creativecommons.org/licenses/by-nc-sa/4.0/ + Yohann Machu, Gautier Creutzer, Cl\'ement Sayrin, Michel Brune - Identifying Neutron Sources using Recoil and Time-of-Flight Spectroscopy - https://arxiv.org/abs/2512.10044 - arXiv:2512.10044v1 Announce Type: new -Abstract: Neutron-source identification is central to nuclear physics and its applications, from planetary science to nuclear security, yet direct discrimination from neutron spectra remains fundamentally elusive. Here, we introduce a Bayesian protocol that directly infers source ensembles from measured neutron spectra by combining full-spectrum template matching with probabilistic evidence evaluation. Applying this protocol to recoil and time-of-flight spectroscopy, we recover single- and two-source configurations with strong statistical significance ($>\!\!4\sigma$) at event counts as low as $\sim\!\!10^{3}$. These results demonstrate that neutron spectral signatures can be leveraged for robust source identification, opening a new observational window for both fundamental research and operationally driven applications. - oai:arXiv.org:2512.10044v1 + Measurement of Light Yield Response of Gd-compatible Water-based Liquid Scintillator with the Brookhaven 1-ton testbed + https://arxiv.org/abs/2512.15968 + arXiv:2512.15968v1 Announce Type: new +Abstract: The Water-based Liquid Scintillator (WbLS) enables hybrid detection by combining scintillation and Cherenkov signals, providing superior event reconstruction capabilities compared to conventional neutrino detectors. We measured the light yield of Gd-compatible WbLS at varying concentrations from 0.35\% to 1\% by mass, using cosmic-ray muons in a 1-ton scale detector at BNL. The light yield is measured as (69.16 $\pm$ 6.92) ph / MeV at 0.35\% concentration, which increased to (87.32 $\pm$ 8.73) ph / MeV at 1\%. These results establish a quantitative basis for optimizing future WbLS-based detectors in neutrino physics. + oai:arXiv.org:2512.15968v1 physics.ins-det + hep-ex nucl-ex - physics.app-ph - physics.data-an - Fri, 12 Dec 2025 00:00:00 -0500 + Fri, 19 Dec 2025 00:00:00 -0500 new http://creativecommons.org/licenses/by/4.0/ - David Breitenmoser, Ricardo Lopez, Shaun D. Clarke, Sara A. Pozzi + S. Gwon, M. Askins, D. M. Asner, A. Baldoni, D. F. Cowen, R. Diaz Prerez, M. V. Diwan, S. Gokhale, S. Hans, P. Kumar, G. Lawley, S. Linden, G. D. Orebi Gann, J. Park, C. Reyes, R. Rosero, K. Siyeon, M. Smiley, J. J. Wang, M. Wilking, G. Yang, M. Yeh - Generation of Perfectly Achromatic Optical Vortices Using a Compensated Tandem Twisted Nematic Cell - https://arxiv.org/abs/2512.10090 - arXiv:2512.10090v1 Announce Type: new -Abstract: The generation of white optical vortices is currently constrained by intrinsic trade-offs between spectral bandwidth, conversion efficiency, and temporal pulse integrity in conventional diffractive and geometric-phase approaches. In this work, we theoretically investigate a compensated tandem crossed twisted nematic (TN) liquid crystal architecture that overcomes these fundamental limitations. By developing a rigorous Jones matrix model and defining specific figures of merit for chromatic fidelity, we analyze the impact of manufacturing imperfections and non-adiabatic waveguiding (deviations from the Mauguin regime) on the device performance. We propose and evaluate three distinct compensation strategies, ranging from optimized passive designs for specific manufacturing tolerances to a robust active compensation scheme utilizing a tunable retarder. Our analysis demonstrates that the active approach effectively nullifies parasitic amplitude modulation, enabling the generation of perfectly achromatic vortices with high phase purity across an arbitrary bandwidth. This establishes the compensated tandem TN cell as a superior and versatile platform for high-fidelity white-light singular optics. - oai:arXiv.org:2512.10090v1 + Optical coprocessor based on spontaneous Brillouin scattering + https://arxiv.org/abs/2512.15970 + arXiv:2512.15970v1 Announce Type: new +Abstract: Analog coprocessors for neural networks are an intensively developing field. They provide approximate results of computations for relatively low energy cost and at high speed. We show that a set of ring resonators with Brillouin interaction between photons and phonons, being coupled to a waveguide, can be used to implement matrix-vector multiplication. The input vector is formed by occupancies of the anti-Stokes optical modes pumped via spontaneous Brillouin scattering, i.e, scattering on thermal phonons. Brillouin scattering rates and coupling constants between ring resonators and the waveguide form the matrix. The system allows for parallel computations in frequency band. + oai:arXiv.org:2512.15970v1 physics.optics - cond-mat.soft - Fri, 12 Dec 2025 00:00:00 -0500 + quant-ph + Fri, 19 Dec 2025 00:00:00 -0500 new - http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Dmytro O. Plutenko, Mikhail V. Vasnetsov + http://creativecommons.org/licenses/by-nc-nd/4.0/ + I. V. Vovchenko, A. A. Zyablovsky, A. A. Pukhov, E. S. Andrianov + + + Exploring Overlapping Mechanisms of Dynamic Nuclear Polarization in Type 1b HPHT Diamond + https://arxiv.org/abs/2512.15982 + arXiv:2512.15982v1 Announce Type: new +Abstract: The inhomogeneous distribution of P1 centers in type 1b HPHT diamond samples allows multiple DNP mechanisms to occur within the same crystal, resulting in complex DNP spectra. At some crystal orientations, different DNP mechanisms can compete to drive hyperpolarization with different signs at the same applied microwave frequency. We perform microwave-irradiated DNP using both monochromatic and frequency-modulated microwave excitation to explore the competition between these DNP mechanisms in diamond at room temperature. We demonstrate that frequency-modulated DNP is a tool for suppressing certain DNP mechanisms while enhancing others in a single-crystal diamond sample. Frequency modulation also enables higher enhancement of the NMR signal beyond traditional monochromatic DNP under some conditions. In a powder sample, competing enhancement mechanisms can also arise from different crystallite orientations in the powder. We observe that at certain microwave frequencies the DNP signal changes sign during the polarization build-up, even with monochromatic microwave irradiation. We do not observe this phenomenon in any single-crystal spectrum. We discuss both methods of investigating competing mechanisms of DNP as a means of selectively enhancing different DNP mechanisms driving $^{13}$C NMR signal enhancement. + oai:arXiv.org:2512.15982v1 + physics.chem-ph + cond-mat.mtrl-sci + Fri, 19 Dec 2025 00:00:00 -0500 + new + http://creativecommons.org/licenses/by/4.0/ + Brendan C. Sheehan, Margaret Hubble, Daphna Shimon, Chandrasekhar Ramanathan - Investigation of Real-Space Transfer Noise in InP Quantum Wells - https://arxiv.org/abs/2512.10103 - arXiv:2512.10103v1 Announce Type: new -Abstract: Indium phosphide (InP) high electron-mobility transistors (HEMTs) are widely used in many fields such as quantum computing because of their unparalleled microwave noise performance. Achieving improved noise performance requires a physical understanding of the noise mechanisms. Here, we experimentally test a theoretical proposal for drain (output) noise as originating in part from real-space transfer (RST) by characterizing the microwave noise temperature of transfer-length method structures with the same channel composition but two different barrier compositions. This choice was made to alter the confining potential of electrons in the channel, thereby affecting the RST mechanism, while avoiding changes to the channel transport properties. We observe trends of noise temperature with physical temperature and source-drain voltage which are compatible with the predictions of RST noise theory. This finding supports the hypothesis that RST contributes to drain noise in HEMTs. - oai:arXiv.org:2512.10103v1 + Vertical NAND in a Ferroelectric-driven Paradigm Shift + https://arxiv.org/abs/2512.15988 + arXiv:2512.15988v1 Announce Type: new +Abstract: Over the past decades, the relentless scaling and mass production of flash memory have underpinned the data-centric era. Yet charge-trap-based 3D NAND flash is now constrained by intrinsic physical and architectural limits, including reliability degradation at the device level, high operating power at the array level, and vertical scaling saturation at the system level. These bottlenecks hinder further advances in storage density and energy efficiency required by memory-centric computing. This Perspective outlines how coupling ferroelectric polarization with charge trapping can reconfigure the foundations of flash memory. In these hybrid architectures, polarization offers an energy-efficient pathway for charge modulation through enhanced Fowler-Nordheim tunneling, while trapped charges reinforce polarization-driven states to ensure stability. Such synergistic dynamics enable low-voltage operation and integration beyond one thousand layers without compromising process compatibility. We discuss the material, device, and architectural transitions required to realize this hybrid technology and chart future research directions to overcome the remaining scaling bottlenecks. Hybrid ferroelectric NAND extends conventional flash toward a scalable and energy-efficient platform, marking a paradigm shift for next-generation non-volatile memory. + oai:arXiv.org:2512.15988v1 physics.app-ph - Fri, 12 Dec 2025 00:00:00 -0500 + Fri, 19 Dec 2025 00:00:00 -0500 new http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Jiayin Zhang, Anthony J. Ardizzi, Kieran A. Cleary, Austin J. Minnich + Giuk Kim, Hyojun Choi, Prasanna Venkat Ravindran, Moonyoung Jung, Sanghyun Park, Kijoon Kim, Suhwan Lim, Kwangyou Seo, Kwangsoo Kim, Wanki Kim, Daewon Ha, Sukjoong Shin, Asif Khan, Sanghun Jeon, Kai Ni - Unifying Theories in High-Dimensional Biology: Approaches, Challenges and Opportunities - https://arxiv.org/abs/2512.10111 - arXiv:2512.10111v1 Announce Type: new -Abstract: Across biological subdisciplines, the last decade has seen an explosion of high-dimensional datasets, including datasets for cells, species, immune systems, neurons and behaviour. At the ICTS workshop 'Unifying Theories in High-Dimensional Biophysics' we discussed whether this high dimensionality poses a challenge or opportunity for describing, understanding and predicting biological systems theoretically. We discussed methods, models and frameworks that can help with addressing empirical observations based on these high-dimensional datasets. We summarize the challenges and opportunities that emerged in discussions according to individual participants below. - oai:arXiv.org:2512.10111v1 - physics.bio-ph - Fri, 12 Dec 2025 00:00:00 -0500 + Analytical Solutions for Turbulent Channel Flow Using Alexeev and Navier-Stokes Hydrodynamic Equations: Comparison with Experiments + https://arxiv.org/abs/2512.15995 + arXiv:2512.15995v1 Announce Type: new +Abstract: Understanding turbulent boundary layer flows is important for many application areas. Enhanced theoretical models may provide deeper insights into the fundamental mechanisms of turbulence that elude current models; therefore, the search for improved kinetic equations and their respective hydrodynamic equations continues. In this work, we consider the Generalized Boltzmann Equation (GBE), proposed by Alexeev (1994). The GBE accounts for finite particle size and the variation of the distribution function over timescales of the order of the collision time. The Alexeev hydrodynamic equations are derived from the GBE. + In this work, the Alexeev hydrodynamic equations (AHE) and Navier-Stokes (NS) equations are solved analytically for turbulent channel flow under the assumption that stationary solutions yield the mean flow velocity. The analytical solutions of the AHE are validated by numerical solutions and compared with the NS solutions and experimental data for turbulent channel flow from multiple sources, spanning Reynolds numbers from 3,000 to 35,000,000. Solutions of the AHE demonstrate significantly better agreement with experimental data than those obtained from the NS equations. The analytical solution revealed a new similarity parameter: the boundary layer thickness scale, which coincides with the Kolmogorov microscale observed in experiments. The mechanisms for turbulence generation and control are discussed. + oai:arXiv.org:2512.15995v1 + physics.flu-dyn + Fri, 19 Dec 2025 00:00:00 -0500 new http://creativecommons.org/licenses/by/4.0/ - Marianne Bauer, Akshit Goyal, Sidhartha Goyal, Gautam Reddy, Shaon Chakrabarti, Michael M Desai, William Gilpin, Jacopo Grilli, Kabir Husain, Sanjay Jain, Mohit Kumar Jolly, Kyogo Kawaguchi, Aneta Koseska, Milo Lin, Leelavati Narlikar, Simone Pigolotti, Archishman Raju, Krishna Shrinivas, Rahul Siddharthan, Greg J Stephens, Andreas Tiffeau-Mayer, Suriyanarayanan Vaikuntanathan + Alex Fedoseyev - A Computational Procedure for Assessing I$_c$($\varepsilon$) in Nb$_3$Sn/Bi-2212 Hybrid Magnets - https://arxiv.org/abs/2512.10119 - arXiv:2512.10119v1 Announce Type: new -Abstract: The critical current of superconductors is commonly measured by testing unloaded wires under an external magnetic field. While stressed by intense Lorentz forces, the existing HTS/LTS superconductors are prone to a reduction in critical current before reaching their structural mechanical limit. In this work, the magnetic and mechanical analysis of the FNAL 4-layer Bi-2212/Nb$_3$Sn hybrid dipole magnet is reported, aimed at predicting the critical current degradation for both the superconductors during powering at 16 T. All the Rutherford cables in the coils of the hybrid magnet were modeled at the strand level in Ansys APDL with the heterogeneous cable model. Utilizing this detailed geometry, it was possible to evaluate the effects of strain on the critical current degradation for both the Nb$_3$Sn and Bi-2212 superconductors under the intense Lorentz forces. The analysis presented in this paper integrates strain-dependent critical current laws, with parameters derived from experimental data, to simulate the hybrid magnet's performance for all possible current-powering configurations. The proposed methodology enables a detailed assessment of conductor integrity and I$_C$($\varepsilon$) reduction in existing hybrid magnet designs, providing a versatile and rigorous framework for optimizing future high-field hybrid magnets. - oai:arXiv.org:2512.10119v1 - physics.ins-det - Fri, 12 Dec 2025 00:00:00 -0500 + Sparse Operator-Adapted Wavelet Decomposition Using Polygonal Elements for Multiscale FEM Problems + https://arxiv.org/abs/2512.16004 + arXiv:2512.16004v1 Announce Type: new +Abstract: We develop a sparse multiscale operator-adapted wavelet decomposition-based finite element method (FEM) on unstructured polygonal mesh hierarchies obtained via a coarsening procedure. Our approach decouples different resolution levels, allowing each scale to be solved independently and added to the entire solution without the need to recompute coarser levels. At the finest level, the meshes consist of triangular elements which are geometrically coarsened at each step to form convex polygonal elements. Smooth field regions of the domain are solved with fewer, larger, polygonal elements, whereas high-gradient regions are represented by smaller elements, thereby improving memory efficiency through adaptivity. The proposed algorithm computes solutions via sequences of hierarchical sparse linear-algebra operations with nearly linear computational complexity. + oai:arXiv.org:2512.16004v1 + physics.comp-ph + cs.NA + math.NA + Fri, 19 Dec 2025 00:00:00 -0500 new http://creativecommons.org/licenses/by/4.0/ - 10.1109/TASC.2025.3624725 - IEEE Trans.Appl.Supercond. 36, 3 (2026) 8400205 - A. D'Agliano (Lawrence Berkeley National Laboratory, Pisa University), A. V. Zlobin (Fermi National Accelerator Laboratory), I. Novitski (Fermi National Accelerator Laboratory), G. Vallone (Lawrence Berkeley National Laboratory), P. Ferracin (Lawrence Berkeley National Laboratory), E. Barzi (Ohio State University), S. Donati (Pisa University), V. Giusti (Pisa University) + Furkan \c{S}{\i}k, F. L. Teixeira, B. Shanker - A Model-Guided Neural Network Method for the Inverse Scattering Problem - https://arxiv.org/abs/2512.10123 - arXiv:2512.10123v1 Announce Type: new -Abstract: Inverse medium scattering is an ill-posed, nonlinear wave-based imaging problem arising in medical imaging, remote sensing, and non-destructive testing. Machine learning (ML) methods offer increased inference speed and flexibility in capturing prior knowledge of imaging targets relative to classical optimization-based approaches; however, they perform poorly in regimes where the scattering behavior is highly nonlinear. A key limitation is that ML methods struggle to incorporate the physics governing the scattering process, which are typically inferred implicitly from the training data or loosely enforced via architectural design. In this paper, we present a method that endows a machine learning framework with explicit knowledge of problem physics, in the form of a differentiable solver representing the forward model. The proposed method progressively refines reconstructions of the scattering potential using measurements at increasing wave frequencies, following a classical strategy to stabilize recovery. Empirically, we find that our method provides high-quality reconstructions at a fraction of the computational or sampling costs of competing approaches. - oai:arXiv.org:2512.10123v1 - physics.comp-ph - cs.LG - Fri, 12 Dec 2025 00:00:00 -0500 + Precision continuous-wave laser measurement of the $\text{1}^\text{3}\text{S}_\text{1} \to \text{2}^\text{3}\text{S}_\text{1}$ interval in positronium + https://arxiv.org/abs/2512.16018 + arXiv:2512.16018v1 Announce Type: new +Abstract: We report a 4.9\,ppb measurement of the positronium $\text{1}^\text{3}\text{S}_\text{1} \to \text{2}^\text{3}\text{S}_\text{1}$ interval using continuous-wave two-photon laser spectroscopy. The transition is detected via photoionization by the same excitation laser. The resulting positrons are guided to a microchannel plate detector, surrounded by scintillators to detect the annihilation photons in coincidence, thereby reducing the background. A Monte Carlo lineshape simulation, accounting for effects such as the second-order Doppler shift and the AC Stark shift, is used to extract a transition frequency of $1233607224.1(6.0)\,\text{MHz}$, consistent with the previous 2.6\,ppb determination of this transition and with the most recent QED calculations at order $\mathcal{O}(\alpha^7\ln^2(1/\alpha))$, which predict $1233607222.12(58)\,\text{MHz}$. Combining the two measurements gives $1233607218.1(2.8)\,\text{MHz}$, reducing the tension with QED to about $1.4\,\sigma$. We also present a semi-analytical lineshape model of $\text{1}^\text{3}\text{S}_\text{1} \to \text{2}^\text{3}\text{S}_\text{1}$ of positronium, which shows excellent agreement with detailed simulations and is validated by the experimental data. This expands on previous work with stable atoms by incorporating effects such as limited lifetime of the atoms, photoionization and AC Stark shift. The lineshape modelling is also applicable to other unstable systems, such as muonium. This provides a powerful tool for optimizing the experimental parameters and gaining deeper insights without the need for computationally intensive simulations. + oai:arXiv.org:2512.16018v1 + physics.atom-ph + hep-ex + Fri, 19 Dec 2025 00:00:00 -0500 new - http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Olivia Tsang, Owen Melia, Vasileios Charisopoulos, Jeremy Hoskins, Yuehaw Khoo, Rebecca Willett + http://creativecommons.org/licenses/by/4.0/ + Lucas de Sousa Borges, Edward Thorpe-Woods, Evans Javary, Paolo Crivelli - Generative Modeling of Entangled Polymers with a Distance-Based Variational Autoencoder - https://arxiv.org/abs/2512.10131 - arXiv:2512.10131v1 Announce Type: new -Abstract: We present a variational autoencoder framework for learning and generating configurations of structured polymer globules from distance matrices. We used coarse-grained molecular dynamics to sample polyethylene structures, which we used as the training set for our deep learning model. By combining convolution and attention layers, the model encodes the structural patterns of distance matrices into an organized and roto-translationally invariant latent space of lower dimensionality. The generative capability of the variational autoencoder, coupled with a post-processing pipeline based on multidimensional scaling and short molecular dynamics, enables the recovery of physically meaningful configurations. The reconstructed and generated samples reproduce key observables, including energy, size, and entanglement, despite minor discrepancies in the raw decoder output. - oai:arXiv.org:2512.10131v1 - physics.comp-ph - Fri, 12 Dec 2025 00:00:00 -0500 + Share, Rotate, Split: The Effects of Group Work Role Distributions on Student Outcomes + https://arxiv.org/abs/2512.16094 + arXiv:2512.16094v1 Announce Type: new +Abstract: Education literature recommends many different strategies for structuring student group work in labs. Many of these strategies, however, have not been sufficiently evaluated for their effects on student outcomes. One prior study suggested that sharing roles, rather than splitting roles, in lab groups can boost students' physics interest and self-efficacy. Here, we expand upon this literature by evaluating the effects of a broader range of role distributions across several student outcomes from a large sample at two different institutions. We developed a survey item to probe the ways students distribute their roles in lab groups. The item asks for the percent of time in lab they spent working together on lab roles (sharing), working alone on roles but rotating each session (rotating), and working alone in the same role throughout the semester (splitting). We employed hierarchical linear modeling to measure the effects of these role distributions on student critical thinking, self-efficacy, perceived agency, belonging, and sense of recognition based on survey items specific to physics lab contexts. We found that role distributions did not differentially impact student critical thinking. We also found that sharing roles tended to have a positive impact on student attitudes; splitting had a negative effect on attitudes; and rotating fell in between. Statistical significance varied across these attitudinal outcomes. Our findings invite further research and controlled studies to better understand the apparent benefits of sharing, rotating, and splitting roles in introductory physics labs. + oai:arXiv.org:2512.16094v1 + physics.ed-ph + Fri, 19 Dec 2025 00:00:00 -0500 new - http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Pietro Chiarantoni, Oscar Serra, Mohammad Erfan Mowlaei, Venkata Surya Kumar Choutipalli, Mark DelloStritto, Xinghua Shi, Micheal L. Klein, Vincenzo Carnevale + http://creativecommons.org/licenses/by/4.0/ + Jacob Feinleib, Matthew Dew, N. G. Holmes - {\mu}RWELL-PICOSEC: Precision Timing with Resistive Micro-Well Detector - https://arxiv.org/abs/2512.10137 - arXiv:2512.10137v1 Announce Type: new -Abstract: The PICOSEC detector concept uses a micro-pattern gaseous detector (MPGD) amplification structure combined with a Cerenkov radiator coated with a semi-transparent photocathode to provide below tens of picosecond-level precision timing capabilities with minimum ionizing particles. PICOSEC has triggered interest in the development of time-of-flight detectors for particle identification and timing detectors for track reconstruction in the high rate environment of future nuclear and high energy physics experiments. The PICOSEC Micromegas (or PICOSEC-MM) detector, developed by the CERN-based PICOSEC collaboration, use the Micromegas structure for gaseous amplification and achieve below 20 ps timing resolution. A new type of PICOSEC detector, the {\mu}RWELL-PICOSEC based on {\mu}RWELL amplification structure, is being investigated at Thomas Jefferson National Accelerator Facility (Jefferson Lab) alongside PICOSEC-MM R&D efforts in Europe. Preliminary results from the two 2024 beam test campaigns at CERN demonstrate a timing performance better than 24 ps is achievable with a single-channel {\mu}RWELL-PICOSEC prototype. A vigorous R&D effort is ongoing to improve the timing performance, robustness and operational stability of {\mu}RWELL-PICOSEC detectors. Development of a large size {\mu}RWELL-PICOSEC is also under consideration for applications in large scale experiments. - oai:arXiv.org:2512.10137v1 - physics.ins-det - Fri, 12 Dec 2025 00:00:00 -0500 + ClusTEK: A grid clustering algorithm augmented with diffusion imputation and origin-constrained connected-component analysis: Application to polymer crystallization + https://arxiv.org/abs/2512.16110 + arXiv:2512.16110v1 Announce Type: new +Abstract: Grid clustering algorithms are valued for their efficiency in large-scale data analysis but face persistent limitations: parameter sensitivity, loss of structural detail at coarse resolutions, and misclassifications of edge or bridge cells at fine resolutions. Previous studies have addressed these challenges through adaptive grids, parameter tuning, or hybrid integration with other clustering methods, each of which offers limited robustness. This paper introduces a grid clustering framework that integrates Laplacian-kernel diffusion imputation and origin-constrained connected-component analysis (OC-CCA) on a uniform grid to reconstruct the cluster topology with high accuracy and computational efficiency. During grid construction, an automated preprocessing stage provides data-driven estimates of cell size and density thresholds. The diffusion step then mitigates sparsity and reconstructs missing edge cells without over-smoothing physical gradients, while OC-CCA constrains component growth to physically consistent origins, reducing false merges across narrow gaps. Operating on a fixed-resolution grid with spatial indexing ensures the scaling of O(nlog n). Experiments on synthetic benchmarks and polymer simulation datasets demonstrate that the method correctly manages edges, preserves cluster topology, and avoids spurious connections. Benchmarking on polymer systems across scales (9k, 180k, and 989k atoms) shows that optimal preprocessing, combined with diffusion-based clustering, reproduces atomic-level accuracy and captures physically meaningful morphologies while delivering accelerated computation. + oai:arXiv.org:2512.16110v1 + physics.comp-ph + Fri, 19 Dec 2025 00:00:00 -0500 new - http://creativecommons.org/licenses/by-nc-nd/4.0/ - Kondo Gnanvo (for the PICOSEC Collaboration) + http://arxiv.org/licenses/nonexclusive-distrib/1.0/ + Elyar Tourani, Brian J. Edwards, Bamin Khomami - Momentum-space non-Hermitian skin effect in an exciton-polariton system - https://arxiv.org/abs/2512.10146 - arXiv:2512.10146v1 Announce Type: new -Abstract: Localization of a macroscopic number of eigenstates on a real-space boundary, known as the non-Hermitian skin effect, is one of the striking topological features emerging from non-Hermiticity. Realizing this effect typically requires periodic (lattice) systems with asymmetry of intersite coupling, which is not readily available in many physical platforms. Instead, it is meticulously engineered, e.g., in photonics, which results in complex structures requiring precise fabrication steps. Here, we propose a simpler mechanism: introducing an asymmetric, purely imaginary potential in a topologically trivial system induces momentum-space localization akin to the skin effect. We experimentally demonstrate this localization using exciton polaritons, hybrid light-matter quasi-particles in a simple engineered `round box' trap, pumped by a laser pump offset from the trap center. The effect disappears if the pump is concentric with the trap. The localization persists and becomes stronger at higher densities of polaritons, when a non-equilibrium Bose-Einstein condensate is formed and the system becomes nonlinear. Our approach offers a new route to realizing skin effects in continuous, non-periodic systems and exploring the interplay of non-Hermiticity, topology, and nonlinearity in macroscopic quantum states. - oai:arXiv.org:2512.10146v1 - physics.optics - cond-mat.mes-hall - Fri, 12 Dec 2025 00:00:00 -0500 + Wake transitions and melting dynamics of a translating sphere in warm liquid + https://arxiv.org/abs/2512.16117 + arXiv:2512.16117v1 Announce Type: new +Abstract: We investigate the three-dimensional melting dynamics of an initially spherical particle translating in a warmer liquid using sharp-interface simulations that fully resolve both solid and fluid phases with the Stefan condition. A wide parameter space is explored, spanning initial Reynolds number ($Re_0$), Stefan number ($St$), and Richardson number ($Ri$). In the absence of buoyancy ($Ri= 0$), the interface evolution is governed by canonical wake bifurcations. Four regimes are identified: an axi-symmetric regime ($Re_0<212$) with a rounded front and planar rear; a steady-planar-symmetric regime ($212<Re_0<273$) with an inclined rear plane; a periodic-planar-symmetric regime ($273<Re_0<355$) where vortex shedding emerges in the wake; and a chaotic regime ($Re_0>355$) with fluctuating stagnation points and a more rounded rear. Despite these differences, all regimes exhibit a tendency toward melt-rate homogenisation over time. Besides, we introduce an aspect-ratio-based surface-area formulation that yields a predictive model, accurately capturing volume evolution across regimes. Hydrodynamic loads also reflect the coupling between shape and flow: drag follows rigid-sphere correlations only at moderate $Re_0$; planar rears enhance drag at higher $Re_0$; lift appears only in symmetry-broken regimes and reverses late in time; torque reorients the rear plane toward vertical, consistent with free-body experiments. When buoyancy is included, assisting configurations ($Ri>0$) suppress recirculation and maintain quasi-spherical shapes, whereas opposing or transverse buoyancy ($Ri<0$) destabilises wakes and promotes tilted planar rears. These results provide a unified framework for convection-driven melting across laminar, periodic, and chaotic wakes, with implications for geophysical and industrial processes. + oai:arXiv.org:2512.16117v1 + physics.flu-dyn + Fri, 19 Dec 2025 00:00:00 -0500 new http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Yow-Ming (Robin), Hu, Mateusz Kr\'ol, Daria A. Smirnova, Lev A. Smirnov, Bianca Rae Fabricante, Karol Winkler, Martin Kamp, Christian Schneider, Sven H\"ofling, Timothy C. H. Liew, Andrew G. Truscott, Elena A. Ostrovskaya, Eliezer Estrecho + Zhong-Han Xue, Jie Zhang - Solid-state Laser Cooling - https://arxiv.org/abs/2512.10162 - arXiv:2512.10162v1 Announce Type: new -Abstract: Since the first proof-of-concept demonstrations of photoluminescence-based optical refrigeration, solid-state laser cooling has developed into a credible competitor to conventional cryogenic technologies. Solid-state laser cooling continues to advance as new materials push cooling limits. These developments have created a need to consolidate progress made to date as well as standardize critical experimental considerations needed for reliable and verifiable cooling measurements. This primer therefore outlines essential concepts and requirements, which underpin solid-state laser cooling. The primer summarizes key milestones achieved with cooling-grade, rare-earth-doped glasses and crystals as well as with semiconductors. It additionally highlights emerging applications of solid-state optical refrigeration. To strengthen the consistency and reproducibility of cooling results going forward, two reporting checklists are introduced. They cover materials, cooling metrics, and thermometry. This primer is intended to serve as both a tutorial and a practical reference for incoming and existing researchers involved in solid-state laser-cooling. - oai:arXiv.org:2512.10162v1 + A dispersion-driven 3D color near-eye meta-display + https://arxiv.org/abs/2512.16127 + arXiv:2512.16127v1 Announce Type: new +Abstract: Chromatic dispersion, an inherent wavelength-dependent phenomenon in optical systems, has traditionally been regarded as a detrimental effect to be minimized in imaging and display. Here, we present a paradigm shift by deliberately engineering and harnessing metalens dispersion as a functional mechanism for three-dimensional (3D) near-eye displays. Specifically, we exploit lateral dispersion to transform transverse offset between green and red objects into image-space angular separations that make their images intersected virtually, thereby creating color-merged 3D virtual-image perception. This meta-display architecture preserves compactness of conventional planar display while exhibiting less data requirements and lower hardware complexity than other near-eye 3D displays. Experimentally, we demonstrate a multi-color near-eye 3D system achieving an 11{\deg} field of view, 22 pixels-per-degree angular resolution, 0.9 m depth of field, and 19 distinct image planes. This work establishes a new pathway for metasurfaces toward visual displays and highlights great potential for future virtual/augmented reality. + oai:arXiv.org:2512.16127v1 physics.optics - physics.app-ph - physics.ins-det - Fri, 12 Dec 2025 00:00:00 -0500 + Fri, 19 Dec 2025 00:00:00 -0500 new http://creativecommons.org/licenses/by/4.0/ - Yang Ding, Shenghao Zhang, Alexander R. Albrecht, Zhaojie Feng, Lars Forberger, Hiroki Tanaka, Markus P. Hehlen, Galina Nemova, Peter J. Pauzauskie, Denis V. Seletskiy, Masaru Kuno + Zi Wang, Dong Zhao, Li Liang, Hengyi Wang, Yuan Liu, Fang-Wen Sun, Kun Huang - Heteronuclear and Homonuclear Vector Solitons in Lasers - https://arxiv.org/abs/2512.10198 - arXiv:2512.10198v1 Announce Type: new -Abstract: Vector solitons (VSs), being observed across various fields from optics to Bose-Einstein condensates, are localized structures composed of orthogonal modes bound by nonlinear couplings. Nevertheless, the influence of intermodal linear coupling on the physical properties of this bimodal structure remains to be decently revealed and harnessed. Utilizing an ultrafast fiber laser as a platform, we predict and demonstrate that the linear mode coupling (LMC) induces the deformable VS in terms of the temporal and spectral structures. Weak LMC supports heteronuclear vector solitons built of dissimilar polarization modes, i.e., a single pulse coupled to an orthogonal damped pulse chain. On the other hand, strong LMC facilitates the homonuclear VS composed of polarization modes with similar structures, in the form of soliton compounds featuring caterpillar motions. Our findings reveal new patterns of VSs and open an effective avenue for versatile ultrafast optical sources. - oai:arXiv.org:2512.10198v1 + Multi-messenger tracking of coherence loss during bond breaking + https://arxiv.org/abs/2512.16132 + arXiv:2512.16132v1 Announce Type: new +Abstract: Coupled electronic and nuclear motions govern chemical reactions, yet disentangling their interplay during bond rupture remains challenging. Here we follow the light-induced fragmentation of Br$_2$ using a coincidence-based multi-messenger approach. A UV pulse prepares the dissociative state, and strong-field ionization probes the evolving system. Coincident measurement of three-dimensional photoion and photoelectron momenta provides real-time access to both the instantaneous internuclear separation and the accompanying reorganization of the electronic structure, allowing us to determine the timescale of bond breaking. We find that electronic rearrangement concludes well before the nuclei reach the bond-breaking distance, revealing a hierarchy imposed by electron-nuclear coupling. Supported by semiclassical modelling, the results show that the stretched Br$_2$ molecule behaves as a two-centre interferometer in which the loss of coherence between atomic centres encodes the coupled evolution of electrons and nuclei. Our work establishes a general framework for imaging ultrafast electron-nuclear dynamics in molecules. + oai:arXiv.org:2512.16132v1 + physics.chem-ph + physics.atom-ph physics.optics - nlin.PS - Fri, 12 Dec 2025 00:00:00 -0500 + quant-ph + Fri, 19 Dec 2025 00:00:00 -0500 new - http://creativecommons.org/licenses/by/4.0/ - 10.1103/76cq-lrb6 - Du Yueqing, Zhang Zhenzhu, Zhang Heze, Xue Jia, Zeng Chao, Cui Yudong, Mao Dong, Malomed Boris, Zhao Jianlin + http://arxiv.org/licenses/nonexclusive-distrib/1.0/ + Tian Wang, Nida Haram, Zack Dube, Kyle A. Hamer, Yonghao Mi, Fatemeh Karimi, Andrei Yu. Naumov, Giulio Vampa, Caterina Vozzi, Xiaojun Liu, Albert Stolow, Michael Schuurman, Nicolas Douguet, David Villeneuve, Paul B. Corkum, Andre Staudte - Flow-priority optimization of additively manufactured variable-TPMS lattice heat exchanger based on macroscopic analysis - https://arxiv.org/abs/2512.10207 - arXiv:2512.10207v1 Announce Type: new -Abstract: Heat exchangers incorporating triply periodic minimal surface (TPMS) lattice structures have attracted considerable research interest because they promote uniform flow distribution, disrupt boundary layers, and improve convective heat-transfer performance. However, from the perspective of forming a macroscopic flow pattern optimized for heat-exchange efficiency, a uniform lattice is not necessarily the optimal configuration. This study initially presents a macroscopic modeling approach for a two-fluid heat exchanger equipped with a TPMS Primitive lattice. The macroscopic flow analysis is conducted based on the Darcy--Forchheimer theory. Under the assumption that heat is transferred solely at the interface between the fluid and the TPMS walls, a macroscopic heat-transfer model is developed using a volumetric heat-transfer coefficient, which serves as an artificial property characterizing the unit-volume heat-transfer capability. To regulate the relative dominance of the hot and cold flows-effectively, the channel widths-within the heat exchanger, we adopt the isosurface threshold of the Primitive lattice as the design variable and construct an optimization scheme for the lattice distribution using the previously described macroscopic model. The optimization is subsequently carried out for a planar heat exchanger where the hot and cold fluids each follow U-shaped flow trajectories. The optimal solution was verified, and its validity was examined through detailed geometric analysis and experiments conducted using metal LPBF. The optimal solution derived from the macroscopic model also demonstrated a clear performance advantage over the uniform lattice in the experimental results. The optimal solution obtained from the macroscopic model also demonstrated a clear performance improvement over the uniform lattice, with an average enhancement of 28.7% in the experimental results. - oai:arXiv.org:2512.10207v1 - physics.comp-ph + Intermittent Motility of a Synthetic Active Particle in Changing Environments + https://arxiv.org/abs/2512.16135 + arXiv:2512.16135v1 Announce Type: new +Abstract: We experimentally investigate the dynamics of synthetic active particles composed of gravitationally bouncing, superwalking droplets confined within an annular fluid bath. Driven by a topologically pumping dual-frequency waveform, the droplets exhibit alternating active (walking) and dormant (bouncing) phases, producing intermittent azimuthal motion. Tracking individual droplets reveals pseudolaminar chaotic dynamics in the time series of particle's angular position, characterized by laminar plateaus that are interrupted by short irregular bursts of activity. Increasing the driving amplitude induces a qualitative change in the active particle's intermittent dynamics, arising from a symmetry-breaking transition in its Faraday-wave field environment: continuous SO(2)-symmetric "channelling" waves give way to discrete "trapping" patterns. These findings demonstrate how environmental symmetry and spatiotemporal structure modulate motility and intermittency in synthetic active matter. + oai:arXiv.org:2512.16135v1 physics.flu-dyn - Fri, 12 Dec 2025 00:00:00 -0500 + cond-mat.soft + nlin.CD + nlin.PS + Fri, 19 Dec 2025 00:00:00 -0500 new - http://creativecommons.org/publicdomain/zero/1.0/ - Kazutaka Yanagihara, Jun Iwasaki, Kiyoto Saso, Taichi Yamashita, Shomu Murakoshi, Akihiro Takezawa + http://arxiv.org/licenses/nonexclusive-distrib/1.0/ + Rudra Sekhri, Rahil N. Valani, Tapio Simula - Search for a solar-bound axion halo using the Global Network of Optical Magnetometers for Exotic physics searches - https://arxiv.org/abs/2512.10221 - arXiv:2512.10221v1 Announce Type: new -Abstract: We report on a search for a gravitationally bound solar axion halo using data from the Global Network of Optical Magnetometers for Exotic physics searches (GNOME), a worldwide array of magnetically shielded atomic magnetometers with sensitivity to exotic spin couplings. Motivated by recent theoretical work suggesting that self-interacting ultralight axions can be captured by the Sun's gravitational field and thermalize into the ground state, we develop a signal model for the pseudo-magnetic fields generated by axion-proton gradient couplings in such a halo. The analysis focuses on the fifth GNOME Science Run (69 days, 12 stations), employing a cross-correlation pipeline with time-shifted daily modulation templates to search for the global, direction-dependent, monochromatic signal expected from a solar axion halo. No statistically significant candidate signals are observed. We set 95% confidence-level upper limits on the amplitude of the axion-induced pseudo-magnetic field over the frequency range 0.05 Hz to 20 Hz, translating to constraints on the linear and quadratic axion-proton couplings for halo densities predicted by gravitational capture models and for the maximum overdensities allowed by planetary ephemerides. In the quadratic coupling case, our limits surpass existing astrophysical bounds by over two orders of magnitude across much of the accessible parameter space. - oai:arXiv.org:2512.10221v1 - physics.atom-ph - quant-ph - Fri, 12 Dec 2025 00:00:00 -0500 + Predicting the Interfacial Energy and Morphology of DNA Condensates + https://arxiv.org/abs/2512.16150 + arXiv:2512.16150v1 Announce Type: new +Abstract: The physics and morphology of biomolecular condensates formed through liquid-liquid phase separation underpin diverse biological processes, exemplified by the nested organization of nucleoli that facilitates ribosome biogenesis. Here, we develop a theoretical and computational framework to understand and predict multiphase morphologies in DNA-nanostar solutions. Because morphology is governed by interfacial energies between coexisting phases, we combine Flory-Huggins theory with coarse-grained molecular dynamics simulations to examine how these energies depend on key microscopic features of DNA nanostars, including size, valence, bending rigidity, Debye screening length, binding strength, and sticky-end distribution. The phase behavior of DNA nanostars is quantitatively captured by a generalized lattice model, in which the interplay between sticky-end binding energy and conformational entropy determines the effective interactions. Focusing on condensates comprising two dense phases, we find that Janus-like morphologies are ubiquitous because the interfacial energies between the dense and dilute phases, $\gamma_{i\in\{1,2\}}$, are typically comparable. In contrast, nested morphologies are rare as they require a large asymmetry in $\gamma_i$, which arises only for highly dissimilar nanostars such as those differing markedly in valence or size. Moreover, the interfacial energy between the two dense phases, $\gamma_{12}$, can be modulated either discretely, by varying sticky-end distribution, or continuously, by tuning the crosslinker ratio; the former may even eliminate nested configurations. These findings establish physical design principles for constructing complex condensate architectures directly from microscopic molecular parameters. + oai:arXiv.org:2512.16150v1 + physics.bio-ph + cond-mat.soft + Fri, 19 Dec 2025 00:00:00 -0500 new - http://creativecommons.org/licenses/by/4.0/ - Tatum Z. Wilson, Derek F. Jackson Kimball, Samer Afach, Jiexiao Bi, B. C. Buchler, Dmitry Budker, Kaleb Cervantes, Joshua Eby, Nataniel L. Figueroa, Ron Folman, Jiawei Gao, Daniel Gavil\'an-Mart\'in, Menachem Givon, Zoran D. Gruji\'c, Hong Guo, Paul Hamilton, M. P. Hedges, Zhejun Huang, Dongok Kim, Younggeun Kim, Sami S. Khamis, Emmanuel Klinger, Abaz Kryemadhi, Nina Kukowski, Jianjun Li, Grzegorz Lukasiewicz, Hector Masia-Roig, Michal Padniuk, Christopher A. Palm, Chaitanya Paranjape, Sun Yool Park, Xiang Peng, Gilad Perez, Rayshaun Preston, Szymon Pustelny, Wolfram Ratzinger, Yossi Rosenzweig, Ophir M. Ruimi, Amy Saputo, Theo Scholtes, P. C. Segura, Yannis K. Semertzidis, Yun Chang Shin, Jason E. Stalnaker, Ibrahim Sulai, Dhruv Tandon, Ken Vu, Arne Wickenbrock, Teng Wu, Yucheng Yang, Yixin Zhao + http://arxiv.org/licenses/nonexclusive-distrib/1.0/ + Sihan Liu, Andrej Ko\v{s}mrlj - A DC discharge plasma experiment for undergraduate laboratories - https://arxiv.org/abs/2512.10259 - arXiv:2512.10259v1 Announce Type: new -Abstract: Plasma physics offers a wide range of fundamental phenomena, making it an excellent subject for undergraduate laboratory instruction. In this work, we present the design, construction, and characterization of a DC glow-discharge plasma chamber developed for the junior-level curriculum, a project carried out by two undergraduate students. The apparatus consists of a 1-meter-long quartz tube with a movable electrode, enabling systematic exploration of plasma behavior under varying pressure, voltage, and geometry. Using this platform, we characterized the Paschen breakdown relation and the voltage-current characteristics of the plasma. We then developed Langmuir probes to map spatial distributions of electron temperature and density, and used Boltzmann plot spectroscopy to measure excitation temperatures across different plasma regions. Finally, with custom Helmholtz coils, we demonstrated magnetic focusing of electrons. We performed Runge-Kutta simulations of particle trajectories and analyzed the electron drift velocity by comparing the focal lengths. Overall, this plasma chamber provides a versatile platform for investigating fundamental plasma phenomena and offers potential for future studies, including microwave-plasma interactions and other student-driven investigations. - oai:arXiv.org:2512.10259v1 + Toward the Origins of Binding Energy Shifts and Satellites Formation During Plasma-XPS Measurements + https://arxiv.org/abs/2512.16196 + arXiv:2512.16196v1 Announce Type: new +Abstract: In plasma X ray photoelectron spectroscopy emerges as a powerful platform for real time, in situ chemical analysis under conditions relevant to semiconductor processing and other plasma enabled technologies. This study investigates the origins of binding energy shifts and satellite peaks formation observed during plasma XPS measurements across conductive, dielectric, and gas phase systems. Using a standard laboratory based ambient pressure XPS apparatus coupled with an alternating current driven capacitively coupled plasma source, we show that metastable surface species, such as transient Au oxides, can be detected during plasma exposure, revealing chemical states hardly accessible using conventional ultrahigh vacuum XPS. In dielectric samples, we observe pressure- and plasma type dependent BE shifts up to 50 eV, attributed to X ray induced and plasma mediated surface charging. These shifts are mitigated at higher pressures plasmas or in electronegative plasmas, the latter due to enhanced charge compensation mechanisms involving slow negative ions. For gas phase species, AC plasma excitation leads to spectral broadening and the emergence of satellite peaks with a few eV energy separations, linked to oscillating local plasma potentials in the probing volume. These findings highlight the important and complex interplay of plasma parameters, surface charging, and local electric fields in shaping XPS spectra. Overall, plasma XPS emerges as a critical metrological tool for probing transient surface chemistry, with implications for semiconductor processing, material synthesis, and plasma diagnostics. + oai:arXiv.org:2512.16196v1 physics.plasm-ph - physics.ed-ph - Fri, 12 Dec 2025 00:00:00 -0500 + physics.ins-det + Fri, 19 Dec 2025 00:00:00 -0500 new - http://creativecommons.org/licenses/by/4.0/ - You-Hsuan Chen, Ting-An Wang, Pisin Chen + http://arxiv.org/licenses/nonexclusive-distrib/1.0/ + J. Trey Diulus, Ashley R. Head, Jorge Anibal Boscoboinik, Carles Corbella Roca, Alexander Tselev, Andrei Kolmakov - Techno-Economic Assessment of Wind-Powered Green Hydrogen Production for US Industrial Decarbonization - https://arxiv.org/abs/2512.10299 - arXiv:2512.10299v1 Announce Type: new -Abstract: This study evaluates the techno-economic feasibility of supplying industrial thermal loads with green hydrogen produced via water electrolysis using two pathways off-grid systems powered by co-located wind turbines and battery energy storage (BESS), and on-grid systems that procure electricity directly from the wind farm power node and operate electrolysers in response to real-time locational marginal prices (LMPs).The optimization results show that off-grid wind-to-hydrogen configurations in high-resource regions can achieve levelized costs of hydrogen (LCOH) on the order of \$7/kg, driven by high wind capacity factors and optimized BESS sizing that ensures operational continuity .Similarly in, on-grid, price-responsive operation achieves LCOH values of \$0.5/kg, reflecting sensitivity to electricity market volatility. Overall, the results suggest that Midwest wind-rich regions can support competitive green hydrogen production for industrial heat, with grid-connected electrolysers remaining attractive in locations with frequent low LMP periods. This dual-path analysis provides a transparent framework for industrial hydrogen deployment and highlights practical transition strategies for decarbonizing U.S. manufacturing. - oai:arXiv.org:2512.10299v1 - physics.soc-ph - physics.pop-ph - Fri, 12 Dec 2025 00:00:00 -0500 + Light matter interaction in van der Waals heterostructures with Mie voids + https://arxiv.org/abs/2512.16198 + arXiv:2512.16198v1 Announce Type: new +Abstract: Recently introduced concept of Mie voids allows to enhance the field localization inside air cavities embedded in high-index materials. Mie voids provide an alternative approach to conventional dielectric resonators that confine optical fields within bulk high-index materials. Building on this concept, here we present a hybrid photonic platform that integrates monolayer WS2 with Mie void resonators patterned in a high-index Bi2Te3 substrate. By carefully aligning the dipolar void resonance with the excitonic transition of WS2, we achieve substantially enhanced photoluminescence and second-harmonic generation. Far-field imaging of the harmonic fields reveals spatially resolved hotspots that directly map localized resonant modes, with their positions tunable by cavity geometry and pump wavelength. This approach enables real-space control of nonlinear emission at the single-resonator level, offering a robust and reconfigurable platform for next-generation nonlinear photonics and surface-enhanced optical sensing. + oai:arXiv.org:2512.16198v1 + physics.optics + Fri, 19 Dec 2025 00:00:00 -0500 + new + http://arxiv.org/licenses/nonexclusive-distrib/1.0/ + Zhuoyuan Lu, Kirill Koshelev, Pavel Tonkaev, Ziyu Chen, Dawei Liu, Wenkai Yang, Yuri Kivshar, Yuerui Lu + + + PASPT2: a novel size-extensive and size-consistent partial-active-space multi-state multi-reference second-order perturbation theory for strongly correlated electrons + https://arxiv.org/abs/2512.16212 + arXiv:2512.16212v1 Announce Type: new +Abstract: A partial-active-space (PAS) multi-state (MS) multi-reference second-order perturbation theory (MRPT2) for the electronic structure of strongly correlated systems of electrons, dubbed PASPT2, is formulated by linearizing the intermediate normalization-based general-model-space state-universal coupled-cluster theory with singles and doubles [IN-GMS-SU-CCSD; J. Chem. Phys. 119, 5320 (2003)]. At variance with the existence of disconnected terms in the IN-GMS-SU-CCSD amplitude equations, the disconnected terms in the PASPT2 amplitude equations can be avoided completely by choosing a special reference-specific zeroth-order Hamiltonian. The corresponding effective/intermediate Hamiltonian can also be made connected and closed, so as to render the energies obtained by diagonalization fully connected. As such, PASPT2 is strictly size-extensive, in sharp contrast with the parent IN-GMS-SU-CCSD. It is also size-consistent when the PAS of a supermolecule is chosen to be the direct product of those of the physically separated, non-interacting fragments. Prototypical systems are taken as showcases to reveal the efficacy of PASPT2. + oai:arXiv.org:2512.16212v1 + physics.chem-ph + Fri, 19 Dec 2025 00:00:00 -0500 new http://creativecommons.org/licenses/by/4.0/ - Bibish Chaulagain, Sanjeev Khanna + Chunzhang Liu, Ning Zhang, Wenjian Liu - Motifs in self-organising cells - https://arxiv.org/abs/2512.10307 - arXiv:2512.10307v1 Announce Type: new -Abstract: In complex systems, groups of interacting objects may form prevalent and persistent spatiotemporal patterns, which we refer to as motifs. These motifs can exhibit features that reveal how individual objects interact with one another. Simultaneously, the motifs can also interact, causing new coarse-grained properties to emerge in the system. - In this paper, we found motifs in a simulated system of Dynamically Self-Organising cells. We also found that quantifying these motifs with a set of physically interpretable structural and dynamic features efficiently captures the interaction dynamics of the motifs' underlying cells. Using these motif features, we revealed packing strain and defects in large compact aggregates, semi-periodicity in motif ensembles, and phase space classes with unsupervised machine learning. Additionally, we trained neural networks to infer the critical hidden microscopic interaction parameters within each motif from coarse-grained motif features extracted from snapshots of the system. Furthermore, we uncovered emergent features that can predict the movement of cell collectives by hierarchically coarse-graining smaller motifs into larger ones (e.g. motif clusters). We speculate that this concept of motif hierarchies may be applied broadly to many-body interacting systems that are otherwise too complex to understand. - oai:arXiv.org:2512.10307v1 - physics.bio-ph - Fri, 12 Dec 2025 00:00:00 -0500 + A unified MRT-LB framework for Navier-Stokes and nonlinear convection-diffusion equations and beyond: moment equations, auxiliary moments, multispeed lattices, and Hermite matrices + https://arxiv.org/abs/2512.16230 + arXiv:2512.16230v1 Announce Type: new +Abstract: We develop a unified multi-relaxation-time lattice Boltzmann (MRT-LB) framework based on discrete Hermite polynomials (Hermite matrices) for the Navier-Stokes equations (NSEs) and nonlinear convection-diffusion equations (NCDEs), using multispeed rectangular lattice (rD$d$Q$b$) models. For NSEs, the proposed MRT-LB model simulates incompressible and compressible isothermal flows in both single-phase and multiphase systems. Macroscopic moment equations are derived from the MRT-LB model via the direct Taylor expansion method. By selecting appropriate fundamental moments, the target NSEs and NCDE are recovered from these moment equations. Critically, the elimination of spurious terms and/or the recovery of the desired terms relies on specific auxiliary moments: the second-order auxiliary moment ($\mathbf{M}_{2G}$) of the source term distribution function (SDF) and the third-order auxiliary moment ($\mathbf{M}_{30}$) of the equilibrium distribution function (EDF) for NSEs, as well as the first-order auxiliary moment ($\mathbf{M}_{1G}$) of the SDF and the second-order auxiliary moment ($\mathbf{M}_{20}$) of the EDF for NCDE. Furthermore, using the weighted orthogonality of Hermite matrices, we establish essential relations for weight coefficients and construct several multispeed rectangular lattice models, including rD2Q25 and rD3Q53, with subgroup models rD2Q21, rD2Q17, rD2Q13, rD3Q45, and rD3Q33. A generalized third-order equilibrium distribution function is derived. We emphasize that for rectangular lattices, specific elements of the Hermite matrix corresponding to third-order discrete Hermite polynomials require correction to satisfy weighted orthogonality. + oai:arXiv.org:2512.16230v1 + physics.flu-dyn + physics.comp-ph + Fri, 19 Dec 2025 00:00:00 -0500 new - http://creativecommons.org/licenses/by-nc-nd/4.0/ - Ying Chen Lim, Rakesh Das, Tetsuya Hiraiwa, N. Duane Loh + http://arxiv.org/licenses/nonexclusive-distrib/1.0/ + Baochang Shi, Xiaolei Yuan, Zhenhua Chai - KRAS G12D protein screening for pancreatic cancer clinical trials using an AlGaN/GaN high electron mobility transistor biosensor - https://arxiv.org/abs/2512.10377 - arXiv:2512.10377v1 Announce Type: new -Abstract: Clinical trials screening KRAS G12D protein for 30 pancreatic ductal adenocarcinoma (PDAC) patients and 30 healthy donors were conducted utilizing an AlGaN/GaN high electron mobility transistor (HEMT) biosensor. All resistance change ratios of PDAC patients are higher than the standard deviation above the mean resistance change ratio obtained from all healthy donors. The results demonstrate the effectiveness of the HEMT biosensor and reveal its potential for early detection of pancreatic cancer with KRAS G12D protein screening. - oai:arXiv.org:2512.10377v1 - physics.med-ph - Fri, 12 Dec 2025 00:00:00 -0500 + Quantum Readiness in Latin American High Schools: Curriculum Compatibility and Enabling Conditions + https://arxiv.org/abs/2512.16257 + arXiv:2512.16257v1 Announce Type: new +Abstract: The accelerating global development of quantum technologies strengthens the case for introducing quantum computing concepts before university. Yet in Latin America, there is no consolidated, region wide integration of quantum computing into secondary education, and the feasibility conditions for doing so remain largely unexamined. This paper proposes a qualitative, comparative framework to assess academic readiness for quantum education across six countries - Peru, Bolivia, Chile, Argentina, Brazil, and Colombia - grounded in the relationship between curriculum compatibility and enabling conditions spanning institutional capacity, teacher preparation, infrastructure, and equity. Using official curricula, policy documents, national statistics, and educational reports, we apply structured qualitative coding and a 1-5 ordinal scoring system to generate a cross country diagnosis. The findings reveal substantial regional asymmetries: among the six countries studied, Chile emerges as the most institutionally prepared for progressive quantum education integration, while the remaining countries exhibit varying combinations of curricular gaps and fragmented but promising enabling conditions. Building on this diagnosis, we propose a country sensitive, regionally coordinated roadmap for staged implementation, beginning with teacher development and pilot centers, leveraging open source platforms and local language resources, and scaling toward gradual curricular integration. This work establishes a baseline for future quantitative and mixed method studies evaluating learning outcomes, motivation, and scalable models for quantum education in Latin America. + oai:arXiv.org:2512.16257v1 + physics.ed-ph + quant-ph + Fri, 19 Dec 2025 00:00:00 -0500 new http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Sheng-Ting Hung (Department of Physics, National Sun Yat-sen University, Kaohsiung, Taiwan), Cheng Yan Lee (Department of Physics, National Sun Yat-sen University, Kaohsiung, Taiwan), Chen-Yu Lien (Department of Physics, National Sun Yat-sen University, Kaohsiung, Taiwan), Cheng-Hsuan Chan (Department of Physics, National Sun Yat-sen University, Kaohsiung, Taiwan), Ya-Han Yang (Department of Surgery, Kaohsiung Medical University Hospital, Kaohsiung, Taiwan), Quark Yungsung Chen (Industry Academia Innovation School, National Yang Ming Chiao Tung University, Hsinchu, Taiwan, Department of Physics and Texas Center for Superconductivity, University of Houston, Houston, TX, USA), Kuang-Hung Cheng (Institute of Biomedical Sciences, National Sun Yat-sen University, Kaohsiung, Taiwan), Kung-Kai Kuo (Department of Surgery, Kaohsiung Medical University Hospital, Kaohsiung, Taiwan, Department of Surgery, E-DA Healthcare Group E-DA Dachang Hospital, Kaohsiung, Taiwan), Li-Wei Tu (Department of Physics, National Sun Yat-sen University, Kaohsiung, Taiwan), Ching-Wen Chang (Institute and Undergraduate Program of Electro-Optical Engineering, National Taiwan Normal University, Taipei, Taiwan) + Adriana Celeste Alvarado Leon, Osmar Denilson Herrera Cueva, Rosario Mercedes Morales Orvezo, Daniella Alexandra Crysti Vargas Saldana, Freddy Herrera Cueva - Generation of proton beams at switchback boundary-like rotational discontinuities in the solar wind - https://arxiv.org/abs/2512.10406 - arXiv:2512.10406v1 Announce Type: new -Abstract: Alfv\'enic rotational discontinuities (RDs) are abundant in the inner heliosphere and can be used to model the boundary of switchbacks, i.e. Alfv\'enic magnetic kinks. To investigate the effects of RDs on proton kinetics, we model a pair of switchback-boundary-like RDs with a hybrid Particle-In-Cell (PIC) approach in a 2D system. We find that, at one of the boundary RDs, a significant population of protons remains trapped over long times, creating a secondary beam-like component with temperature anisotropy $T_\perp/T_\|\gtrsim4$ in the proton velocity distribution function that excites ion cyclotron waves within the downstream portion of the transition layer. Further analysis suggests that the static electric field in the vicinity of the RD is the key factor in trapping the protons. This work indicates that switchback boundaries could represent a viable environment for the creation of proton beams in the heliosphere; it also highlights the need to investigate RD sub-structures, especially the embedded current systems of interplanetary RDs. Finally, this paper underscores the importance of high-resolution observations of the solar wind velocity distributions around RDs. - oai:arXiv.org:2512.10406v1 - physics.space-ph - astro-ph.SR - physics.plasm-ph - Fri, 12 Dec 2025 00:00:00 -0500 + Can Transformers overcome the lack of data in the simulation of history-dependent flows? + https://arxiv.org/abs/2512.16305 + arXiv:2512.16305v1 Announce Type: new +Abstract: It is well known that the lack of information about certain variables necessary for the description of a dynamical system leads to the introduction of historical dependence (lack of Markovian character of the model) and noise. Traditionally, scientists have made up for these shortcomings by designing phenomenological variables that take into account this historical dependence (typically, conformational tensors in fluids). Often, these phenomenological variables are not easily measurable experimentally. In this work, we study to what extent Transformer architectures are able to cope with the lack of experimental data on these variables. The methodology is evaluated on three benchmark problems: a cylinder flow with no history dependence, a viscoelastic Couette flow modeled via the Oldroyd-B formalism, and a non-linear polymeric fluid described by the FENE model. Our results show that the Transformer outperforms a thermodynamically consistent, structure-preserving neural network with metriplectic bias in systems with missing experimental data, providing lower errors even in low-dimensional latent spaces. In contrast, for systems whose state variables can be fully known, the metriplectic model achieves superior performance. + oai:arXiv.org:2512.16305v1 + physics.flu-dyn + cs.LG + Fri, 19 Dec 2025 00:00:00 -0500 new http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Rong Lin, Fabio Bacchini, Jiansen He, Luca Pezzini, Jingyu Peng + P. Urdeitx, I. Alfaro, D. Gonzalez, F. Chinesta, E. Cueto - Impact of Background Conditions on the Structure and Propagation of the Boreal Summer Quasi-Biweekly Oscillation - https://arxiv.org/abs/2512.10409 - arXiv:2512.10409v1 Announce Type: new -Abstract: We examine the westward-propagating quasi-biweekly oscillation (QBWO) during boreal summer, with a focus on how background moisture and winds shape its structure and propagation. In dry regions, convection lags the circulation by nearly a quarter cycle, whereas in very moist regions it becomes nearly in-phase and extends across the QBWO gyre. As the background moistens, moisture anomalies increasingly align with the QBWO circulation. Despite differences in environmental moisture and wind conditions, several structural features remain robust: outgoing longwave radiation and moisture anomalies stay collocated, moisture and pressure-velocity anomalies remain vertically upright, and the filtered winds retain a first-baroclinic mode structure. A vorticity budget shows that, although the planetary vorticity-gradient term is important, both planetary stretching and horizontal advection are needed to explain the vorticity tendency- and their relative importance shifts with the moisture regime. In dry and moderately moist regions with easterly mean flow, mean winds primarily advect vorticity anomalies. In contrast, in very moist regions with westerly flow, anomalous winds instead advect the background vorticity. An analogous transition occurs in the moisture budget: in dry and moderately moist environments, zonal mean flow advection dominates, but in very moist regions, strong background moisture gradients allow eddy advection of the mean moisture field to become the leading term. In the moist regime, vertical advection, precipitation, and evaporation also contribute substantially to the moisture tendency. Overall, the QBWO behaves like a mean-flow-driven linear mode in dry and moderately moist regions with easterly background winds, but shifts toward a regime dominated by eddy advection of background vorticity and moisture in very moist regions characterized by westerly flow. - oai:arXiv.org:2512.10409v1 - physics.ao-ph - Fri, 12 Dec 2025 00:00:00 -0500 + Polygonal Spatiotemporal Optical Vortices Wavepackets with Prescribed Vortex Structure + https://arxiv.org/abs/2512.16308 + arXiv:2512.16308v1 Announce Type: new +Abstract: Optical vortices carrying orbital angular momentum offer additional degrees of freedom. According to the orientation of orbital angular momentum, optical vortices can be classified into spatial optical vortex beam carrying longitudinalorbital angular momentum and spatiotemporal optical vortices carrying transverse orbital angular momentum. As an emerging subset of optical vortices, polygonal optical vortices provide a unique platform for a wide range of frontier applications by introducing a new degree of freedom in the form of a customizable intensity structure. In the spatial domain, polygonal spatial optical vortex beam carrying longitudinal orbital angular momentum have already demonstrated great potential in optical manipulation and two-photon lithography. However, polygonal spatiotemporal optical vortex wavepackets contain multiple sub spatiotemporal optical vortices carrying transverse orbital angular momentum remains unrealized to date. In this work, we theoretically propose and experimentally demonstrate polygonal spatiotemporal optical vortices wavepackets embedded with prescribed vortex structures. Within the structure, a prescribed number of sub spatiotemporal optical vortices carrying transverse orbital angular momentum is set along a designed polygonal spatiotemporal trajectory. Using the spatiotemporal holographic shaping approach, we generate polygonal perfect spatiotemporal optical vortex wavepacket and use the combination of multiple polygonal perfect spatiotemporal optical vortex wavepacket to form polygonal spatiotemporal optical vortex wavepacket with the prescribed vortex structure. A full control over multiple key properties of the polygonal spatiotemporal optical vortex wavepackets such as the geometry, number of phase singularities, and spatiotemporal distribution of sub spatiotemporal optical vortices is also achieved. + oai:arXiv.org:2512.16308v1 + physics.optics + Fri, 19 Dec 2025 00:00:00 -0500 + new + http://creativecommons.org/licenses/by/4.0/ + Haifa Fan, Qian Cao, Andy Chong, Qiwen Zhan + + + Bunch-by-Bunch Prediction of Beam Transverse Position, Phase, and Length in a Storage Ring Using Neural Networks + https://arxiv.org/abs/2512.16311 + arXiv:2512.16311v1 Announce Type: new +Abstract: Real-time, bunch-by-bunch monitoring of transverse position, longitudinal phase, and bunch length is crucial for beam control in diffraction-limited storage rings, where complex collective dynamics pose unprecedented diagnostic challenges. This study presents a neural network framework that simultaneously predicts these parameters directly from beam position monitor waveforms. The hybrid architecture integrates specialized Multi-Layer Perceptron (MLP), Convolutional Neural Network (CNN), and Long Short-Term Memory with Attention (LSTM-Attention) sub-networks, overcoming key limitations of traditional methods such as serial processing chains and batch-mode operation. Validated on experimental data from the Shanghai Synchrotron Radiation Facility and Hefei Light Source, the model achieves high prediction accuracy with a sub-millisecond latency of 0.042 ms per bunch. This performance demonstrates its potential as a core tool for real-time, multi-parameter diagnostics and active feedback in next-generation light sources. + oai:arXiv.org:2512.16311v1 + physics.acc-ph + Fri, 19 Dec 2025 00:00:00 -0500 new http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Shubhrangshu Biswas, Jai Sukhatme, Bishakhdatta Gayen + Can Liu, Xing Yang, Youming Deng, Qingqing Duan, Yongbin Leng - A Sampling Strategy Benchmark for Machine-Learning-Based Seismic Liquefaction Prediction - https://arxiv.org/abs/2512.10431 - arXiv:2512.10431v1 Announce Type: new -Abstract: Sampling strategy including sampling methods and training set configurations (training set sample size, train-test split ratio, and class distribution) significantly affects machine-learning (ML) model performance in seismic liquefaction prediction. However, existing ML applications in seismic liquefaction prediction remain fragmented: sampling strategies vary widely across studies without a unified benchmark. Moreover, these studies generally optimize the sample set configuration independently, ignoring the interaction among training set configurations. To address these limitations, this study establishes a benchmark that systematically evaluates sampling methods, training set sample sizes, train-test split ratios, class distributions, and training set configurations coupling on seven mainstream ML models performance, and further improves the predictive accuracy of seismic liquefaction-using a database of 250 historical liquefaction events, evaluated by Acc and F1. The results show that ordered systematic sampling yields the best performance across all models. The optimal model can be trained when the training set sample size is 200, the train-test split ratio is 80:20, and the class distribution range is 1-1.5. Among them, the train-test split ratio most significantly influenced performance, followed by the class distribution, with the training set sample size having the least effect. Furthermore, the Random Forest model achieves the highest performance, while the K-Nearest Neighbor model performs the weakest. Importantly, this study systematically identifies and verifies for the first time that there will be an interaction effect among training set configurations, rather than a simple additive effect. This study provides a benchmark for scholars to select the optimal sampling method and training set configurations to obtain high accuracy in ML-based liquefaction prediction. - oai:arXiv.org:2512.10431v1 - physics.geo-ph - Fri, 12 Dec 2025 00:00:00 -0500 + Three-Octave Supercontinuum Generation Spanning from Ultraviolet in Lithium Tantalate Waveguides + https://arxiv.org/abs/2512.16350 + arXiv:2512.16350v1 Announce Type: new +Abstract: We demonstrate, for the first time, supercontinuum generation spanning more than three octaves in dispersion-engineered thin-film lithium tantalite (TFLT) waveguides. Pumped by a femtosecond laser at 1560 nm, the waveguides yield a spectrum from 240 nm in the ultraviolet to beyond 2400 nm in the near-infrared. The spectral evolution is mapped from low-power harmonic generation (second- and third-harmonic) to a high-power continuum driven by soliton fission and dispersive wave emission. This first demonstration of ultrabroadband nonlinear optics in TFLT establishes it as a competitive, low-loss platform for integrated photonics, with significant potential for applications in frequency metrology and on-chip spectroscopy. + oai:arXiv.org:2512.16350v1 + physics.optics + Fri, 19 Dec 2025 00:00:00 -0500 new http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Jilei Hu, Fenglin He, Lianming Huang, Qianfeng Wang + Lingfang Wang, Tianyou Tang, Huizong Zhu, Juanjuan Lu - Coherent Source Subsampling: A Data-Driven Strategy for Restoring Causal-Acausal Symmetry in Ambient Seismic Wavefield Correlations - https://arxiv.org/abs/2512.10448 - arXiv:2512.10448v1 Announce Type: new -Abstract: Ambient noise tomography relies on the assumption that the seismic wavefield is equipartitioned, meaning that energy is uniformly distributed among all directions. However, in practice, ambient noise sources are highly non-uniform in both spatial and temporal dimensions, resulting in biased estimation of the Green's function between stations. We introduce a data-driven method, Coherent Source Subsampling (CSS), which selects and averages only those cross-correlation time windows that are associated with the excitation of sources in the stationary-zone. By confining the ensemble average to these coherent subsets, CSS effectively mitigates the influence of anisotropic or intermittent sources and restores causal-acausal symmetry in the retrieved Green's functions. Applications to regional-scale ambient noise datasets demonstrate that CSS boosts inter-station coherence and enhances the reliability of surface-wave dispersion measurements, providing a physically interpretable bridge between source statistics and noise correlation theory. - oai:arXiv.org:2512.10448v1 - physics.geo-ph - Fri, 12 Dec 2025 00:00:00 -0500 + Survey of Mathematical Models of and Numerical Methods for Fluid Dynamics Water Engineering + https://arxiv.org/abs/2512.16351 + arXiv:2512.16351v1 Announce Type: new +Abstract: Computational fluid dynamics (CFD) has become a cornerstone of modern water engineering, providing quantitative tools for the analysis, prediction, and management of complex hydraulic systems across a wide range of spatial and temporal scales. This survey reviews the mathematical models and numerical methods that underpin CFD applications in water engineering, from depth-averaged formulations such as the shallow water equations to fully three-dimensional Navier-Stokes models, as well as selected alternative modeling approaches. We examine the historical development of these models, their mathematical structure, and the numerical discretization and solution strategies commonly employed in practice, including finite difference, finite volume, and finite element methods. Beyond core solver technology, the survey addresses practical modeling issues such as source-term treatment, wetting and drying, turbulence modeling, free-surface representation, and computational efficiency. The growing role of data integration is also discussed, encompassing data assimilation, uncertainty quantification, and emerging machine-learning-assisted approaches that complement physics-based solvers. To illustrate the impact of modeling and numerical choices on real-world applications, representative case studies from large-scale water management systems are reviewed. By integrating theory, numerical techniques, and applied perspectives, this survey provides a unified reference for researchers and practitioners seeking to understand both the foundational principles and contemporary challenges of CFD in water engineering. + oai:arXiv.org:2512.16351v1 + physics.flu-dyn + Fri, 19 Dec 2025 00:00:00 -0500 new http://creativecommons.org/licenses/by/4.0/ - Sanket Narayan Bajad, Pawan Bharadwaj + Anshu Kumar, Kemi Olimba, Vyacheslav Kungurtsev, Fabio V. Difonzo - An Extended Mixed Quantum/Classical Approach for Quantitative Calculation of Complex Refractive Index - https://arxiv.org/abs/2512.10454 - arXiv:2512.10454v1 Announce Type: new -Abstract: The mixed quantum/classical approach of Skinner and co-workers has been widely used to calculate the line shapes of the infrared spectra of water (H2O), but less attention has been paid to the use of this approach in quantitatively calculating spectral intensity, thereby limiting direct comparisons of calculated and experimental spectra. Here, we extend this theoretical framework to facilitate direct computation of the full complex refractive index of water, replacing the normalized ordinate used in previous studies. Our results for the OH stretching region of H2O capture both the shapes and intensities of the experimental spectra. They reveal that inclusion of the local field effect is crucial to the accurate reproduction of spectral intensity. This extended approach enables new areas of analysis of the bulk, thin-film, and cluster spectra of water. - oai:arXiv.org:2512.10454v1 - physics.optics - physics.chem-ph - Fri, 12 Dec 2025 00:00:00 -0500 + Back with Weight: Revisiting Very Heavy Ions for Precision Radiotherapy + https://arxiv.org/abs/2512.16355 + arXiv:2512.16355v1 Announce Type: new +Abstract: Accelerated charged particles offer significant physical advantages over X-rays in radiotherapy. In addition to their superior depth-dose distribution, heavy ions provide notable biological benefits compared to protons. Specifically, at therapeutic energies, very heavy ions are expected to exhibit high relative biological effectiveness and a low oxygen enhancement ratio, making them potentially ideal for treating radioresistant tumors. Over fifty years ago, the Lawrence Berkeley Laboratory started a clinical trial to treat cancer patients with particles ranging from helium to argon. However, treatments with ions of atomic number greater than 10 proved highly toxic to normal tissue. Most patients were ultimately treated with helium ions, whose biological effects closely resemble those of protons. In recent years, novel strategies have emerged that can reduce normal tissue toxicity in radiotherapy while preserving tumor control. These advancements open the possibility of revisiting the clinical use of heavier ions. In this paper, we propose that neon ions may serve as an effective modality for treating resistant, hypoxic tumors. Their associated toxicity may be mitigated by employing approaches such as ultra-high dose rate (FLASH) or spatially fractionated radiotherapy. Current plans and prospects for the clinical application of neon ions will be discussed. + oai:arXiv.org:2512.16355v1 + physics.med-ph + physics.bio-ph + Fri, 19 Dec 2025 00:00:00 -0500 new http://creativecommons.org/licenses/by/4.0/ - 10.1021/acs.jpclett.5c02887 - J. Phys. Chem. Lett. 2025, 16, XXX, 12741-12751 - Ian F. Mochida, Tetsuyuki Takayama, Shoichi Yamaguchi, Tetsuya Hama + Jeannette Jansen, Olga Sokol, Yolanda Prezado, Marco Durante - Pockels effect induced strong Kerr nonlinearity in a lithium niobate waveguide - https://arxiv.org/abs/2512.10462 - arXiv:2512.10462v1 Announce Type: new -Abstract: The utilization of Kerr nonlinearity in lithium niobate has been extensively investigated over the years. Nevertheless, the practical implementation of Kerr nonlinearity in waveguides has been constrained by the material's inherently low third-order nonlinear coefficients. Here, we present a significant advancement by demonstrating Pockels effect-induced strong Kerr nonlinearity in a periodically poled thin-film lithium niobate waveguide. Both effective four-wave mixing (FWM) and cascaded effective FWM processes are experimentally observed. The induced FWM process achieves a remarkable maximum output power of -8.5 dBm, spanning a wavelength spectrum of over 116.8 nm. Analysis reveals that the induced effective Kerr nonlinearity exhibits a substantial effective nonlinear refractive index as $2.9\times 10^{-15} m^{2}W^{-1}$, corresponding to an effective nonlinear refractive index enhancement factor of $1.6\times 10^{4}$ relative to the intrinsic value. Moreover, a wavelength-converting experiment demonstrates a flat optic-to-optic response over a broadband radiofrequency spectrum, confirming that signal integrity is well preserved after on-chip effective FWM conversion. Therefore, the demonstrated efficient and broadband Pockels effect induced effective Kerr nonlinearity paves the way for novel applications in diverse fields, including spectroscopy, parametric amplification, quantum correlation studies, and wavelength conversion technologies. - oai:arXiv.org:2512.10462v1 - physics.optics - Fri, 12 Dec 2025 00:00:00 -0500 + Marangoni instabilities of cylindrical drops in a vertical Hele-Shaw cell immersed in stratified liquids + https://arxiv.org/abs/2512.16388 + arXiv:2512.16388v1 Announce Type: new +Abstract: The Marangoni instability of cylindrical drops in vertical Hele-Shaw cells immersed in stably stratified liquids has been studied previously, yet the underlying mechanism has not been explored thoroughly. Here we study the onset of the Marangoni instability of such a system by experimentally explore the parameter space of the drop radius and concentration gradient. The concentration field is directly observed with laser interferometry. The flow is found to become unstable when advection is too strong for diffusion to maintain a stable concentration field. However, two different instability regimes are found depending on the drop radius. When the drop is small, the friction force caused by the two plates of the Hele-Shaw cell is small so that it does not change much the velocity field. Marangoni advection in such a regime can be very strong so that the entire periphery of the drop can become unstable. When the drop is large, the friction becomes so large that the Marangoni velocity plateaus and the boundary layer thickness is also reduced. The modified velocity and concentration fields lead to another instability regime, where only liquid close to the equator of the drop becomes unstable. A unifying scaling theory that includes both instability regimes is developed, which agrees well with the experimental results. Our findings may shed new light on the understandings of Marangoni flows in confined geometries. + oai:arXiv.org:2512.16388v1 + physics.flu-dyn + Fri, 19 Dec 2025 00:00:00 -0500 new - http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Haoran Li, Fei Huang, Jingyan Guo, He Gao, Hanwen Li, Zhile Wu, Xinmin Yao, Zhengyuan Bao, Huan Li, Yaocheng Shi, Zejie Yu, Daoxin Dai + http://creativecommons.org/licenses/by-nc-sa/4.0/ + Li-Chen Huang, Yanshen Li - Identification and Characterization of the Topside Bulge of the Venusian Ionosphere - https://arxiv.org/abs/2512.10464 - arXiv:2512.10464v1 Announce Type: new -Abstract: Venus, in the absence of an intrinsic magnetic field, undergoes a direct interaction between its ionosphere and the solar wind. Previous missions, including Mariner, Venera, and the Pioneer Venus Orbiter (PVO), reported a recurring localized increase in electron density, often termed a "bulge," at altitudes between 160 and 200 km. This study investigates this topside bulge using over 200 dayside electron density profiles derived from the Venus Radio Science experiment (VeRa) onboard the Venus Express (VEX). We employ an automated, gradient-based classification algorithm to provide a quantitative and reproducible method for identifying and categorizing the bulge morphology into three types. Type 1 profiles exhibit a distinct secondary peak above the main V2 layer. Type 2 profiles display a shoulder-like feature near the bulge altitude. Type 3 bulges are not visually apparent but can be identified through residuals obtained after subtracting a Chapman layer fit to the V2 peak. The bulge is detected in over 80\% of the analyzed profiles, with a higher occurrence during periods of low solar activity and at lower solar zenith angles (SZA). Type 1 morphologies are only observed at low latitudes (within $\pm 40^\circ$). The peak altitude of the bulge negatively correlates with SZA, suggesting that thermospheric cooling toward the terminator significantly influences the bulge altitude. The occurrence patterns and morphological characteristics indicate that the bulge is likely influenced by external drivers, such as solar wind interaction, rather than being solely a result of local photochemical processes. - oai:arXiv.org:2512.10464v1 - physics.space-ph - astro-ph.EP - Fri, 12 Dec 2025 00:00:00 -0500 + What defines a group of friends? Rethinking community structure in signed, directed networks + https://arxiv.org/abs/2512.16399 + arXiv:2512.16399v1 Announce Type: new +Abstract: We study the structure of personal relationships among 1068 high school students using a dataset that contains the network of self-reported friendly and conflictive relationships, with information on their directionality and intensity. We analyse the resulting weighted, directed, and signed network using a Bayesian stochastic block model framework, which enables the inference of group structure without imposing prior assumptions on the role of negative or asymmetric ties. While a full model incorporating all edge attributes yields statistically coherent clusters, these do not align with socially meaningful communities. To address this, we focus first on the network backbone of mutual affinities, and we characterize its group organization. Many communities display an assortative structure, often embedded within larger cohesive configurations, but we also observe more diverse patterns such as core-periphery structure and isolated nodes. We then examine how relationship intensity, directionality, and conflict shape group structure. Asymmetric ties, though often occurring between communities, are frequently present within them, revealing the stabilizing effect of group membership on non-mutual relationships. Furthermore, the presence of asymmetric ties does not inherently imply a hierarchical structure, given that all groups both receive and report significant levels of non-reciprocal ties. More intense ties play a disproportionate role in shaping community structure. Finally, negative ties tend to bridge communities, but we find that groups feature a significant level of internal conflict. Our research offers a new perspective on the study of group organization when rich information about the directionality, the intensity and the sign of ties is considered, with implications for identifying social vulnerability and designing targeted interventions. + oai:arXiv.org:2512.16399v1 + physics.soc-ph + Fri, 19 Dec 2025 00:00:00 -0500 + new + http://creativecommons.org/licenses/by-nc-nd/4.0/ + Miguel A. Gonz\'alez-Casado, Angel S\'anchez, Santo Fortunato + + + Photoacoustic model for laser-induced acoustic desorption of nanoparticles + https://arxiv.org/abs/2512.16403 + arXiv:2512.16403v1 Announce Type: new +Abstract: Laser-induced acoustic desorption (LIAD) enables loading nanoparticles into optical traps under vacuum for levitated optomechanics experiments. Current LIAD systems rely on empirical optimization using available laboratory lasers rather than systematic theoretical design, resulting in large systems incompatible with portable or space-based applications. We develop a theoretical framework using the photoacoustic wave equation to model acoustic wave generation and propagation in metal substrates, enabling systematic optimization of laser parameters. The model identifies key scaling relationships: surface acceleration scales as $\tau^{-2}$ with pulse duration, while acoustic diffraction sets fundamental limits on optimal spot size $w \gtrsim \sqrt{v\tau d}$. Material figures of merit combine thermal expansion and optical absorption properties, suggesting alternatives to traditional aluminum substrates. The framework validates well against experimental data and demonstrates that compact laser systems with sub-nanosecond pulse durations can achieve performance competitive with existing laboratory-scale implementations despite orders-of-magnitude lower pulse energies. This enables rational design of minimal LIAD systems for practical applications. + oai:arXiv.org:2512.16403v1 + physics.optics + quant-ph + Fri, 19 Dec 2025 00:00:00 -0500 new http://creativecommons.org/licenses/by/4.0/ - Satyandra M. Sharma, Varun Sheel, Martin P\"atzold + Matthew Edmonds, James Bateman - Classical Dirac particle: Mass and Spin invariance and radiation reaction - https://arxiv.org/abs/2512.10505 - arXiv:2512.10505v1 Announce Type: new -Abstract: According to the atomic principle an elementary particle has no excited states and under any interaction, if it is not annihilated, its internal structure cannot be modified. The intrinsic properties are the mass $m$ and the absolute value of the spin in the center of mass frame $S=\hbar/2$. We analyze the closed system made of a single Dirac particle and an external electromagnetic field. The Poincar\'e invariance of the dynamics implies that the energy, linear momentum and angular momentum of the whole system must be conserved. The Dirac particle has two distinguished points, the center of charge ${\bf r}$ and the center of mass ${\bf q}$. When interacting, the energy expended by the field is the work done by the external Lorentz force along the center of charge trajectory. The variation of the mechanical energy of the particle is the work done by the external Lorentz force along the center of mass trajectory. If these two works are different the excess of energy must be transformed into radiation returning that energy to the field. The accelerated Dirac particle radiates. We analyze the spin dynamics of the Dirac particle under an external electromagnetic field. The requirement that the absolute value of the spin for the center of mass observer cannot be modified by the interaction implies a modification of the dynamical equation which includes a new braking term along the center of mass velocity, that can be interpreted as the radiation reaction force. - oai:arXiv.org:2512.10505v1 - physics.class-ph - Fri, 12 Dec 2025 00:00:00 -0500 + Topological reorganization of near-field energy flow governing scattering transitions in subwavelength rectangular grooves + https://arxiv.org/abs/2512.16407 + arXiv:2512.16407v1 Announce Type: new +Abstract: The scattering of electromagnetic waves by subwavelength rectangular grooves has been extensively studied, yet its physical interpretation has largely relied on field-intensity distri- butions. Here we demonstrate that the transition from concave to convex scattering profiles observed as the groove width approaches the wavelength is governed by a topological reorga- nization of the near-field energy flow. Using a rigorous modal formulation for TM-polarized fields, we analyze the complex electromagnetic field and the associated time-averaged Poynt- ing vector. We show that reducing the groove width induces the creation, migration, and annihilation of Poynting-vector singularities, including vortices and saddle points, leading to a qualitative restructuring of electromagnetic energy transport. This topological transition redirects the local energy flux and manifests as a convex scattering profile in the far field. The results establish a direct link between near-field energy topology and far-field scattering, providing a unified physical interpretation of subwavelength groove scattering. + oai:arXiv.org:2512.16407v1 + physics.optics + Fri, 19 Dec 2025 00:00:00 -0500 new http://creativecommons.org/licenses/by/4.0/ - Martin Rivas + J. Sumaya-Martinez, J. Mulia-Rodriguez - Rapid all-optical loading of trapped ions using a miniaturised atom source - https://arxiv.org/abs/2512.10514 - arXiv:2512.10514v1 Announce Type: new -Abstract: We characterise an efficient optically-heated neutral atom source for ion trapping. We observe loading rates of up to $24(3)\,\mathrm{s}^{-1}$ with heating powers below $85\,\mathrm{mW}$, and demonstrate loading of a single ion in under $30\,\mathrm{s}$ with $41.4(4)\,\mathrm{mW}$ of optical power in a room-temperature ion trap system with an ionisation probability of $1.50(5)\times10^{-5}$. We calibrate a thermal model for the source's internal temperature by imaging the fluorescence of a collimated flux of neutral calcium that effuses from the oven at various optical heating powers. We show that the thermal performance of this oven is mainly limited by radiative losses. We explore the effect of second-stage photo-ionisation laser power on the loading rate, and identify a path beyond the loading rates reported in this study. We predict that this source is also well-suited to a wide range of metals used in ion-trapping. - oai:arXiv.org:2512.10514v1 + Calculation of hyperfine structure in Tm \textsc{ii} + https://arxiv.org/abs/2512.16426 + arXiv:2512.16426v1 Announce Type: new +Abstract: The first measurements of the magnetic dipole hyperfine structure constants A in singly ionized thulium revealed substantial discrepancies with the corresponding calculations [Mansour et al., NIMB \textbf{40}, 252 (1989)]. More recent measurements [Kebapc{\i} et al., ApJ \textbf{970}, 23 (2024)] expanded very limited dataset of that work and demonstrated that two of the previously reported experimental A values were incorrect, motivating new theoretical calculations. In this work, we employ the configuration interaction method to calculate the A constants for several low-lying levels in Tm II, with the random-phase-approximation corrections also taken into account. Our results show good agreement with the new experimental data and provide reliable predictions for additional states where measurements are not yet available. + oai:arXiv.org:2512.16426v1 physics.atom-ph - quant-ph - Fri, 12 Dec 2025 00:00:00 -0500 + Fri, 19 Dec 2025 00:00:00 -0500 new http://creativecommons.org/licenses/by/4.0/ - Lorenzo Versini, Tim F. Wohlers-Reichel, Catherine E. J. Challoner, Thomas Hinde, Arjun D. Rao, William J. Hughes, Peter Drmota, Thomas H. Doherty, Laurent J. Stephenson, Jacob A. Blackmore, Joseph F. Goodwin + Andrey I. Bondarev - Ultra-Fast Muon Transport via Histogram Sampling on GPUs - https://arxiv.org/abs/2512.10520 - arXiv:2512.10520v1 Announce Type: new -Abstract: We present a GPU-accelerated method for muon transport based on histogram sampling that delivers orders of magnitude faster performance than CPU-based Geant4 simulation. Our method employs precomputed histograms of momentum loss and scattering, derived from detailed Geant4 simulations, to statistically reproduce all the non-decaying physics processes during muon traversal through matter. Implemented as a CUDA kernel, the parallel algorithm enables the concurrent simulation of tens of thousands of particles on a single GPU whilst taking into account a complex geometry and a magnetic field force integrated using a fourth-order Runge-Kutta method. Validation against Geant4 in both simple and realistic detector geometries shows that the approach preserves key physical features while achieving speedups of several orders of magnitude, even compared to CPU-based simulations on a large CPU farm with over a thousand cores. This work highlights the significant potential of GPU-based implementations for particle transport, with applicability extending to neutrino propagation and future implementations including discrete processes such as particle decay. - oai:arXiv.org:2512.10520v1 - physics.comp-ph - Fri, 12 Dec 2025 00:00:00 -0500 + Reconfigurable Silicon Photonics Extreme Learning Machine with Random Non-linearities as Neural Processor and Physical Unclonable Function + https://arxiv.org/abs/2512.16467 + arXiv:2512.16467v1 Announce Type: new +Abstract: An alternative extreme learning machine -ELM- paradigm is presented exploiting random non-linearities -RN, named RN-ELM, instead of a conventional fixed node non-linearity. This method is implemented on a hybrid neural engine, with the physical layer realized by an integrated silicon photonic mesh and the digital layer by a simple regression algorithm. Non-linearities are intrinsically non-power depended and are generated through non-linear frequency to power mapping offered by optical filters. The numerical evaluation is based on an experimentally derived transfer function of an all-pass filter, implemented on a silicon reconfigurable photonic integrated chip -RPIC. RN-ELM is evaluated in a twofold manner; first as a machine learning scheme, where the expressivity offered by multiple, yet random, activation functions lead to a compact and highly simplified design with 5 optical filters, offering state-of-the-art performance in time-series prediction tasks with minimum hardware requirements. The second scenario entails its deployment as a physical unclonable function -PUF, for authentication applications directly in the physical layer. In this case, the random activation functions are associated with unavoidable, fabrication related waveguide imperfections that can act as hardware signatures. Numerical results reveal a probability of cloning as low as 10e-15, which corresponds to a highly secure authentication token. + oai:arXiv.org:2512.16467v1 + physics.optics + eess.SP + Fri, 19 Dec 2025 00:00:00 -0500 new - http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Luis Felipe P. Cattelan, Shah Rukh Qasim, Patrick H. Owen, Nicola Serra + http://creativecommons.org/licenses/by/4.0/ + George Sarantoglou, Georgios Aias Karydis, Adonis Bogris, Charis Mesaritakis - Convective and non-convective nature of Balearic meteotsunamis:a 50-year historical review - https://arxiv.org/abs/2512.10535 - arXiv:2512.10535v1 Announce Type: new -Abstract: Meteotsunamis, locally known as rissaga in the Balearic Islands, are significant sea-level oscillations induced by atmospheric disturbances, with amplitudes and frequencies comparable to seismic tsunamis. The port of Ciutadella (Menorca), is a recognized hotspot for meteotsunami occurrence. This study presents a 50-year analysis of 191 meteotsunami events recorded in Ciutadella between 1975 and 2025, focusing on the distinction between the convective and non-convective nature of the pressure disturbances that triggered the meteotsunami event and their implications for predictability and risk assessment. Events were classified using historical records, in-situ barographic and sea-level observations, satellite imagery, and lightning data. Results show that non-convective meteotsunamis are typically triggered by internal gravity waves, producing relatively regular and moderate pressure fluctuations. In contrast, convective events are associated with abrupt pressure jumps and tend to produce the most extreme sea-level oscillations, exceeding 3-4 meters in some cases, such as the catastrophic events of June 1984 and June 2006. Forecasting skill varied by event type: A full-realistic high-resolution ocean-atmosphere modelling system (BRIFS) performed better for convective cases, whereas a targeted reduced-physics method (TRAM) was more accurate for non-convective scenarios. This study provides the most extensive meteotsunami dataset for the Balearic Islands to date and offers a novel framework for understanding the contrasting dynamics and characteristics of both types of events. The results support the development of improved early-warning systems and more effective coastal risk mitigation strategies in vulnerable regions. - oai:arXiv.org:2512.10535v1 - physics.ao-ph - Fri, 12 Dec 2025 00:00:00 -0500 + An epsilon-near-zero-based nonlinear platform for ultrafast re-writable holography + https://arxiv.org/abs/2512.16471 + arXiv:2512.16471v1 Announce Type: new +Abstract: We re-examine real-time holography for all-optical structuring of light and optical computation using a contemporary material: a subwavelength-thick, spatially unstructured film of indium tin oxide (ITO). When excited by spatially structured light at epsilon-near-zero frequencies, the film acts as an efficient and reconfigurable diffractive optical platform for all-optical modulation of light such as spatial structuring and optical computations. We demonstrate a few percent of absolute diffraction efficiency over greater than 300 nm bandwidth around telecom wavelengths using a film four orders of magnitude thinner than and up to six orders of magnitude faster than standard holographic materials. Our findings highlight the potential of using epsilon-near-zero-based nanostructures for efficient modulation of spatially structured light and rapid prototyping without complex nanofabrication processes. + oai:arXiv.org:2512.16471v1 + physics.optics + Fri, 19 Dec 2025 00:00:00 -0500 new http://creativecommons.org/licenses/by/4.0/ - Agust\'i Jans\`a, Diego S. Carri\'o, Camilo Melo, Romualdo Romero, Baptiste Mourre, V\'ictor Homar + M. Zahirul Alam, Robert Fickler, Yiyu Zhou, Enno Giese, Jeremy Upham, Robert W. Boyd - Event-sparse stack denoising for 4D-STEM applications - https://arxiv.org/abs/2512.10555 - arXiv:2512.10555v1 Announce Type: new -Abstract: We introduce a denoising method for four-dimensional scanning transmission electron microscopy (4D-STEM) that relies on processing local, scan position-independent electron event-sparse data stacks, called event-sparse stack denoising. This method adds an extra time dimension during data collection by recording multiple electron event-sparse diffraction patterns. The resulting datasets are effectively five-dimensional, referred to as locally time-resolved STEM (LTR-STEM). Diffraction data stacks at each scan position are processed using one of two sparsity denoising pipelines: 1) the density-based spatial clustering of applications with noise (DBSCAN) algorithm followed by multi-step persistence thresholding, or 2) sparse principal component analysis (sparse PCA), followed by single-step thresholding. Both methods perform well for diffraction data denoising, as shown by simulated peak signal-to-noise ratio (PSNR) curves, denoised experimental data for virtual imaging, and application-specific denoising for defect detection. PSNR analysis indicates that sparsity-denoised 4D-STEM data reaches the same PSNR as raw data at approximately 16% of the exposure time, demonstrating comparable image quality with a lower dose. In defect detection, a 4.1x increase in sensitivity to relative radial disk shift is observed in the denoised data. Moreover, the LTR-STEM technique may be used to inspect material degradation by tracking changes in diffraction disk intensity, allowing for critical dose estimation and exposure-selective imaging. - oai:arXiv.org:2512.10555v1 + Endorsing Titanium-Scandium Radionuclide Generator for PET and Positronium Imaging + https://arxiv.org/abs/2512.16508 + arXiv:2512.16508v1 Announce Type: new +Abstract: The development of PET and positronium imaging techniques is strictly related to the availability of suitable radionuclides and robust radiochemistry platforms. Among the emerging candidates, $^{44}$Sc has attracted significant interest due to its favourable physical properties, including a half-life of $\sim$4 hours, a pure $\beta^{+}$ emission profile, and the additional prompt $\gamma$-emission that enables advanced triple-photon detection schemes. These characteristics make $^{44}$Sc particularly promising for highresolution imaging and novel quantitative methodologies. However, routine clinical and preclinical implementation requires a practical, sustainable, and cost-efficient production route. In this context, we propose a titanium-scandium radionuclide generator as an optimal solution. This study focuses on optimising the synthesis of the long-lived parent isotope, $^{44}$Ti ($T_{1/2}$ = 59.1 years), from which $^{44}$Sc can be selectively eluted in a chemically pure form when needed. An analysis of various production pathways was conducted, including proton and deuteron reactions on scandium, as well as $\alpha$-particle and lithium-induced reactions on calcium, to determine the most efficient reaction parameters, target design, and expected yield. Furthermore, we identify some existing cyclotron facilities suitable for implementing this technology. Results indicate that efficient $^{44}$Ti production is achievable using proton beams in the 20-30 MeV range under extended irradiation conditions. The proposed generator system would enable routine and decentralised $^{44}$Sc supply. Its integration with the novel J-PET scanner may significantly reduce diagnostic costs and improve access to advanced PET imaging in regions with limited medical imaging infrastructure. + oai:arXiv.org:2512.16508v1 physics.med-ph - cond-mat.other - Fri, 12 Dec 2025 00:00:00 -0500 + Fri, 19 Dec 2025 00:00:00 -0500 new - http://creativecommons.org/licenses/by/4.0/ - Gregory Nordahl, Rebekka Klemmt, Espen Drath B{\o}jesen + http://creativecommons.org/licenses/by-nc-nd/4.0/ + Pawe{\l} Moskal, Aleksander Khreptak, Jaros{\l}aw Choi\'nski, Pete Jones, Ihor Kadenko, Agnieszka Majkowska-Pilip, Rudrajyoti Palit, Anna Stolarz, Rafa{\l} Walczak, Ewa St\k{e}pie\'n - Coupling opinion dynamics and epidemiology - https://arxiv.org/abs/2512.10612 - arXiv:2512.10612v1 Announce Type: new -Abstract: This research investigates the coupled dynamics of behavior and infectious disease using a mathematical model. We integrate a two-state q-voter opinion process with SIS-type infection dynamics, where transmission rates are influenced by the opinion and an infection-induced switching mechanism represents individuals reassessing their behav- ior upon infection. Analytically, we derive conditions for the stability of endemic and disease-free equilibria. Numerical simulations reveal complex dynamics: above a certain infectivity threshold, the system can exhibit alternative basins of attraction leading to a balanced endemic fixed point or stable limit cycles. Notably, the dominant asymptotic opinion and resulting epidemiological outcomes show non-monotonic relationships with infectivity, highlighting the potential for adaptive behavior to induce complex system dynamics. These findings underscore the critical role of social interventions; shifts in behavioral norms and trust can permanently alter epidemic outcomes, suggesting that such interventions are as crucial as biomedical controls - oai:arXiv.org:2512.10612v1 - physics.soc-ph - math.DS - q-bio.PE - Fri, 12 Dec 2025 00:00:00 -0500 + Spatiotemporal topological phase transitions in photonic spacetime crystals + https://arxiv.org/abs/2512.16516 + arXiv:2512.16516v1 Announce Type: new +Abstract: Topological phase transitions, characterized by the closing and reopening of band gaps and a concomitant change in topological invariants, have played a central role in topological physics. However, such transitions have so far been restricted to spatial crystals, relying solely on energy band gaps and spatial interfaces. Here, we transcend this conventional framework and report, for the first time, spatiotemporal topological phase transition in photonic spacetime crystals - structures that are periodically modulated in both space and time. Using a dynamically modulated transmission line metamaterial, we theoretically propose and experimentally demonstrate complete spatiotemporal topological phase transitions characterized by the closing and reopening of both energy and momentum band gaps, alongside changes in spatiotemporal topological invariants and topological phases. Furthermore, in a genuine photonic spacetime crystal that possesses a complete energy-momentum band gap, we directly observe a space-time topological event that localizes in both space and time, exhibiting relativistic-causality-governed excitation and robustness against spatiotemporal disorders. Our findings reveal the interplay among space, time, and topology, establishing a unified framework that provides a comprehensive picture of the emerging topological space-time physics and opening new avenues for robust spatiotemporal topological wave manipulations. + oai:arXiv.org:2512.16516v1 + physics.optics + Fri, 19 Dec 2025 00:00:00 -0500 new - http://creativecommons.org/licenses/by-sa/4.0/ - Thomas Goetz, Tyll Krueger, Karol Niedzielewski, Jan Schneider, Barbara Pabjan + http://arxiv.org/licenses/nonexclusive-distrib/1.0/ + Zebin Zhu, Bolun Huang, Siqi Xu, Jingming Chen, Yan Meng, Zhenxiao Zhu, Xiang Xi, Zhen Gao - Generating wall-bounded turbulent inflows at high Reynolds numbers - https://arxiv.org/abs/2512.10623 - arXiv:2512.10623v1 Announce Type: new -Abstract: One of the main challenges in simulating high Reynolds number ($Re$) turbulent boundary layers (TBLs) is the long streamwise distance required for large-scale outer-layer structures to develop, making such simulations prohibitively expensive. We propose an inflow generation method for high $Re$ wall turbulence that leverages the known structure and scaling laws of TBLs, enabling shorter development lengths by providing rich input information. As observed from the inner-scaled pre-multiplied spectra of streamwise velocity, with an increase in $Re$ the outer region grows and occupies more of the spanwise wavenumber space in proportion to the increase in $Re$; while the inner region remains approximately the same. Exploiting this behavior, we generate high-$Re$ inflow conditions for a $\textit{target}$ $Re$ by starting from cross-stream velocity slices at a lower $\textit{base}$ $Re$. In spectral space, we identify the inner and outer region wavenumbers, and shift the outer-region components proportionally to the desired $Re$ increase. We closely examine the capability of this method by scaling a set of velocity slices at $Re_\theta=2240$ and $4430$ to $Re_\theta=8000$, and using them as inflow conditions for direct numerical simulations (DNS) of spatially developing TBLs growing from $Re_\theta=8000-9000$. The skin friction coefficient and shape factor predicted by the new method, regardless of the $\textit{base}$ $Re$ tested, is within $\pm3.5\%$ and $\pm0.5\%$, respectively, of that of a precursor simulation right from the inlet. Reynolds stresses match very well after approximately $8~\delta_{99_0}$. This gives an order of magnitude reduction in development length compared to other methods proposed in the literature. - oai:arXiv.org:2512.10623v1 - physics.flu-dyn - Fri, 12 Dec 2025 00:00:00 -0500 + SCOPE: Simple Coil Optimization for Plasma and Engineering + https://arxiv.org/abs/2512.16546 + arXiv:2512.16546v1 Announce Type: new +Abstract: Designing superconducting coils for a tokamak fusion device is a highly coupled, non-linear design problem. The coils have many disparate engineering requirements from structural to power electronics, as well strict limits placed on the system by the high temperature superconducting (HTS) cables. Simultaneously, the coils must be able to contain multiple plasma scenarios from inception, through ramp up, to flat top, and ramp down, all whilst applying a large, controlled, inductive voltage to drive current. In addition, we wish to optimize divertor separatrices to increase the likelihood of designing a suitable divertor strikepoint. Lastly, the physical limits of the entire tokamak must be taken into account and space reserved for support structures, access for maintenance schemes, and installation limits. The method outlined here uses a combined simulated annealing method to find optimal coil sizes and positions with a constrained quadratic or quartic optimization for the coil currents. The method is designed to optimize coils for multiple scenarios simultaneously, including ramp-ups, to avoid over optimization of a single design point. A key enabler is the efficient implementation that allows millions of evaluations to be performed in a few hours with modest computational power. This optimization method is part of a larger, iterative workflow which enables further, detailed design work to feedback on the optimization. + oai:arXiv.org:2512.16546v1 + physics.plasm-ph + Fri, 19 Dec 2025 00:00:00 -0500 new - http://creativecommons.org/licenses/by/4.0/ - Ronith Stanly, Timofey Mukha, Martin Karp, Stefano Markidis, Philipp Schlatter + http://arxiv.org/licenses/nonexclusive-distrib/1.0/ + Nathan Welch, Chris Marsden - Deep Photonic Reservoir Computing with On-chip Nonlinearity - https://arxiv.org/abs/2512.10626 - arXiv:2512.10626v1 Announce Type: new -Abstract: Reservoir computing, renowned for its low training cost, has emerged as a promising lightweight paradigm for efficient spatiotemporal processing,it remains challenging to realize deep photonic reservoir computing (DPRC) systems, due to the lack of scalable on-chip nonlinearity. Here, we introduce a versatile time delayed DPRC framework that natively supports deep and concurrent spatiotemporal processing entirely in the optical domain. At its core, the system leverages free carrier dynamics in silicon microring resonators to provide the fundamental nonlinearity and short term memory, and these nonlinear nodes are interconnected through true time delay lines that establish shared long-term memory. Benefiting from intrinsic physical nonlinearity and multi-timescale fading memory, this simple yet effective architecture demonstrates remarkable high dimensional representation capabilities. On the NTU RGB D benchmark, the parameter efficient DPRC system achieves superior action recognition accuracies compared to mainstream deep learning models, while requiring only a single shot regression training procedure. We further verify a prototype DPRC chip that excels across diverse dataset classification and time series prediction tasks. It enables a streamlined all optical pipeline between hierarchical layers, delivering a consistent computational density of 334.25 TOPs/mm2, independent of the reservoir depth and three orders of magnitude higher than conventional approaches. Moreover, its performance scales with near-zero hardware overhead by utilizing additional wavelength channels. This DPRC network is highly scalable on a silicon photonic platform, with flexible extension to hundreds of deep reservoir layers and parallel channels, paving the way toward intelligent optoelectronic systems for advanced real time processing and parallel decision making. - oai:arXiv.org:2512.10626v1 - physics.optics - Fri, 12 Dec 2025 00:00:00 -0500 + Decoding Molecular Geometries in Coulomb Explosion Imaging via Physics-Informed Deep Neural Network + https://arxiv.org/abs/2512.16559 + arXiv:2512.16559v1 Announce Type: new +Abstract: Determining the absolute configuration of gas-phase molecules in position-space has long been a fundamental challenge in molecular physics. While strong-field-induced Coulomb explosion imaging (CEI) has emerged as a powerful tool for probing molecular stereochemistry in momentum-space, reconstructing the original three-dimensional structure of polyatomic molecules remains a long-standing challenge due to the inherent complexity of multidimensional inversion. Here, we introduce a deep learning framework that bridges this gap by directly recovering position-space molecular structures from Coulomb explosion momentum patterns. Our approach combines CEI simulations with a neural network trained to establish the mapping between momentum-space Newton plots and real-space geometries. The trained model demonstrates high fidelity in reconstructing the structure of CHF$_3$ from experimental CEI data. This generalizable framework can not only be extended to other molecular systems but also opens avenues for time-resolved structural analysis of molecular dynamics. + oai:arXiv.org:2512.16559v1 + physics.atm-clus + Fri, 19 Dec 2025 00:00:00 -0500 new http://creativecommons.org/licenses/by/4.0/ - Jinlong Xiang, Youlve Chen, Yuchen Yin, Zhenyu Zhao, Chaojun Xu, An He, Xintong Lv, Yikai Su, Xuhan Guo + Xingyu Guo, Enliang Wang, Wenguang Wu, Zhaopeng Xing, Tuo Liu, Chunkai Xu, Xu Shan, Artem Rudenko, Daniel Rolles, Jing Chen, Xiangjun Chen - Field Reconstruction for High-Frequency Electromagnetic Exposure Assessment Based on Deep Learning - https://arxiv.org/abs/2512.10634 - arXiv:2512.10634v1 Announce Type: new -Abstract: Fifth-generation (5G) communication systems, operating in higher frequency bands from 3 to 300 GHz, provide unprecedented bandwidth to enable ultra-high data rates and low-latency services. However, the use of millimeter-wave frequencies raises public health concerns regarding prolonged electromagnetic radiation (EMR) exposure. Above 6 GHz, the incident power density (IPD) is used instead of the specific absorption rate (SAR) for exposure assessment, owing to the shallow penetration depth of millimeter waves. This paper proposes a hybrid field reconstruction framework that integrates classical electromagnetic algorithms with deep learning to evaluate the IPD of wireless communication devices operating at 30 GHz, thereby determining compliance with established RF exposure limits. An initial estimate of the electric field on the evaluation plane is obtained using a classical reconstruction algorithm, followed by refinement through a neural network model that learns the mapping between the initial and accurate values. A multi-antenna dataset, generated via full-wave simulation, is used for training and testing. The impacts of training strategy, initial-value algorithm, reconstruction distance, and measurement sampling density on model performance are analyzed. Results show that the proposed method significantly improves reconstruction accuracy, achieving an average relative error of 4.57% for electric field reconstruction and 2.97% for IPD estimation on the test dataset. Additionally, the effects of practical uncertainty factors, including probe misalignment, inter-probe coupling, and measurement noise, are quantitatively assessed. - oai:arXiv.org:2512.10634v1 - physics.app-ph - Fri, 12 Dec 2025 00:00:00 -0500 + Octave-spanning, deterministic single soliton generation in 4H-silicon carbide-on-insulator microring resonators + https://arxiv.org/abs/2512.16588 + arXiv:2512.16588v1 Announce Type: new +Abstract: The miniaturization of self-referencing frequency comb systems enables emerging applications in metrology and spectroscopy. One major challenge in realizing the chip-scale self-referencing function is to generate octave-spanning soliton microcombs with low operation power. Accessing soliton states is also not trivial due to the thermal effect. Though an auxiliary laser was utilized to compensate for the thermal effect, deterministic single soliton generation is still elusive, especially for broadband operation. In this work, dispersion management is performed for a 4H-silicon carbide-on-insulator (SiCOI) multi-mode microring resonator, benefiting from the submicron-confinement waveguide layout. The fundamental transverse electric (TE) mode is engineered to anomalous dispersion for two dispersive waves generation over an octave span. While a higher order TE mode is engineered to normal dispersion to accommodate the auxiliary light for thermal compensation. The normal dispersion prevents modulation-instability Kerr comb generation, allowing for a large soliton existence range. We achieve microring resonators with Q up to 5.8 million and sub-milli-watt-threshold Kerr comb generation. Combining the dispersion-managed design and high Q device, we demonstrate the deterministic generation of a single soliton comb spanning beyond an octave with a low on-chip power of 60 mW. Our demonstration paves the way to realize chip-scale, turn-key, self-referenced frequency combs. + oai:arXiv.org:2512.16588v1 + physics.optics + Fri, 19 Dec 2025 00:00:00 -0500 new http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Miao Cao, Zicheng Liu, Bazargul Matkerim, Tongning Wu, Changyou Li, Yali Zong, Bo Qi + Yi Zheng, Liping Zhou, Chengli Wang, Yanjing Zhao, Ailun Yi, Kresten Yvind, Xin Ou, Minhao Pu - Bound-free electron-positron pair production in combined Coulomb and constant crossed electromagnetic fields: a Schwinger-like process with intrinsic assistance - https://arxiv.org/abs/2512.10662 - arXiv:2512.10662v1 Announce Type: new -Abstract: The bound-free channel of electron-positron pair production by a highly charged bare ion in the presence of a strong constant crossed electromagnetic field is studied. To calculate the pair production rate, two different methods are applied and compared with each other: (i) a quasiclassical tunneling theory and (ii) a strong-field approximation, both equipped with appropriate Coulomb correction factors. The resulting rate, which depends nonperturbatively on both the Coulomb field of the ion and the constant crossed field, is calculated in a broad range of applied field strengths and nuclear charge numbers. Its functional form resembles the rate for a dynamically assisted Schwinger-like process, with the assistance being provided by the atomic binding energy of the created electron. - oai:arXiv.org:2512.10662v1 + Self-consistent bounds on Beyond the Standard Model bosons from spectroscopy of muonic atoms with magic nuclei + https://arxiv.org/abs/2512.16593 + arXiv:2512.16593v1 Announce Type: new +Abstract: Spectroscopy of muonic atoms is, to date, the most accurate technique to extract parameters of the nuclear charge density. The same reasons for their heightened sensitivity to nuclear parameters, a large overlap of the muonic wavefunction with the nucleus, makes them attractive systems to test Beyond the Standard Model (BSM) Physics. This raises concerns of self-consistency as the same data are used to, first, extract nuclear parameters, and second, check the consistency with BSM models. We combine the two steps and self-consistently extract the nuclear and BSM parameters. We show that the data are consistent with vanishing BSM coupling and extract robust exclusion bounds. We further note that the nuclear parameters change under the influence of those BSM couplings on the parameter fits and compare with the fit solely based on quantum electrodynamics (QED). + oai:arXiv.org:2512.16593v1 physics.atom-ph - hep-ph - Fri, 12 Dec 2025 00:00:00 -0500 + physics.optics + Fri, 19 Dec 2025 00:00:00 -0500 new http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - S. Remme, A. Eckey, S. Villalba-Ch\'avez, A. B. Voitkiv, C. M\"uller + K. A. Beyer, N. S. Oreshkina - Spatial-spectral mapping for long-duration broadband terahertz pulse generation in on-chip waveguide arrays - https://arxiv.org/abs/2512.10677 - arXiv:2512.10677v1 Announce Type: new -Abstract: Conventional approaches to terahertz (THz) pulse generation are restricted by the Fourier-transform limit, which hinders the creation of sources that combine long duration with broad bandwidth--a capability crucial for many spectroscopic and sensing applications. In this work, we overcome this challenge in the terahertz domain using an on-chip gradient waveguide array. The key is to spectrally disperse the pulse into spatially separated channels within a lithium niobate chip, effectively decoupling the design of temporal and spectral properties. We validate the source by distinguishing amino acid mixtures, demonstrating its tailored biosensing potential. This work establishes a novel mechanism for integrated THz generation, offering considerable promise for broadband spectroscopy and on-chip photonics. - oai:arXiv.org:2512.10677v1 - physics.optics - Fri, 12 Dec 2025 00:00:00 -0500 + Disruption Modelling for Engineering and Physics Design of Tokamak Energy ST-E1 Fusion Power Plant + https://arxiv.org/abs/2512.16604 + arXiv:2512.16604v1 Announce Type: new +Abstract: Plasma disruptions represent a critical challenge for high-performance tokamak operations, as they can compromise machine integrity and reduce operational availability. Although future fusion devices essentially need to incorporate strategies to minimise disruption occurrence, complete avoidance remains unattainable. Consequently, assessing and characterising unmitigated disruption consequences is fundamental for the design and qualification of next-generation fusion power plants. This work supports the pre-conceptual design of ST-E1, a low aspect-ratio Tokamak Fusion Power Plant developed by Tokamak Energy Ltd., by presenting a comprehensive disruption modelling approach applied across different design stages. The methodology integrates both physics and engineering considerations to evaluate the impact of disruptions on machine performance and structural integrity. From an engineering perspective, several ST-E1 layout options were analysed to investigate the electromagnetic response of key components under disruption-induced loads, enabling comparison between alternative design solutions. On the physics side, a broad set of disruption scenarios was explored, scanning operational space parameters, plasma-material interactions, and associated thermal loads. Furthermore, the study examined variations in disruption behaviour arising from different reference equilibria, focusing on a range starting from Double Null to Single Null configurations, reflecting the increasing up-down asymmetry consequences. The results reveal significant contrasts in plasma dynamics and structures electromagnetic behaviour between configurations, highlighting the importance of disruption modelling in guiding design choices. These analyses have proven instrumental in shaping ST-E1 development, offering critical insights for mitigating risks and optimising future fusion reactor designs. + oai:arXiv.org:2512.16604v1 + physics.plasm-ph + physics.comp-ph + Fri, 19 Dec 2025 00:00:00 -0500 new - http://creativecommons.org/licenses/by-nc-nd/4.0/ - Yibo Huang, Yao Lu, Haoyu Duan, Chao Wang, Xitan Xu, Jiwei Qi, Qiang Wu, Jingjun Xu + http://arxiv.org/licenses/nonexclusive-distrib/1.0/ + M. Scarpari, X. Zhang, K. Borowiec, P. F. Buxton, G. Calabro, S. Carusotti, A. Ciula, V. Godhani, J. D. Lore, E. N. J. Maartensson, S. A. M. McNamara, J. H. Nichols, M. Notazio, M. Robinson, M. Romanelli, J. Willis, ST-E1 Team - The Physics of Sustainability: Material and Power Constraints for the Long Term - https://arxiv.org/abs/2512.10680 - arXiv:2512.10680v1 Announce Type: new -Abstract: Much of today's sustainability discourse emphasizes efficiency, clean technologies, and smart systems, but largely underestimates fundamental physical constraints relating to energy-matter interactions. These constraints stem from the fact that Earth is a materially closed yet energetically open system, driven by the sustained but low power-density flux of solar radiation. This Perspective reframes sustainability within these axiomatic limits, integrating relevant timescales and orders of magnitude. We argue that fossil-fueled industrial metabolism is inherently incompatible with long-term viability, while post-fossil systems are surface-, materials-, and power-intensive. Long-term sustainability must therefore be defined not only by how much energy or material is used, but also by how it is used: favoring organic, carbon-based chemistry with limited reliance on purified metals, operating at low power density, and maintaining low throughput rates. Achieving this requires radical technological shifts toward life-compatible systems and biogeochemical circular processes, and, likely as a consequence, a paradigm change toward degrowth to a steady-state. These two shifts are mutually reinforcing and together provide the necessary foundation for any viable future. - oai:arXiv.org:2512.10680v1 + Resilience of coupled systems under deep uncertainty and dynamic complexity: An integrative literature review + https://arxiv.org/abs/2512.16608 + arXiv:2512.16608v1 Announce Type: new +Abstract: Resilience in coupled systems is increasingly critical in addressing global challenges such as climate change and pandemics. These systems show unpredictable behaviour due to dynamic complexity and deep uncertainty across spatiotemporal scales. Despite growing interest, few studies systematically integrate both concepts when assessing resilience. This paper conducts an integrative review of 102 English-language publications to identify gaps in current approaches. Findings reveal that most papers address lower levels of uncertainty and rarely consider dynamic complexity and deep uncertainty simultaneously, which limits the effectiveness of resilience strategies. To advance systems research, we propose a conceptual framework and practical tools to support researchers and decision-makers in evaluating and improving resilience. The paper also outlines future research directions for more robust, adaptive, and integrative resilience assessments. + oai:arXiv.org:2512.16608v1 physics.soc-ph - cond-mat.mtrl-sci - Fri, 12 Dec 2025 00:00:00 -0500 + cs.SY + eess.SY + Fri, 19 Dec 2025 00:00:00 -0500 new - http://creativecommons.org/licenses/by-sa/4.0/ - Jos\'e Halloy, Petros Chatzimpiros, Fran\c{c}ois Graner, Thomas Gregor + http://creativecommons.org/licenses/by-nc-nd/4.0/ + Jannie Coenen, V\'itor Vasconcelos, Heiman Wertheim, Marcel Olde Rikkert, Sophie Hadjisotiriou, Vittorio Nespeca, Tom Oreel, Rick Quax, Eti\"enne Rouwette, Vincent Marchau, Hubert Korzilius - MULE - A Co-Generation Fission Power Plant Concept to Support Lunar In-Situ Resource Utilisation - https://arxiv.org/abs/2512.10705 - arXiv:2512.10705v1 Announce Type: new -Abstract: For a sustained human presence on the Moon, robust in-situ resource utilisation supply chains to provide consumables and propellant are necessary. A promising process is molten salt electrolysis, which typically requires temperatures in excess of 900{\deg}C. Fission reactors do not depend on solar irradiance and are thus well suited for power generation on the Moon, especially during the 14-day lunar night. As of now, fission reactors have only been considered for electric power generation, but the reactor coolant could also be used directly to heat those processes to their required temperatures. In this work, a concept for a co-generation fission power plant on the Moon that can directly heat a MSE plant to the required temperatures and provide a surplus of electrical energy for the lunar base is presented. The neutron transport code Serpent 2 is used to model a ceramic core, gas-cooled very-high-temperature microreactor design and estimate its lifetime with a burnup simulation in hot conditions with an integrated step-wise criticality search. Calculations show a neutronically feasible operation time of at least 10 years at 100kW thermal power. The obtained power distributions lay a basis for further thermal-hydraulic studies on the technical feasibility of the reactor design and the power plant. - oai:arXiv.org:2512.10705v1 - physics.comp-ph - cs.CE - Fri, 12 Dec 2025 00:00:00 -0500 + Angular dependence of third-order law in anisotropic MHD turbulence + https://arxiv.org/abs/2512.16610 + arXiv:2512.16610v1 Announce Type: new +Abstract: In solar wind turbulence, the energy transfer/dissipation rate is typically estimated using MHD third-order structure functions calculated using spacecraft observations. However, the inherent anisotropy of solar wind turbulence leads to significant variations in structure functions along different observational directions, thereby affecting the accuracy of energy-dissipation rate estimation. An unresolved issue is how to optimise the selection of observation angles under limited directional sampling to improve estimation precision. We conduct a series of MHD turbulence simulations with different mean magnetic field strengths, $ B_0 $. Our analysis of the third-order structure functions reveals that the global energy dissipation rate estimated around a polar angle of $ \theta = 60^\circ$ agrees reasonably with the exact one for $ 0 \le B_0/b_{rms} \le 5 $, where $b_{rms}$ denotes the root-mean-square magnetic field fluctuation. The speciality of $60^\circ$ polar angle can be understood by the Mean Value Theorem of Integrals, since the spherical integral of the polar-angle component ($\widetilde{T_\theta}$) of the divergence of Yaglom flux is zero, and $\widetilde{T_\theta}$ changes sign around 60$^\circ$. Existing theory on the energy flux vector as a function of the polar angle is assessed, and supports the speciality of $60^\circ$ polar angle. The angular dependence of the third-order structure functions is further assessed with virtual spacecraft data analysis. The present results can be applied to measure the turbulent dissipation rates of energy in the solar wind, which are of potential importance to other areas in which turbulence takes place, such as laboratory plasmas and astrophysics. + oai:arXiv.org:2512.16610v1 + physics.space-ph + physics.flu-dyn + Fri, 19 Dec 2025 00:00:00 -0500 new http://creativecommons.org/licenses/by-nc-nd/4.0/ - Julius Mercz, Philipp Reiss, Christian Reiter + Bin Jiang, Zhuoran Gao, Yan Yang, Francesco Pecora, Kai Gao, Cheng Li, Sean Oughton, William Matthaeus, Minping Wan - Influence of the basins of attractions in the register jumps of the clarinet - https://arxiv.org/abs/2512.10721 - arXiv:2512.10721v1 Announce Type: new -Abstract: When playing the clarinet, opening the register hole allows for a transition from the first to the second register, producing a twelfth interval. On an artificial mouth, the blowing pressure range where the second register remains stable can be determined by gradually varying the blowing pressure while keeping the register hole open. However, when the register hole is opened while the instrument is already producing the first register, the range of blowing pressures that lead to a stable second register is narrower than the full stability zone of the second register. This phenomenon is investigated numerically by performing multiple hole openings at different times for each blowing pressure value. The evolution of the probability of reaching the second register is computed, and its relationship with the structure of the basin of attraction of the second register is analyzed. - oai:arXiv.org:2512.10721v1 - physics.class-ph - Fri, 12 Dec 2025 00:00:00 -0500 + Hypervelocity Impact Debris Cloud Trajectory-Planning based on Additive Manufactured Lattice Structures + https://arxiv.org/abs/2512.16611 + arXiv:2512.16611v1 Announce Type: new +Abstract: Space debris and micrometeoroid (MMOD) impacts pose a serious threat to the safe operation of spacecraft. However, traditional protective structures typically suffer from limitations such as excessive thickness and inadequate load-bearing capacity. Guided by the design concepts of debris-cloud deflection and hierarchical energy dissipation, this study proposes a trajectory-planning lattice protective structure. First, the lattice parameters and geometry were designed according to the functional relationship between the incident angle and the transmitted/ricochet trajectory angles. Subsequently, multi-angle hypervelocity impact experiments were carried out to evaluate the proposed lattice protection structure. In combination with post-impact CT three-dimensional reconstruction and smoothed particle hydrodynamics (SPH) numerical simulations, the protective mechanisms of the lattice structure were systematically characterized and clarified. The results demonstrate that, for three oblique incidence conditions, the lattice structure remained intact and significantly deflected the debris-cloud momentum direction while effectively dissipating its kinetic energy. The angled plates with gradient designs enabled continuous changes in the momentum direction and stepwise kinetic energy dissipation through multiple cycles of debrisation, dispersion, and trajectory deflection. This research presents a novel, engineering-ready approach for spacecraft MMOD protection and validates the potential of trajectory-planning lattice structures for hypervelocity impact defense. + oai:arXiv.org:2512.16611v1 + physics.app-ph + physics.space-ph + Fri, 19 Dec 2025 00:00:00 -0500 new http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Forum Acusticum 2025, European Acoustics Association, Jun 2025, Malaga, France - Nathan Szwarcberg (LMA), Tom Colinot (LMA), Christophe Vergez (LMA), Micha\"el Jousserand - - - Evaluation of preCICE (version 3.3.0) in an Earth System Model Regridding Benchmark - https://arxiv.org/abs/2512.10724 - arXiv:2512.10724v1 Announce Type: new -Abstract: In Earth System Modeling (ESM), meshes of different models usually do not match, requiring data mapping algorithms implemented in coupling software. Valcke et al. recently introduced a benchmark to evaluate such algorithms and compared implementations in four specialized ESM couplers. In this paper, we assess preCICE, a general-purpose coupling library not limited to ESM, using this benchmark and compare our results to the original study. The generality of preCICE with its larger community offers potential benefits to ESM applications, but the software naturally lacks ESM-specific solutions. We describe necessary pre- and postprocessing steps to make the benchmark tangible for preCICE. Overall, preCICE achieves comparable results; using its radial basis function mapping yields significantly lower errors. - oai:arXiv.org:2512.10724v1 - physics.ao-ph - Fri, 12 Dec 2025 00:00:00 -0500 - new - http://creativecommons.org/licenses/by-sa/4.0/ - Alex Hocks, Benjamin Uekermann + Bilin Zheng, Xiao Kang, Xiaoyu Zhang, Hao Zhou, Mengchuan Xu, Chang Liu - Motor shot noise explains active fluctuations in a single cilium - https://arxiv.org/abs/2512.10727 - arXiv:2512.10727v1 Announce Type: new -Abstract: Mesoscopic fluctuations reveal stochastic dynamics of molecules in both inanimate and living matter. We investigate how small-number fluctuations shape the collective dynamics of molecular motors using motile cilia as model system. We theoretically show that fluctuations in the number of bound motors are sufficient to explain experimentally observed fluctuations, including correlation length and ``phase slips'' of intra-cilium synchronization. Our findings constrain theories of motor control and establish a link between microscopic motor noise and mesoscopic non-equilibrium dynamics. - oai:arXiv.org:2512.10727v1 - physics.bio-ph - Fri, 12 Dec 2025 00:00:00 -0500 + Photon Accelerator in Magnetized Plasma + https://arxiv.org/abs/2512.16630 + arXiv:2512.16630v1 Announce Type: new +Abstract: Strong magnetic fields and plasmas are intrinsically linked in both terrestrial laboratory experiments and in space phenomena. One of the most profound consequences of that is the change in relationship between the frequency and the wave number of electromagnetic waves propagating in plasma in the presence of such magnetic fields when compared to the case without these fields. Furthermore, magnetic fields alter electromagnetic wave interaction with relativistic plasma waves, resulting in different outcomes for particle and radiation generation. For a relativistic plasma wave-based photon acceleration this leads to an increased frequency gain, and, thus, potentially to higher efficiency. The influence of a magnetic field leads to quantitative and qualitative change in the properties of photon acceleration, amplifying the increase in the electromagnetic wave frequency. + oai:arXiv.org:2512.16630v1 + physics.plasm-ph + astro-ph.HE + Fri, 19 Dec 2025 00:00:00 -0500 new http://creativecommons.org/licenses/by/4.0/ - Maximilian Kotz, Veikko F. Geyer, Benjamin M. Friedrich + Sergei Bulanov, Stepan Bulanov, Timur Esirkepov, Gianluca Gregori, Gabriele Grittani, Brandon Russell, Alec Thomas, Petr Valenta - Optimized matching conditions for self-guided laser wakefield accelerators - https://arxiv.org/abs/2512.10728 - arXiv:2512.10728v1 Announce Type: new -Abstract: We revisit the matching conditions for self-guided laser pulse propagation in plasma and refine their formulation to maximize the energy of electrons produced via laser wakefield acceleration. Bayesian optimization, combined with particle-in-cell simulations carried out in a quasi-three-dimensional geometry and a Lorentz-boosted frame, is employed. The optimization identifies the maximum electron energy that a self-guided laser wakefield accelerator, driven by a laser of a given energy, can produce, together with the corresponding acceleration distance. Our results further demonstrate that electrons with energies close to the maximum value can be obtained across a relatively wide range of input parameters and without the need for their precise tuning. This provides substantial flexibility for experimental implementation and significantly relaxes the operational constraints associated with self-guided laser wakefield accelerators. - oai:arXiv.org:2512.10728v1 - physics.plasm-ph - physics.acc-ph - physics.comp-ph - Fri, 12 Dec 2025 00:00:00 -0500 + Direct inversion of data-space Hessian for efficient time-domain extended-source waveform inversion using the multiplier method + https://arxiv.org/abs/2512.16642 + arXiv:2512.16642v1 Announce Type: new +Abstract: The augmented Lagrangian (AL) method has been successfully applied for solving the full waveform inversion (FWI) problem. In AL-based FWI, the Lagrange multipliers serve as source extensions, offering several advantages to the inversion, such as improved robustness to cycle skipping, faster convergence, and simplified penalty parameter tuning. Time-domain applications of this method have been enabled by reformulating the optimization problem in the data space, significantly reducing memory requirements by projecting source-side multipliers into the data space. These data-side multipliers act as data extensions, effectively expanding the data space. A key challenge in these methods lies in computing the data-side multipliers, which involves solving a linear system to deblur the data residuals using the data-space Hessian matrix before it serves as the adjoint source. This Hessian matrix is prohibitively large to construct and invert explicitly. Iterative Krylov methods can be applied to solve this system as inner iterations, but they require two PDE solves per inner iteration per source, leading to significant computational costs. In this work, we present a key improvement to extended waveform inversion based on multiplier methods. We propose a novel approach that significantly reduces the computational cost of Hessian inversion. The method computes receiver-side Green functions in the time domain and directly constructs frequency-domain Hessian matrices for all required frequencies. These Hessian matrices, with dimensions equal to the number of receivers, can be computed, inverted, and stored in memory. Once constructed, they can be used simultaneously for all sources, further enhancing efficiency. Numerical experiments demonstrate the substantial computational gains achieved by the proposed method, highlighting its effectiveness for extended-source FWI in the time domain. + oai:arXiv.org:2512.16642v1 + physics.geo-ph + Fri, 19 Dec 2025 00:00:00 -0500 new - http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - P. Valenta, K. G. Miller, B. K. Russell, M. Lama\v{c}, M. Jech, G. M. Grittani, S. V. Bulanov + http://creativecommons.org/licenses/by/4.0/ + Mahdi Sonbolestan, Ali Gholami - PMB-NN: Physiology-Centred Hybrid AI for Personalized Hemodynamic Monitoring from Photoplethysmography - https://arxiv.org/abs/2512.10745 - arXiv:2512.10745v1 Announce Type: new -Abstract: Continuous monitoring of blood pressure (BP) and hemodynamic parameters such as peripheral resistance (R) and arterial compliance (C) are critical for early vascular dysfunction detection. While photoplethysmography (PPG) wearables has gained popularity, existing data-driven methods for BP estimation lack interpretability. We advanced our previously proposed physiology-centered hybrid AI method-Physiological Model-Based Neural Network (PMB-NN)-in blood pressure estimation, that unifies deep learning with a 2-element Windkessel based model parameterized by R and C acting as physics constraints. The PMB-NN model was trained in a subject-specific manner using PPG-derived timing features, while demographic information was used to infer an intermediate variable: cardiac output. We validated the model on 10 healthy adults performing static and cycling activities across two days for model's day-to-day robustness, benchmarked against deep learning (DL) models (FCNN, CNN-LSTM, Transformer) and standalone Windkessel based physiological model (PM). Validation was conducted on three perspectives: accuracy, interpretability and plausibility. PMB-NN achieved systolic BP accuracy (MAE: 7.2 mmHg) comparable to DL benchmarks, diastolic performance (MAE: 3.9 mmHg) lower than DL models. However, PMB-NN exhibited higher physiological plausibility than both DL baselines and PM, suggesting that the hybrid architecture unifies and enhances the respective merits of physiological principles and data-driven techniques. Beyond BP, PMB-NN identified R (ME: 0.15 mmHg$\cdot$s/ml) and C (ME: -0.35 ml/mmHg) during training with accuracy similar to PM, demonstrating that the embedded physiological constraints confer interpretability to the hybrid AI framework. These results position PMB-NN as a balanced, physiologically grounded alternative to purely data-driven approaches for daily hemodynamic monitoring. - oai:arXiv.org:2512.10745v1 - physics.med-ph - cs.LG - Fri, 12 Dec 2025 00:00:00 -0500 + Temperature dependence of the long-term annealing behavior of neutron irradiated diodes from 8-inch p-type silicon wafers + https://arxiv.org/abs/2512.16643 + arXiv:2512.16643v1 Announce Type: new +Abstract: To face the higher levels of radiation due to the 10-fold increase in integrated luminosity during the High-Luminosity LHC, the CMS detector will replace the current Calorimeter Endcap (CE) using the High-Granularity Calorimeter (HGCAL) concept. The high-radiation regions of the the CE, where fluences between $1\cdot10^{14}~n_{eq}/cm^{2}$ and $1\cdot10^{16}~n_{eq}/cm^{2}$ and doses of up to 2\,MGy are expected considering an integrated luminosity of $3\,ab^{-1}$, will be equipped with silicon pad sensors. This includes the entire electromagnetic as well as parts of the hadronic section of the CE. The silicon sensors are processed on 8-inch p-type wafers with an active thickness of 300\,\textmu m, 200\,\textmu m and 120\,\textmu m and cut into hexagonal shapes for optimal use of the full wafer area and tiling. With each main sensor, several small test structures (e.g. pad diodes) are hosted on the wafers, used for quality assurance and radiation hardness tests. In order to investigate the radiation-induced bulk damage, these diodes have been irradiated with reactor neutrons at JSI (Jozef Stefan Institute, Ljubljana, Slovenia) to fluences between $5\cdot10^{14}~n_{eq}/cm^{2}$ and $1.5\cdot10^{16}~n_{eq}/cm^{2}$. This study focuses on the isothermal annealing behavior of the bulk material at different temperatures between 5.5{\deg}C and 60{\deg}C using electrical characterization and charge collection measurements. The results are used to extract the annealing time constants for this material and fluence range based on the Hamburg model approach to allow an estimation of the expected annealing effects in silicon sensors during the year-end technical stops and the long HL-LHC shutdowns. The annealing parameters found will make it possible to model the annealing behavior of p-type silicon detector projects at HL-LHC fluence ranges better than the existing Hamburg model. + oai:arXiv.org:2512.16643v1 + physics.ins-det + hep-ex + Fri, 19 Dec 2025 00:00:00 -0500 new - http://creativecommons.org/licenses/by-nc-nd/4.0/ - Yaowen Zhang, Libera Fresiello, Peter H. Veltink, Dirk W. Donker, Ying Wang + http://creativecommons.org/licenses/by/4.0/ + Leena Diehl, Oliwia Kaluzinska, Marie M\"uhlnikel, Max Andersson, Natalya Gerassyova, Jenan Amer, Eva Sicking, Dana Groner, Jan Kieseler, Matteo Defranchis - Mixing by offshore wind infrastructure: Resolving the density stratified wakes past vertical cylinders - https://arxiv.org/abs/2512.10751 - arXiv:2512.10751v1 Announce Type: new -Abstract: This work is focussed on understanding the fundamental fluid dynamics of tidal wakes generated by offshore wind infrastructure in stratified waters, using direct numerical simulations. The tidal flows past the structures are approximated by a uniform quiescent background flow with a two-layer density profile, interacting with a vertically oriented cylinder. Through these simulations we identify the processes through which turbulence generated in the wake of the structures leads to vertical mixing across the thermocline.We identify two fundamentally different flow regimes, dependent on both the stratification strength and the flow Reynolds number. The 'weakly stratified' wake is characterised by a highly energetic wake and a dominance of horizontal shear. As a result, vertical mixing occurs much further downstream than the region of maximum turbulent kinetic energy production. In contrast, the `strongly stratified' wake regime is characterised by a large-scale recirculation region that develops across the thermocline which generates significant vertical shearing. This subsequently leads to time-independent standing waves which account for up to 10% of the total energy budget, and have characteristics similar to 'mode 2' internal solitary waves. The vertical shear introduced near the edges of the thermocline is highly efficient at local mixing, but vertical fluctuations are quickly suppressed as the wake propagates further downstream. We speculate that the emergence of this flow regime may explain discrepancies in previous field observations, which have been unable to detect a coherent wake far downstream of offshore wind infrastructure. Future work should focus on bridging the scale gaps between idealised simulations and the field. - oai:arXiv.org:2512.10751v1 - physics.flu-dyn - Fri, 12 Dec 2025 00:00:00 -0500 + Subspace tracking: a novel measurement method to test the standard phase noise model of optical frequency combs + https://arxiv.org/abs/2512.16652 + arXiv:2512.16652v1 Announce Type: new +Abstract: The introduction of digital signal processing (DSP) assisted coherent detection has been a cornerstone of modern fiber-optic communication systems. The ability to digitally, i.e. after analogue-to-digital converter, compensate for chromatic dispersion, polarization mode dispersion, and phase noise has rendered traditional analog feedback loops largely obsolete. While analog techniques remain prevalent for phase noise characterization of single-frequency lasers, the phase noise characterization of optical frequency combs presents a greater challenge. This complexity arises from different number of phase noise sources affecting an optical frequency comb. Here, we show how a phase noise measurement techniques method based on multi-heterodyne coherent detection and DSP-based subspace tracking can be used to identify, measure and quantify various phase noise sources associated with an optical frequency comb. + oai:arXiv.org:2512.16652v1 + physics.optics + eess.SP + Fri, 19 Dec 2025 00:00:00 -0500 new http://creativecommons.org/licenses/by/4.0/ - Charlie J. Lloyd, Robert M. Dorrell + Darko Zibar, Holger Heeb{\o}ll, Jasper Riebesehl, Michael Galili, Francesco Da Ros, Aleksandr Razumov - Accurate laboratory testing of low-frequency triaxial vibration sensors under various environmental conditions - https://arxiv.org/abs/2512.10771 - arXiv:2512.10771v1 Announce Type: new -Abstract: Triaxial vibration sensor are widely used used in various application. Recently, low-cost sensors based on micro electro mechanical system (MEMS) technology are also becoming more widely adopted. However, their measurement accuracy can be affected by environmental factors such as temperature. In this study, we developed an environmental testing system integrated with a triaxial vibration exciter. The system can reproduce long-stroke, low-frequency triaxial vibrations -- such as those caused by huge earthquakes -- under temperatures ranging from $-30~^\circ\mathrm{C}$ to $+80~^\circ\mathrm{C}$. Using this system, the measurement accuracy of vibration sensors can be evaluated under different environmental conditions. The system provides highly accurate reference measurements using a laser interferometer and reference accelerometers that are primarily calibrated within the system. The overall accuracy of the reference vibration measurement is estimated to be approximately 0.23~\%. Based on these reference measurements, we investigated the accuracy of earthquake observations using a MEMS accelerometer as a demonstration. The system configuration and testing procedures are presented in this paper. - oai:arXiv.org:2512.10771v1 - physics.ins-det - Fri, 12 Dec 2025 00:00:00 -0500 + Self-Affine Scaling of Earth's Islands + https://arxiv.org/abs/2512.16659 + arXiv:2512.16659v1 Announce Type: new +Abstract: Earth's relief is approximately self-affine, meaning a zoom-in on a small region looks statistically similar to a large region upon a suitable rescaling. Fractional Brownian surfaces give an idealized self-affine model of Earth's relief with one parameter, the Hurst exponent $H$, characterizing the roughness of the surface. To quantitatively assess agreement with Earth elevation data, we compile a large dataset of topographic profiles of islands (N=131,063 with the range of areas covering 8+ orders of magnitude) and obtain four estimates for the Hurst exponent of Earth's surface by fitting four statistical laws from the theory of self-affine surfaces concerning islands: (i) distribution of areas, (ii) volume-area relationship, (iii) perimeter-area relationship, and (iv) maximum height-area relationship. The estimated Hurst exponents differ greatly, indicating different fractal scaling behavior for different geometric features, but are sorted in order of increasing expected influence of erosion at the shorelines. + oai:arXiv.org:2512.16659v1 + physics.geo-ph + cond-mat.stat-mech + nlin.AO + Fri, 19 Dec 2025 00:00:00 -0500 new http://creativecommons.org/licenses/by/4.0/ - Tomofumi Shimoda, Wataru Kokuyama, Hideaki Nozato + Matthew Oline, Jeremy Hoskins, David Seekell, Mary Silber, B. B. Cael - Theoretical and experimental development of a high-conversion-efficiency rectifier at X-band - https://arxiv.org/abs/2512.10774 - arXiv:2512.10774v1 Announce Type: new -Abstract: Voltage doubler rectifiers are usually applied to systems with high voltage and low current requirement. An X band voltage doubler rectifier has been developed with 72% conversion efficiency. To the best of our knowledge, the obtained rectifying efficiency is the maximum reported to date at X band with Schottky diodes. The working characteristics of the diodes in the voltage doubler rectifier are analyzed in detail. Closed-form equations of diode input impedance and rectifying efficiency are presented and validated using Advanced Design System simulations. The matching network design of the proposed rectifier is based on the closed-form equations. The preliminary rectifying efficiency is predicted by the closed-form equations as well. Measured and simulated results are in good agreement. - oai:arXiv.org:2512.10774v1 + Acoustic scattering singularities via quasi-Bound states in the continuum + https://arxiv.org/abs/2512.16672 + arXiv:2512.16672v1 Announce Type: new +Abstract: Non-Hermitian systems enable advanced control of wave propagation by exploiting engineered losses. This introduces an additional degree of freedom that permits the emergence of exceptional points (EPs). In this letter, we theoretically and experimentally demonstrate the control of scattering singularities in a non-Hermitian acoustic system using quasibound states in the continuum (qBICs). Through Friedrich Wintgen interference, the losses of a two port cavity are tuned until achieving critical coupling, yielding narrowband coherent perfect absorption (CPA) with a quality factor of 140. Additionally, by coupling two distinct resonators, we observe the emergence of an EP, where both eigenvalues simultaneously coalesce and vanish, resulting in narrowband unidirectional absorption. Our results establish a connection between qBICs and scattering singularities, and offer a route toward acoustic devices featuring narrowband resonances and tunable radiative losses. + oai:arXiv.org:2512.16672v1 physics.app-ph - Fri, 12 Dec 2025 00:00:00 -0500 + Fri, 19 Dec 2025 00:00:00 -0500 new http://creativecommons.org/licenses/by/4.0/ - 10.1017/S1759078716001197 - International Journal of Microwave and Wireless Technologies 9.5 (2017): 985-994 - Feifei Tan, Changjun Liu + Anis Maddi, Mourad Oudich, Aurelien Merkel, Julio A. Iglesias Mart\'inez, Badreddine Assouar - Deflating the Spacetime-Matter Dichotomy - https://arxiv.org/abs/2512.10775 - arXiv:2512.10775v1 Announce Type: new -Abstract: In this paper we analyse scalar-tensor theories-specific instances of which include mainstream inflation and dark energy models-in light of the spacetime-matter dichotomy. We argue that it is difficult to categorise the scalar fields as either a pure aspect of the spacetime structure or a pure form of matter, by focusing on the Jordan vs Einstein frames of these theories. We present and evaluate various interpretational options available, concluding that the spacetime-matter dichotomy becomes untenable in this context. At the same time, the ontological and conceptual category of spacetime can be decoupled from that of gravity, with the latter remaining viable in the context of scalar-tensor theories. - oai:arXiv.org:2512.10775v1 - physics.hist-ph - gr-qc - Fri, 12 Dec 2025 00:00:00 -0500 + QMCkl: A Kernel Library for Quantum Monte Carlo Applications + https://arxiv.org/abs/2512.16677 + arXiv:2512.16677v1 Announce Type: new +Abstract: Quantum Monte Carlo (QMC) methods deliver highly accurate electronic structure calculations but are computationally intensive. The quantum Monte Carlo kernel library (QMCkl) provides a modular, portable collection of high-performance kernels implementing the core building blocks of QMC calculations. It offers a C-compatible API, supports the TREXIO standard for input, and covers essential QMC kernels including atomic and molecular orbitals, cusp corrections, Jastrow factor, and the necessary derivatives also to perform variational and structural optimization. QMCkl separates algorithmic development from hardware-specific tuning by combining human-readable reference implementations with performance-optimized kernels that produce identical numerical results. The library enables consistent, efficient, and reproducible simulations across different QMC codes and architectures, and achieves substantial speedups in the evaluation of the energy and its derivatives. Beyond QMC, QMCkl can accelerate deterministic quantum chemistry workflows and visualization tools, promoting cross-code interoperability and simplifying high-performance scientific software development. + oai:arXiv.org:2512.16677v1 + physics.chem-ph + physics.comp-ph + Fri, 19 Dec 2025 00:00:00 -0500 new - http://creativecommons.org/licenses/by/4.0/ - Antonio Ferreiro, Alex Fleuren, Niels C. M. Martens + http://arxiv.org/licenses/nonexclusive-distrib/1.0/ + Emiel Slootman, Vijay Gopal Chilkuri, Aurelien Delval, Max Hoffer, Tommaso Gorni, Fran\c{c}ois Coppens, Joris van de Nes, Ram\'on L. Panad\'es-Barrueta, Evgeny Posenitskiy, Abdallah Ammar, Edgar Josu\'e Landinez Borda, Kevin Camus, Oto Kohul\`ak, Emmanuel Giner, Pablo de Oliveira Castro, Cedric Valensi, William Jalby, Claudia Filippi, Anthony Scemama - Opportunities and Challenges in Harnessing Digital Technology for Effective Teaching and Learning - https://arxiv.org/abs/2512.10777 - arXiv:2512.10777v1 Announce Type: new -Abstract: Most of today's educators are in no shortage of digital and online learning technologies available at their fingertips, ranging from Learning Management Systems such as Canvas, Blackboard, or Moodle, online meeting tools, online homework, and tutoring systems, exam proctoring platforms, computer simulations, and even virtual reality/augmented reality technologies. Furthermore, with the rapid development and wide availability of generative artificial intelligence (GenAI) services such as ChatGPT, we are just at the beginning of harnessing their potential to transform higher education. Yet, facing the large number of available options provided by cutting-edge technology, an imminent question on the mind of most educators is the following: how should I choose the technologies and integrate them into my teaching process so that they would best support student learning? We contemplate over these types of important and timely questions and share our reflections on evidence-based approaches to harnessing digital learning tools using a Self-regulated Engaged Learning Framework we have employed in our research in physics education that can be valuable for educators in other disciplines. - oai:arXiv.org:2512.10777v1 - physics.ed-ph - cs.HC - Fri, 12 Dec 2025 00:00:00 -0500 + CARONTE: a Physics-Informed Extreme Learning Machine-Based Algorithm for Plasma Boundary Reconstruction in Magnetically Confined Fusion Devices + https://arxiv.org/abs/2512.16689 + arXiv:2512.16689v1 Announce Type: new +Abstract: In this work, we propose a novel physics informed neural network based algorithm for real time plasma boundary reconstruction in tokamak devices. The approach is based on a single Extreme Learning Machine network used to solve the homogeneous Grad Shafranov equation, which is required to identify the plasma boundary. This architecture enables the real time training of the network parameters using the available magnetic sensor data and, consequently, dynamically adapting the network output to the evolving plasma equilibrium. We demonstrate that, the network performs accurate plasma boundary reconstruction for complex configurations, outperforming well established methods, such as the algorithm used for decades at the Joint European Torus, the world's largest tokamak, until it ceased operation in 2023. Indeed, compared to the latter, the proposed solution better generalizes the poloidal flux function, without requiring algorithm retuning across different plasma equilibria. The proposed neural network reconstructor demonstrates also greater robustness with respect to noise on the magnetic measurements. Moreover, this method takes advantage of the generalization power of neural networks but without the need for extensive, time consuming training based on a huge amount of experimental data, making its implementation on existing devices straightforward. + oai:arXiv.org:2512.16689v1 + physics.plasm-ph + Fri, 19 Dec 2025 00:00:00 -0500 new - http://creativecommons.org/licenses/by-nc-sa/4.0/ - 10.3390/higheredu4010006 - Chen, Z.; Singh, C. Opportunities and Challenges in Harnessing Digital Technology for Effective Teaching and Learning. Trends High. Educ. 2025, 4, 6 - Zhongzhou Chen, Chandralekha Singh + http://creativecommons.org/licenses/by-nc-nd/4.0/ + Federico Fiorenza, Sara Dubbioso, Gianmaria De Tommasi, Alfredo Pironti - Developing and Evaluating a Large Language Model-Based Automated Feedback System Grounded in Evidence-Centered Design for Supporting Physics Problem Solving - https://arxiv.org/abs/2512.10785 - arXiv:2512.10785v1 Announce Type: new -Abstract: Generative AI offers new opportunities for individualized and adaptive learning, particularly through large language model (LLM)-based feedback systems. While LLMs can produce effective feedback for relatively straightforward conceptual tasks, delivering high-quality feedback for tasks that require advanced domain expertise, such as physics problem solving, remains a substantial challenge. This study presents the design of an LLM-based feedback system for physics problem solving grounded in evidence-centered design (ECD) and evaluates its performance within the German Physics Olympiad. Participants assessed the usefulness and accuracy of the generated feedback, which was generally perceived as useful and highly accurate. However, an in-depth analysis revealed that the feedback contained factual errors in 20% of cases; errors that often went unnoticed by the students. We discuss the risks associated with uncritical reliance on LLM-based feedback systems and outline potential directions for generating more adaptive and reliable LLM-based feedback in the future. - oai:arXiv.org:2512.10785v1 - physics.ed-ph - cs.AI - cs.HC - Fri, 12 Dec 2025 00:00:00 -0500 + Fabrication Optimization of Suspended Stencil Mask Lithography for Multi-Terminal Josephson Junctions + https://arxiv.org/abs/2512.16690 + arXiv:2512.16690v1 Announce Type: new +Abstract: Stencil mask lithography is an advanced technique for fully in-situ fabricating Josephson junctions, which is increasingly being used for multi-terminal Josephson junctions. This study provides information on the optimal mask design and mask reliability. For this, 270 mask designs were systematically fabricated and investigated under scanning electron microscope. Reliable statements are made about mask yield, minimal dimensions, and systematic dependencies on the number of superconducting terminals. We find that stencil mask lithography can be used reliably for fabricating multi-terminal Josephson junctions, enabling lateral mask dimensions down to 40$\,$nm on average. + oai:arXiv.org:2512.16690v1 + physics.app-ph + Fri, 19 Dec 2025 00:00:00 -0500 new - http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Holger Maus, Paul Tschisgale, Fabian Kieser, Stefan Petersen, Peter Wulff + http://creativecommons.org/licenses/by/4.0/ + Justus Teller, Abdur Rehman Jalil, Florian Lentz, Detlev Gr\"utzmacher, Thomas Sch\"apers - The dynamics of thermalisation in the Galerkin-truncated, three-dimensional Euler equation - https://arxiv.org/abs/2512.10788 - arXiv:2512.10788v1 Announce Type: new -Abstract: The inviscid, partial differential equations of hydrodynamics when projected via a Galerkin-truncation on a finite-dimensional subspace spanning wavenumbers $-{\bf K}_{\rm G} \le {\bf k} \le {\bf K}_{\rm G}$, and hence retaining a finite number of modes $N_{\rm G}$, lead to absolute equilibrium states. We review how the Galerkin-truncated, three-dimensional, incompressible Euler equation thermalises and its connection to questions in turbulence. We also discuss an emergent pseudo-dissipation range in the energy spectrum and the time-scales associated with thermalisation. - oai:arXiv.org:2512.10788v1 - physics.flu-dyn - cond-mat.stat-mech - nlin.CD - Fri, 12 Dec 2025 00:00:00 -0500 + Inequality traps detected in sustainable development goals data + https://arxiv.org/abs/2512.16703 + arXiv:2512.16703v1 Announce Type: new +Abstract: The relationship between inequality and the biosphere has been hypothesized to mutual dependecies and feedbacks. If that is true, such feedbacks may give rise to inequality regimes and potential tipping points between them. Here we explore synergies and trade-offs between inequality and biosphere-related sustainable development goals. We used the openly available SDG datasets by the World Bank (WB) and United Nations (UN) and applied ordination methods to distill interactions between economic inequality and the environmental impact across countries. Our results confirm the existence of inequality regimes, and we find preliminary evidence that corruption may be a candidate driver of tipping between regimes. + oai:arXiv.org:2512.16703v1 + physics.soc-ph + Fri, 19 Dec 2025 00:00:00 -0500 new - http://creativecommons.org/licenses/by-nc-sa/4.0/ - Rajarshi, Mohammad Saif Khan, Prateek Anand, Samriddhi Sankar Ray + http://creativecommons.org/licenses/by/4.0/ + Juan C. Rocha, Maike Hamann, Jiangxiao Qiu, Tong Wu, Tomas Chaigneau, Emilie Lindkvist, Caroline Schill, Alon Shepon, Andrew R. Tilman, Geraldine D. Verkleij, Anne-Sophie Cr\'epin, Carl Folke - Ultrahigh-Q chiral resonances empowered by multi-head attention deep learning - https://arxiv.org/abs/2512.10798 - arXiv:2512.10798v1 Announce Type: new -Abstract: High quality (Q) factor optical chiral resonators are indispensable for many chiral photonic devices. Designing ultrahigh Q-factors in chiral metasurfaces traditionally relies on extensive parameter scanning, which is time-consuming and inefficient. While deep learning now provides a rapid design alternative, conventional models still face challenges in accurately predicting ultrahigh Q-factor spectral characteristics. In this study, we introduce a multi-head attention network (MuHAN) to accelerate the design of ultrahigh Q-factor optical chiral resonators in bilayer metasurfaces. MuHAN achieves forward spectral predictions in approximately 10ms, thousands of times faster than finite-difference time-domain simulations, boasting 99.85% and 99.9% accuracy for forward and inverse predictions, respectively. By transferring the learned physical principles, we perform inverse design of nanoscale structures with ultrahigh Q-factors (up to 2.9910E5) based on chiral quasi-bound states in the continuum (quasi-BICs) at minimal computational cost. Our rapid design tool, based on MuHAN, enables high-performance encryption imaging, bridging deep learning with high-Q chiral metasurfaces for advanced sensing, laser, and detection applications. - oai:arXiv.org:2512.10798v1 + Intrinsic temporal and spectral mixing in time-resolved terahertz spectroscopy + https://arxiv.org/abs/2512.16713 + arXiv:2512.16713v1 Announce Type: new +Abstract: In an ultrafast optical-pump terahertz-probe measurement, the photoinduced material response can be modulated on a timescale shorter than the extent of the THz pulse. In this situation, the measured time-frequency response deviates from a simple time-dependent linear response. When full two-dimensional time-frequency maps are measured, this yields complex features that can be incorrectly assigned to a photoexcited coherent response. We investigate this experimentally via the measured response of photoexcited SnSe, whereby photoinduced phase change dynamics lead to ultrafast changes of the charge carrier and lattice optical conductivity response. Two-dimensional time-frequency THz transmission maps subsequently show unexpected time-frequency features at early pump-probe delay times. These features are reproduced in both finite-difference time-domain simulations of the THz experiment and in an extension of non-equilibrium response function theory, demonstrating their systematic origin. This work improves the understanding of systematic effects in high time resolution optical-pump THz-probe spectroscopy, and explores the conditions in which they are likely to appear. + oai:arXiv.org:2512.16713v1 physics.optics - Fri, 12 Dec 2025 00:00:00 -0500 + Fri, 19 Dec 2025 00:00:00 -0500 new - http://creativecommons.org/licenses/by/4.0/ - Cong Zhang, Jiaju Wu, Huazheng Wu, Yufei Liu, Xu Yang, Na Liu, Chaoyang Wang, Peipei Chen, Chenggang Yan, Seng Yang, Xingguang Liu, Shaowei Jiang + http://arxiv.org/licenses/nonexclusive-distrib/1.0/ + Benjamin J. Dringoli, David G. Cooke - Data-driven Pressure Recovery in Diffusers - https://arxiv.org/abs/2512.10801 - arXiv:2512.10801v1 Announce Type: new -Abstract: This paper investigates the application of a data-driven technique based on retrospective cost optimization to optimize the frequency of mass injection into an S-shaped diffuser, with the objective of maximizing the pressure recovery. Experimental data indicated that there is an optimal injection frequency between 100 Hz and 300 Hz with a mass flow rate of 1 percent of the free stream. High-fidelity numerical simulations using compressible unsteady Reynolds-Averaged Navier-Stokes (URANS) are conducted to investigate the mean and temporal features resulting from mass injection into an S-shaped diffuser with differing injection speeds and pulse frequencies. The results are compared with experiments to confirm the accuracy of the numerical solution. Overall, 2-D simulations are relatively in good agreement with the experiment, with 3-D simulations currently under investigation to benchmark the effect of spanwise instabilities. Simulation results with the proposed data-driven technique show improvements upon a baseline case by increasing pressure recovery and reducing the region of flow recirculation within the diffuser. - oai:arXiv.org:2512.10801v1 - physics.flu-dyn - cs.SY - eess.SY - Fri, 12 Dec 2025 00:00:00 -0500 + Polymer-inspired mechanical metamaterials + https://arxiv.org/abs/2512.16732 + arXiv:2512.16732v1 Announce Type: new +Abstract: Metamaterials benefit from unique architected patterns to achieve lightweight with exceptional mechanical properties inaccessible to conventional materials. Typical mechanical metamaterials mimic crystal structures with close-packed lattices, exhibit high structural stiffness but suffer from reduced flexibility and abrupt fracture similar to atomic debonding. Here, we demonstrate a new class of polymer-inspired metamaterials by translating, understanding, and programming the deformation and strengthening mechanics of polymers. By combining the metamaterial programmability with polymer-like mechanics, we also program crosslinking, proto-crystalline order, and entanglements of free chains to enable polymeric functional programmability of the metamaterials on the macroscale. This macroscale polymeric programmability not only allows synthetic, nature-inspired strengthening combinations that are unattainable in microscale polymer networks, but also turns polymer-inspired metamaterials into a programmable experimental platform for exploring new deformation strengthening strategies, opening pathways to functional applications such as soft, humanoid-like tissues for robotic joints and compliant connectors. + oai:arXiv.org:2512.16732v1 + physics.app-ph + Fri, 19 Dec 2025 00:00:00 -0500 new - http://creativecommons.org/licenses/by/4.0/ - Juan Augusto Paredes Salazar, Ankit Goel, Rowen Costich, Meliksah Koca, Ozgur Tumuklu, Michael Amitay + http://arxiv.org/licenses/nonexclusive-distrib/1.0/ + Zhenyang Gao, Pengyuan Ren, Yifeng Dong, Gengchen Zheng, Min-Son Pham, Xiao Shang, Shaojia Wang, Shuo Yang, Zijue Tang, Yongbing Li, Hua Sun, Yi Wua, Hongjian Jiang, Lan Zhang, Tobin Filleter, Lingyu Kong, Kun Zhou, Haowei Wanga, Yang Lu, Yu Zou, Hongze Wang - qs$GW$ quasiparticle and $GW$-BSE excitation energies of 133,885 molecules - https://arxiv.org/abs/2512.10815 - arXiv:2512.10815v1 Announce Type: new -Abstract: Machine learning applications in the chemical sciences, especially when based on neural networks, critically depend on the availability of large quantities of high quality data. As they provide excellent accuracy for both charged and neutral excitations, a large dataset containing quasiparticle self-consistent GW (qs$GW$) and Bethe-Salpeter equation (BSE) data would be highly desirable to model excited state energies and properties. In this work, we introduce a dataset for qs$GW$-BSE excitation energies and qs$GW$ quasiparticle energies of unprecedented size. Our dataset, denoted QM9GWBSE, supplies $GW$-BSE singlet-singlet and singlet-triplet excitation energies, corresponding transition dipole moments and oscillator strengths as well as qs$GW$ quasiparticle energies for all molecules from the popular QM9 dataset. We anticipate that QM9GWBSE will provide a solid foundation to train highly accurate machine learning models for the prediction of molecular excited state properties. - oai:arXiv.org:2512.10815v1 - physics.chem-ph - Fri, 12 Dec 2025 00:00:00 -0500 + Automatic Penalty Parameter Selection by Residual Whiteness Principle (RWP) and GCV for Full Waveform Inversion + https://arxiv.org/abs/2512.16757 + arXiv:2512.16757v1 Announce Type: new +Abstract: Full-waveform inversion (FWI) is a powerful seismic imaging technique used to estimate high-resolution physical properties of subsurface structures by minimizing the misfit between observed and modeled seismic data. FWI is inherently a highly non-linear and ill-posed inverse problem. Extended-source approaches, such as the augmented Lagrangian (AL) method, are employed to improve solution convexity and robustness. A key component of this formulation is the penalty parameter, which controls the trade-off between data fitting and satisfaction of the wave-equation constraint, strongly influencing convergence in the presence of noise. The main challenge lies in selecting the penalty parameter. Traditional strategies such as the Discrepancy Principle (DP) require an accurate estimate of the noise level, which is often unknown or poorly characterized. Moreover, trial-and-error tuning requires repeatedly solving the inverse problem, making it computationally expensive. To overcome these limitations and develop a parameter-free, computationally efficient extended-source FWI algorithm, we integrate two data-driven parameter-selection strategies--the Residual Whiteness Principle (RWP) and a stable variant of Generalized Cross-Validation (RGCV)--within a multiplier-oriented AL framework. Specifically, we adopt a dual-space AL formulation, which allows the background wave-equation operator to remain fixed and requires only a single LU factorization per frequency, significantly improving efficiency. This design enables dynamic adjustment of the parameter at negligible cost during iterations, making the algorithm scalable for large-scale applications. Numerical experiments on acoustic and elastic FWI with white and colored noise show that, combined with the dual-space formulation, RWP provides strong noise robustness, resulting in a reliable automated solution for large-scale seismic inversion. + oai:arXiv.org:2512.16757v1 + physics.geo-ph + Fri, 19 Dec 2025 00:00:00 -0500 new http://creativecommons.org/licenses/by/4.0/ - Dario Baum, Arno F\"orster, Lucas Visscher + Kamal Aghazade, Toktam Zand, Ali Gholami - Cosmic Ray Measurements Using Charge and Light Readout in a Pixelated Liquid Argon Time Projection Chamber - https://arxiv.org/abs/2512.10830 - arXiv:2512.10830v1 Announce Type: new -Abstract: Liquid argon time projection chambers have emerged as a competitive technology for detecting solar neutrinos. The SoLAr collaboration was formed to explore argon detectors with pixelated light and charge readout, aiming for high detection efficiency and improved energy resolution. Building on the success of an initial prototype, we present results obtained with a second SoLAr prototype (V2), a $30 \times 30 \times 30$ cm$^{3}$ time projection chamber operated in a cryostat containing several hundred kilograms of liquid argon. We report measurements of cosmic-ray muons using both tracking and calorimetry from light and charge sensors, and we highlight the improved performance achieved through combined charge and light reconstruction. These results demonstrate the promise of dual-readout detectors and motivate future prototyping efforts toward kiloton-scale facilities. - oai:arXiv.org:2512.10830v1 + Operation of silicon photomultipliers in a dilution refrigerator down to 9.4 mK towards a cryogenic cosmic ray muon veto system + https://arxiv.org/abs/2512.16769 + arXiv:2512.16769v1 Announce Type: new +Abstract: We report the characterisation of a FBK NUV-HD-cryo silicon photomultiplier (SiPM) sensor operated in an 9.4 $\pm$ 0.2 mK environment inside a dilution refrigerator, towards the development of a cryogenic cosmic ray muon veto system to be operated internal to a dilution refrigerator required for low background experiments such as the QUEST-DMC dark matter search experiment. We characterise the single photon response and the gain (the charge produced per detected photon), the dark count noise rate, and correlated noise contributions as a function of operating voltage. This paper also reports first proof of concept measurements of using a SiPM directly coupled to scintillator in a 9.4 mK temperature environment, towards detecting candidate cosmic ray muon signals. + oai:arXiv.org:2512.16769v1 physics.ins-det hep-ex - Fri, 12 Dec 2025 00:00:00 -0500 + Fri, 19 Dec 2025 00:00:00 -0500 new http://creativecommons.org/licenses/by/4.0/ - SoLAr Collaboration, N. Anfimov, A. Branca, J. B\"urgi, L. Calivers, P. Carniti, E. Calvo, E. Cristaldo, C. Cuesta, F. Declich, R. Diurba, P. Dunne, D. A. Dwyer, J. Evans, A. C. Ezeribe, A. Gauch, I. Gil-Botella, C. Gotti, S. Greenberg, D. Guffanti, A. Karcher, J. Kunzmann, N. Lane, S. Manthey Corchado, N. McConkey, A. Minotti, A. Navrer-Agasson, S. Parsa, G. Pessina, G. Ruiz Ferreira, B. Russell, S. S\"oldner-Rembold, A. M. Szelc, A. Tapper, F. Terranova, C. Tognina, D. Trotta, S. Tufanli, H. Vieira de Souza, G. Vitti Stenico, A. Verdugo, M. Weber, I. Xiotidis - - - Basic requirements for potential differences across solid--fluid interfaces - https://arxiv.org/abs/2512.10859 - arXiv:2512.10859v1 Announce Type: new -Abstract: At model water--vapor and water--solid interfaces, molecular ordering leads to charge oscillations and, thereby, to a spatially varying electrostatic potential. Atomistic simulations indicate that such ordering leads to an electric potential difference $\chi$, the surface potential, of about $-0.5\,\mathrm{V}$ across the first few molecular layers. Here, we calculate surface potentials at interfaces between a simple model fluids and a solid, with Molecular Dynamics simulations. The fluids are made up of either diatomic, dipolar molecules or a single Lennard-Jones particle with a dipole moment. All fluids show some structuring near the interface, but charge oscillations and a non-zero surface potential are present only for asymmetric molecules (unequal diameters of the atoms) or molecules with an off-center dipole. We condense this finding into the criterion that the geometric and dipolar centers of a molecule must differ for the fluid to exhibit a surface potential. Remarkably, while the solid--fluid interaction strength strongly affects the magnitude of charge oscillations, it hardly affects the potential drop $\chi$. Further, our results demonstrate that changing the diameter of the smaller atom can flip the sign of the surface potential, thus highlighting the importance of steric effects. - oai:arXiv.org:2512.10859v1 - physics.chem-ph - Fri, 12 Dec 2025 00:00:00 -0500 - new - http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - David Fertig, Adrian L. Usler, Mathijs Janssen + DMC Collaboration, A. Kemp, S. Autti, E. Bloomfield, A. Casey, N. Darvishi, N. Eng, P. Franchini, R. P. Haley, P. J. Heikkinen, A. Jennings, S. Koulosousas, E. Leason, L. V. Levitin, J. March-Russell, A. Mayer, J. Monroe, D. M\"unstermann, M. T. Noble, J. R. Prance, X. Rojas, T. Salmon, J. Saunders, J. Smirnov, R. Smith, M. D. Thompson, A. Thomson, A. Ting, V. Tsepelin, S. M. West, L. Whitehead, D. E. Zmeev - Rapid multi-mode trapped-ion laser cooling in a phase-stable standing wave - https://arxiv.org/abs/2512.10900 - arXiv:2512.10900v1 Announce Type: new -Abstract: Laser cooling is fundamental to precise control and interrogation of atomic quantum systems. In the context of quantum computing and metrology with trapped ions, the integrated optical control of interest for scaling may additionally enable increased performance of coherent and incoherent operations. Here we utilize multi-channel integrated delivery of ultraviolet to infrared wavelengths required for calcium ion control including in passively phase-stable ultraviolet standing waves to demonstrate rapid, broadband laser cooling. We experimentally verify a long-standing prediction, realizing Doppler cooling to below the conventional Doppler limit at a standing-wave (SW) node. Utilizing electromagnetically induced transparency (EIT), we experimentally cool motional modes spanning an approximately 5 MHz bandwidth from the Doppler temperature to near the ground state within 150 $\mu$s, reaching $\bar n \approx 0.05$ phonon number occupancies for the target mode. Direct evaluation against the comparable running-wave (RW) scheme shows the SW implementation's simultaneous advantage in cooling rate, motional mode bandwidth, and final phonon number as previously theoretically predicted. Our results demonstrate structured light's capability for robust ground-state laser cooling, and a clear advantage in a fundamental functionality enabled by scalable approaches to optical control. - oai:arXiv.org:2512.10900v1 - physics.atom-ph + Model-Based Real-Time Synthesis of Acousto-Optically Generated Laser-Beam Patterns and Tweezer Arrays + https://arxiv.org/abs/2512.16774 + arXiv:2512.16774v1 Announce Type: new +Abstract: Acousto-optic deflectors (AOD) enable spatiotemporal control of laser beams through diffraction at an ultrasonic grating that is controllable by radio-frequency (rf) waveforms. These devices are a widely used tool for high-bandwidth random-access scanning applications, such as optical tweezers in quantum technology. A single AOD can generate multiple optical tweezers by multitone rf input in one dimension. Two-dimensional (2D) patterns can be realized with two perpendicularly oriented AODs. As the acousto-optical response depends nonlinearly on the applied frequency components, phases, and amplitudes, and in addition experiences dimensional coupling in 2D setups, intensity regulation becomes a unique challenge. Guided by coupled-wave theory and experimental observations, we derive a compute-efficient model which we implement on a graphics processing unit. Only one-time sampling of single-tone laser-power calibration is needed for model parameter determination, allowing for straight-forward integration into optical instruments. We implement and experimentally validate an open-loop diffraction efficiency control system that enables programmable 2D multibeam trajectories with intensity control applied at every time step during digital signal generation, overcoming the limited flexibility, pattern-size constraints, and bandwidth limitations of methods using precalculation and precalibration of a predefined pattern set or closed-loop feedback. The system is capable of stable real-time waveform streaming of arrays with up to 50 x 50 tweezers with minimal time resolution of 1.4 ns (700 MS/s) and a peak latency below 257 microseconds for execution of newly requested patterns. Reactive, real-time 2D multibeam laser patterning and scanning with strict intensity matching will substantially benefit parallelization and increasing data rates in materials processing, microscopy, and optical tweezers. + oai:arXiv.org:2512.16774v1 physics.optics quant-ph - Fri, 12 Dec 2025 00:00:00 -0500 + Fri, 19 Dec 2025 00:00:00 -0500 new http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Zhenzhong Xing, Hamim Mahmud Rivy, Vighnesh Natarajan, Aditya Milind Kolhatkar, Gillenhaal Beck, Karan K. Mehta + 10.1103/d3tx-3tg8 + Phys. Rev. Appl. vol.24, 064046 (2025) + Marcel Mittenbuehler, Lukas Sturm, Malte Schlosser, Gerhard Birkl - Fast generation of 3D flow obstacles from parametric surface models: application to cardiac valves - https://arxiv.org/abs/2512.09945 - arXiv:2512.09945v1 Announce Type: cross -Abstract: Due to the computationally demanding nature of fluid-structure interaction simulations, heart valve simulation is a complex task. A simpler alternative is to model the valve as a resistive flow obstacle that can be updated dynamically without altering the mesh, but this approach can also become computationally expensive for large meshes. - In this work, we present a fast method for computing the resistive flow obstacle of a heart valve. The method is based on a parametric surface model of the valve, which is defined by a set of curves. The curves are adaptively sampled to create a polyline representation, which is then used to generate the surface. The surface is represented as a set of points, allowing for efficient distance calculations to determine whether mesh nodes belong to the valve surface. We introduce three algorithms for computing these distances: minimization, sampling, and triangulation. Additionally, we implement two mesh traversal strategies: exhaustive node iteration and recursive neighbor search. The latter significantly reduces the number of distance calculations by only considering neighboring nodes. - Our pipeline is demonstrated on both a previously reported aortic valve model and a newly proposed mitral valve model, highlighting its flexibility and efficiency for rapid valve shape updates in computational simulations. - oai:arXiv.org:2512.09945v1 - q-bio.TO - physics.med-ph - Fri, 12 Dec 2025 00:00:00 -0500 - cross + Unraveling persistent urban-rural gaps: A long-term provincial analysis of residential heating and cooling loads + https://arxiv.org/abs/2512.16779 + arXiv:2512.16779v1 Announce Type: new +Abstract: With global climate change and rising demand for thermal comfort, space heating and cooling have become increasingly critical to achieving carbon neutrality in the building sector. This study presents a first attempt to develop a bottom-up regional building energy model based on prototype buildings simulated in EnergyPlus, to assess space heating and cooling loads of urban and rural residential buildings across 30 Chinese provinces from 1980 to 2024. The results indicate that: (1) Guangdong recorded the highest cooling loads in 2020, reaching 76.5 TWh/a in urban areas and 63.0 TWh/a in rural areas; Henan exhibited the highest rural heating load at 174.6 TWh/a, while urban heating loads were highest in provinces such as Liaoning and Shandong. (2) From 1980 to 2024, average cooling loads increased from 12.4 to 15.1 kWh/m2/a in urban areas but declined from 22.63 to 19.87 kWh/m2/a in rural areas. Over the same period, average heating loads decreased from 44.08 to 39.92 kWh/m2/a in urban areas and from 100.15 to 72.42 kWh/m2/a in rural areas. (3) Urban residential building stock has surpassed rural stock in 22 provinces in recent years, compared with only 4 provinces in 2000, and the presence of 12 urban energy-efficiency standards versus only one rural standard further highlights substantial envelope performance gaps. Collectively, these dynamics have led to pronounced and persistent urban-rural disparities in residential heating and cooling loads. These findings underscore the need for differentiated standards and region-specific clean heating strategies, while providing a transferable modeling framework to inform targeted energy-saving policies and support the building sector's transition toward carbon neutrality. + oai:arXiv.org:2512.16779v1 + physics.soc-ph + Fri, 19 Dec 2025 00:00:00 -0500 + new http://creativecommons.org/licenses/by/4.0/ - Bob van der Vuurst, Ji\v{r}\'i Kosinka, Crist\'obal Bertoglio + Qinwen Tang, Ran Yan, Nan Zhou, Minda Ma - Quantum Monte Carlo in Classical Phase Space with the Wigner-Kirkwood Commutation Function. Results for the Saturation Liquid Density of $^4$He - https://arxiv.org/abs/2512.09948 - arXiv:2512.09948v1 Announce Type: cross -Abstract: A Metropolis Monte Carlo algorithm is given for the case of a complex phase space weight, which applies generally in quantum statistical mechanics. Computer simulations using Lennard-Jones $^4$He near the $\lambda$-transition, including an expansion to third order of the Wigner-Kirkwood commutation function, give a saturation liquid density in agreement with measured values. - oai:arXiv.org:2512.09948v1 - cond-mat.stat-mech - cond-mat.quant-gas - physics.comp-ph - quant-ph - Fri, 12 Dec 2025 00:00:00 -0500 - cross + Topology of the near field in enhanced transmission through subwavelength apertures + https://arxiv.org/abs/2512.16785 + arXiv:2512.16785v1 Announce Type: new +Abstract: We analyze enhanced optical transmission through subwavelength aper- tures using a modal formulation for the two fundamental polarizations, transverse electric (TE) and transverse magnetic (TM). Within this frame- work, the fields inside the aperture are described in terms of guided modes whose excitation and interference govern the transmission process. By ex- amining the near-field energy transport through the time-averaged Poynt- ing vector, we show that resonant transmission is accompanied by a pro- nounced reorganization of the energy flow in the vicinity of the aperture. As the wavelength is varied across resonance, the energy transport un- dergoes a topological transition characterized by vortical and saddle-type flow structures, localized backflow regions, and efficient energy funneling through the aperture. These features correlate with strong phase gradi- ents and phase singularities associated with the excited modal fields. The modal approach provides a unified and physically transparent interpre- tation of enhanced transmission in both slits and channels, applicable to perfect conductors and beyond plasmonic regimes. + oai:arXiv.org:2512.16785v1 + physics.optics + Fri, 19 Dec 2025 00:00:00 -0500 + new http://creativecommons.org/licenses/by/4.0/ - Phil Attard + MA Ortiz-Ferreyro, J. Sumaya-Martinez, A. Esquivel-Navarrete - Hybrid Finite Element and Least Squares Support Vector Regression Method for solving Partial Differential Equations with Legendre Polynomial Kernels - https://arxiv.org/abs/2512.09967 - arXiv:2512.09967v1 Announce Type: cross -Abstract: A hybrid computational approach that integrates the finite element method (FEM) with least squares support vector regression (LSSVR) is introduced to solve partial differential equations. The method combines FEM's ability to provide the nodal solutions and LSSVR with higher-order Legendre polynomial kernels to deliver a closed-form analytical solution for interpolation between the nodes. The hybrid approach implements element-wise enhancement (super-resolution) of a given numerical solution, resulting in high resolution accuracy, while maintaining consistency with FEM nodal values at element boundaries. It can adapt any low-order FEM code to obtain high-order resolution by leveraging localized kernel refinement and parallel computation without additional implementation overhead. Therefore, effective inference/post-processing of the obtained super-resolved solution is possible. Evaluation results show that the hybrid FEM-LSSVR approach can achieve significantly higher accuracy compared to the base FEM solution. Comparable accuracy is a achieved when comparing the hybrid solution with a standalone FEM result with the same polynomial basis function order. The convergence studies were conducted for four elliptic boundary value problems to demonstrate the method's ability, accuracy, and reliability. Finally, the algorithm can be directly used as a plug-and-play method for super-resolving low-order numerical solvers and for super-resolution of expensive/under-resolved experimental data. - oai:arXiv.org:2512.09967v1 - math.NA - cs.NA - physics.comp-ph - Fri, 12 Dec 2025 00:00:00 -0500 - cross - http://creativecommons.org/publicdomain/zero/1.0/ - Maryam Babaei, Peter Rucz, Manfred Kaltenbacher, Stefan Schoder + Evaluation of a large-area double-sided silicon strip detector for quality assurance in ion-beam radiotherapy + https://arxiv.org/abs/2512.16789 + arXiv:2512.16789v1 Announce Type: new +Abstract: Designed to provide quality assurance for ion-beam radiotherapy, the prototype fIVI (filtered Interaction Vertex Imaging) Range Monitoring System is a two-layer tracker which employs double-sided strip-segmented silicon detectors. To meet the high demands of a clinical environment, a large sensitive area is required, along with a fast and compact readout. As this device utilizes sensors and readout electronics adapted from particle physics, where the expected energy and count rate differ significantly from radiotherapy, validation was necessary to ensure that these sensors would function effectively at the order 100 MeV/u energies and order MHz count rates expected during clinical irradiation. Tests were conducted using scattered subclinical 19 MeV protons at high intensity, and clinical 207 MeV/u carbon ions at low intensity to independently validate these variables. The detection system is found to operate at rates up to 1.3 MHz, with a negligible fraction of events being affected by pileup. The efficiency of hit reconstruction is high, with a timestamp resolution of 6.25 ns, and a coincidence window of 31.25 ns, as is required for clinical event rates. With these settings, over 90% of particle interactions are able to reconstruct unique hit positions and contribute to track formation. This device is the first system using large-area, high-resolution detectors which meets the demanding count rate requirements associated with clinical radiotherapy. + oai:arXiv.org:2512.16789v1 + physics.ins-det + physics.med-ph + Fri, 19 Dec 2025 00:00:00 -0500 + new + http://arxiv.org/licenses/nonexclusive-distrib/1.0/ + Devin Hymers (Institute for Nuclear Physics, University of Cologne, Cologne, Germany), Sebastian Schroeder (Institute for Nuclear Physics, University of Cologne, Cologne, Germany), Olga Bertini (GSI GmbH, Darmstadt, Germany), Johann Heuser (GSI GmbH, Darmstadt, Germany), Joerg Lehnert (GSI GmbH, Darmstadt, Germany), Christian Joachim Schmidt (GSI GmbH, Darmstadt, Germany), Dennis M\"ucher (Institute for Nuclear Physics, University of Cologne, Cologne, Germany) - Clues from $\mathcal{Q}$--A null test designed for line intensity mapping cross-correlation studies - https://arxiv.org/abs/2512.09984 - arXiv:2512.09984v1 Announce Type: cross -Abstract: Estimating the auto power spectrum of cosmological tracers from line-intensity mapping (LIM) data is often limited by instrumental noise, residual foregrounds, and systematics. Cross-power spectra between multiple lines offer a robust alternative, mitigating noise bias and systematics. However, inferring the auto spectrum from cross-correlations relies on two key assumptions: that all tracers are linearly biased with respect to the matter density field, and that they are strongly mutually correlated. In this work, we introduce a new diagnostic statistic, \(\mathcal{Q}\), which serves as a data-driven null test of these assumptions. Constructed from combinations of cross-spectra between four distinct spectral lines, \(\mathcal{Q}\) identifies regimes where cross-spectrum-based auto-spectrum reconstruction is unbiased. We validate its behavior using both analytic toy models and simulations of LIM observables, including star formation lines ([CII], [NII], [CI],[OIII]) and the 21-cm signal. We explore a range of redshifts and instrumental configurations, incorporating noise from representative surveys. Our results demonstrate that the criterion \( \mathcal{Q} \approx 1 \) reliably selects the modes where cross-spectrum estimators are valid, while significant deviations are an indicator that the key assumptions have been violated. The \( \mathcal{Q} \) diagnostic thus provides a simple yet powerful data-driven consistency check for multi-tracer LIM analyses. - oai:arXiv.org:2512.09984v1 - astro-ph.CO - astro-ph.IM + Applying Gaussian Mixture Models to Track Reconstruction in Inelastic Scattering Experiments with Active Targets + https://arxiv.org/abs/2512.16794 + arXiv:2512.16794v1 Announce Type: new +Abstract: Active targets such as ACTAR TPC are well suited for studying giant resonances in unstable nuclei via inelastic scattering in inverse kinematics. A key challenge in such measurements is the detection of low-energy ejectiles emitted at small angles relative to the beam direction. Accurate reconstruction of these tracks is essential for disentangling different resonance modes. Probabilistic models such as the Gaussian Mixture Model (GMM) are particularly effective in capturing the complex covariance structures characteristic of the beam-recoil interface in narrow-angle events. In this work, we present a track reconstruction approach based on the GMM, specifically designed for inelastic scattering experiments with active targets. Special emphasis is placed on the treatment of low-energy tracks. The proposed method is demonstrated on simulated data of the $^{58}\mathrm{Ni}(\alpha,\alpha')^{58}\mathrm{Ni}$ reaction at an incident energy of $E=49$~MeV/nucleon, generated under conditions representative of the experiment carried out at GANIL for the same reaction. + oai:arXiv.org:2512.16794v1 physics.data-an - Fri, 12 Dec 2025 00:00:00 -0500 - cross - http://creativecommons.org/licenses/by-nc-nd/4.0/ - Debanjan Sarkar, Ella Iles, Adrian Liu - - - Fluctuation-induced giant magnetoresistance in charge-neutral graphene - https://arxiv.org/abs/2512.09988 - arXiv:2512.09988v1 Announce Type: cross -Abstract: The Johnson-Nyquist noise associated with the intrinsic conductivity of the electron liquid, induces fluctuations of the electron density in charge-neutral graphene devices. In the presence of external electric and magnetic fields, the fluctuations of charge density and electric current induce a fluctuating hydrodynamic flow. We show that the resulting advection of charge produces a fluctuation contribution to the macroscopic conductivity of the system, $\sigma_{\mathrm{fl}}$, and develop a quantitative theory of $\sigma_{\mathrm{fl}}$. At zero magnetic field, $\sigma_{\mathrm{fl}}$ diverges logarithmically with the system size and becomes rapidly suppressed at relatively small fields. This results in giant magnetoresistance of the system. - oai:arXiv.org:2512.09988v1 - cond-mat.mes-hall - physics.flu-dyn - Fri, 12 Dec 2025 00:00:00 -0500 - cross + nucl-ex + Fri, 19 Dec 2025 00:00:00 -0500 + new http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - A. Levchenko, E. Kirkinis, A. V. Andreev - - - Searches for electroweak states at future plasma wakefield colliders - https://arxiv.org/abs/2512.09995 - arXiv:2512.09995v1 Announce Type: cross -Abstract: We quantify the discovery potential of future multi-TeV plasma wakefield colliders for new electroweak multiplets. We include beam-beam effects through realistic luminosity spectra, comparing five collider configurations: $e^+e^-$ and $e^-e^-$ machines with round- and flat-beams, and a $\gamma\gamma$ collider. The beam-beam effects qualitatively change search strategies relative to idealized mono-energetic lepton colliders, highlighting the importance of the low-energy part of the luminosity spectrum and additional beam-induced initial-state channels. Our results have implications for accelerator R&D priorities, since key electroweak targets may remain accessible even if efficient positron acceleration and flat-beam delivery prove technically challenging at the multi-TeV scale. - oai:arXiv.org:2512.09995v1 - hep-ph - physics.acc-ph - Fri, 12 Dec 2025 00:00:00 -0500 - cross - http://creativecommons.org/licenses/by/4.0/ - So Chigusa, Simon Knapen, Toby Opferkuch, Inbar Savoray, Christiane Scherb, Weishuang Linda Xu - - - Broadband Spatio-Spectral Mode Conversion via Four-Wave Mixing - https://arxiv.org/abs/2512.10045 - arXiv:2512.10045v1 Announce Type: cross -Abstract: We introduce a framework for scalable and broadband free-space phase-matched four-wave mixing in ring resonators. This method for four-wave mixing reduces the complexity of coupling an emitter to a quantum network by combining the spatial and spectral interfaces between them into one nonlinear optical process. The device is compliant with current heterogeneous integration capabilities and has a bandwidth of 165 nm for efficient spatio-spectral conversion. We outline a fabrication-ready diamond-on-insulator pathway towards modular unit cells that natively bridge visible color centers to the infrared spectrum for scalable quantum networks. We also present and analyze an end-to-end framework for considering single-photon coupling efficiency from a color center to a quantum network. This framework represents a step forwards in analyzing and reducing system-scale losses in a spin-photon interface. - oai:arXiv.org:2512.10045v1 - quant-ph - physics.app-ph - physics.optics - Fri, 12 Dec 2025 00:00:00 -0500 - cross - http://creativecommons.org/licenses/by/4.0/ - Helaman Flores, Mahmoud Jalali Mehrabad, Siavash Mirzaei-Ghormish, Ryan M. Camacho, Dirk Englund + A. Arokiaraj, M. B. Latif, R. Raabe, D. Thisse, M. Vandebrouck - Detailed balance in large language model-driven agents - https://arxiv.org/abs/2512.10047 - arXiv:2512.10047v1 Announce Type: cross -Abstract: Large language model (LLM)-driven agents are emerging as a powerful new paradigm for solving complex problems. Despite the empirical success of these practices, a theoretical framework to understand and unify their macroscopic dynamics remains lacking. This Letter proposes a method based on the least action principle to estimate the underlying generative directionality of LLMs embedded within agents. By experimentally measuring the transition probabilities between LLM-generated states, we statistically discover a detailed balance in LLM-generated transitions, indicating that LLM generation may not be achieved by generally learning rule sets and strategies, but rather by implicitly learning a class of underlying potential functions that may transcend different LLM architectures and prompt templates. To our knowledge, this is the first discovery of a macroscopic physical law in LLM generative dynamics that does not depend on specific model details. This work is an attempt to establish a macroscopic dynamics theory of complex AI systems, aiming to elevate the study of AI agents from a collection of engineering practices to a science built on effective measurements that are predictable and quantifiable. - oai:arXiv.org:2512.10047v1 - cs.LG - cond-mat.stat-mech - cs.AI - nlin.AO - physics.data-an - Fri, 12 Dec 2025 00:00:00 -0500 - cross + Clinical beam test of inter- and intra-fraction relative range monitoring in carbon ion radiotherapy + https://arxiv.org/abs/2512.16798 + arXiv:2512.16798v1 Announce Type: new +Abstract: Interaction Vertex Imaging (IVI) is used for range monitoring (RM) in carbon ion radiotherapy. The purpose of RM is to measure the Bragg peak (BP) position for each contributing beam, and detect any changes. Currently, there is no consensus on a clinical RM method, the use of which would improve the safety and consistency of treatment. The prototype filtered IVI (fIVI) Range Monitoring System is the first system to apply large-area and high-rate-capable silicon detectors to IVI. Two layers of these detectors track prompt secondary fragments for use in RM. This device monitored 16 cm and 32 cm diameter cylindrical plastic phantoms irradiated by clinical carbon ion beams at the Heidelberg Ion Beam Therapy Center. Approximately 20 different BP depths were delivered to each phantom, with a minimum depth difference of 0.8 mm and a maximum depth difference of 51.9 mm and 82.5 mm respectively. For large BP range differences, the relationship between the true depth difference and that measured by fIVI is quadratic, although for small differences, the deviation from a linear relationship with a slope of 1 is negligible. RM performance is strongly dependent on the number of tracked particles, particularly in the clinically-relevant regime. Significant performance differences exist between the two phantoms, with millimetric precision at clinical doses being achieved only for the 16 cm phantom. The performance achieved by the prototype fIVI Range Monitoring System is consistent with previous investigations of IVI, despite measuring at more challenging shallow BP positions. Further significant improvements are possible through increasing the sensitive area of the tracking system beyond the prototype, which will both allow an improvement in precision for the most intense points of a scanned treatment plan and expand the number of points for which millimetric precision may be achieved. + oai:arXiv.org:2512.16798v1 + physics.med-ph + Fri, 19 Dec 2025 00:00:00 -0500 + new http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Zhuo-Yang Song, Qing-Hong Cao, Ming-xing Luo, Hua Xing Zhu + Devin Hymers (Institute for Nuclear Physics, University of Cologne, Cologne, Germany), Sebastian Schroeder (Institute for Nuclear Physics, University of Cologne, Cologne, Germany), Olga Bertini (GSI GmbH, Darmstadt, Germany), Stephan Brons (Heidelberg Ion Beam Therapy Centre), Johann Heuser (GSI GmbH, Darmstadt, Germany), Joerg Lehnert (GSI GmbH, Darmstadt, Germany), Christian Joachim Schmidt (GSI GmbH, Darmstadt, Germany), Dennis M\"ucher (Institute for Nuclear Physics, University of Cologne, Cologne, Germany) + + + A parallel, pipeline-based online analysis system for Interaction Vertex Imaging + https://arxiv.org/abs/2512.16800 + arXiv:2512.16800v1 Announce Type: new +Abstract: Objective + Interaction vertex imaging (IVI) is used for range monitoring in carbon ion radiotherapy, detecting depth differences between Bragg peak positions. Online range monitoring, which provides feedback during beam delivery, is particularly desirable, creating an opportunity to detect range errors before the treatment fraction is completed. Incorporating online range monitoring into clinical workflows may therefore improve the safety and consistency of radiotherapy. + Approach + The data analysis system was broken into a task-parallel pipeline approach, to allow multiple analysis stages to occur concurrently, beginning during acquisition. Computationally-expensive operations were further parallelized to reduce bottleneck effects. Data collected from irradiation of homogeneous plastic phantoms was replayed at the same rate it was initially acquired, to mimic data acquisition, and the time required to determine a range shift was measured. + Main Results + With an optimized pipeline, the delay between the end of irradiation and the determination of a range shift is consistently less than 200 ms. The majority of this time is associated with the final range shift determination, with a minor effect from the time required to analyze the last data packet. The most significant contribution to an optimized analysis workflow is the formation of clusters, requiring almost 50% of compute time. + Significance + This system is the first IVI implementation to achieve clinically-relevant online analysis times. The 200 ms time required to determine a range shift is less than the time required to accelerate a new spill in a synchrotron, and is comparable to the time required for reacceleration if multiple energies are delivered in the same spill. Clinical implementation of online range monitoring would allow treatment to be quickly paused or aborted if significant range errors are detected. + oai:arXiv.org:2512.16800v1 + physics.med-ph + Fri, 19 Dec 2025 00:00:00 -0500 + new + http://arxiv.org/licenses/nonexclusive-distrib/1.0/ + Devin Hymers (Institute for Nuclear Physics, University of Cologne, Cologne, Germany), Sebastian Schroeder (Institute for Nuclear Physics, University of Cologne, Cologne, Germany), Olga Bertini (GSI GmbH, Darmstadt, Germany), Johann Heuser (GSI GmbH, Darmstadt, Germany), Joerg Lehnert (GSI GmbH, Darmstadt, Germany), Christian Joachim Schmidt (GSI GmbH, Darmstadt, Germany), Dennis M\"ucher (Institute for Nuclear Physics, University of Cologne, Cologne, Germany) - A Primer on Bayesian Parameter Estimation and Model Selection for Battery Simulators - https://arxiv.org/abs/2512.10055 - arXiv:2512.10055v1 Announce Type: cross -Abstract: Physics-based battery modelling has emerged to accelerate battery materials discovery and performance assessment. Its success, however, is still hindered by difficulties in aligning models to experimental data. Bayesian approaches are a valuable tool to overcome these challenges, since they enable prior assumptions and observations to be combined in a principled manner that improves numerical conditioning. Here we introduce two new algorithms to the battery community, SOBER and BASQ, that greatly speed up Bayesian inference for parameterisation and model comparison. We showcase how Bayesian model selection allows us to tackle data observability, model identifiability, and data-informed model development together. We propose this approach for the search for battery models of novel materials. - oai:arXiv.org:2512.10055v1 + The Colombian legislative process, 2014-2025: networks, topics, and polarization + https://arxiv.org/abs/2512.16827 + arXiv:2512.16827v1 Announce Type: new +Abstract: The legislative output of Colombia's House of Representatives between 2014 and 2025 is analyzed using 4,083 bills. Bipartite networks are constructed between parties and bills, and between representatives and bills, along with their projections, to characterize co-sponsorship patterns, centrality, and influence, and to assess whether political polarization is reflected in legislative collaboration. In parallel, the content of the initiatives is studied through semantic networks based on co-occurrences extracted from short descriptions, and topics by party and period are identified using a stochastic block model for weighted networks, with additional comparison using Latent Dirichlet Allocation. In addition, a Bayesian sociability model is applied to detect terms with robust connectivity and to summarize discursive cores. Overall, the approach integrates relational and semantic structure to describe thematic shifts across administrations, identify influential actors and collectives, and provide a reproducible synthesis that promotes transparency and citizen oversight of the legislative process. + oai:arXiv.org:2512.16827v1 + physics.soc-ph + stat.CO stat.ME - physics.data-an - stat.AP - Fri, 12 Dec 2025 00:00:00 -0500 - cross + Fri, 19 Dec 2025 00:00:00 -0500 + new http://creativecommons.org/licenses/by/4.0/ - Yannick Kuhn, Masaki Adachi, Micha Philipp, David A. Howey, Birger Horstmann - - - Efficient Boys function evaluation using minimax approximation - https://arxiv.org/abs/2512.10059 - arXiv:2512.10059v1 Announce Type: cross -Abstract: We present an algorithm for efficient evaluation of Boys functions $F_0,\dots,F_{k_\mathrm{max}}$ tailored to modern computing architectures, in particular graphical processing units (GPUs), where maximum throughput is high and data movement is costly. The method combines rational minimax approximations with upward and downward recurrence relations. The non-negative real axis is partitioned into three regions, $[0,\infty\rangle = A\cup B\cup C$, where regions $A$ and $B$ are treated using rational minimax approximations and region $C$ by an asymptotic approximation. This formulation avoids lookup tables and irregular memory access, making it well suited hardware with high maximum throughput and low latency. The rational minimax coefficients are generated using the rational Remez algorithm. For a target maximum absolute error of $\varepsilon_\mathrm{tol} = 5\cdot10^{-14}$, the corresponding approximation regions and coefficients for Boys functions $F_0,\dots,F_{32}$ are provided in the appendix. - oai:arXiv.org:2512.10059v1 - math.NA - cs.NA - physics.comp-ph - Fri, 12 Dec 2025 00:00:00 -0500 - cross - http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Rasmus Vikhamar-Sandberg, Michal Repisky + Juan Sosa, Brayan Riveros, Emma J. Camargo-D\'iaz - Enabling searches for long-lived particles at a future 10 TeV Muon Collider - https://arxiv.org/abs/2512.10097 - arXiv:2512.10097v1 Announce Type: cross -Abstract: Muon Colliders offer fantastic opportunities to explore new phenomena at the energy frontier. However, beam-induced-backgrounds from muon decays pose significant challenges for detector design, readout, and reconstruction. Previous detector studies have employed stringent hit-timing requirements to reduce occupancy to manageable levels with negligible efficiency loss for prompt Standard Model particles. In the spirit of maximizing discovery potential, we investigate the capability of detecting meta-stable charged long-lived particles at a 10 TeV Muon Collider. As a benchmark, we consider a Gauge Mediated Supersymmetry Breaking (GMSB) model in which the stau is long-lived and can be identified as a high momentum, slowly moving track. We find that nominal hit-timing selections are too restrictive, and investigate the impact of looser requirements. We demonstrate that it is possible to recover sensitivity to particles with masses close to $\sqrt{s}/2$ by expanding time acceptance, and provide recommendations to further improve tracker design and track reconstruction. - oai:arXiv.org:2512.10097v1 - hep-ex - physics.ins-det - Fri, 12 Dec 2025 00:00:00 -0500 - cross + Rayleigh-B\'enard thermal convection in emulsions: a short review + https://arxiv.org/abs/2512.16830 + arXiv:2512.16830v1 Announce Type: new +Abstract: Thermally driven emulsions arise in a broad range of natural and industrial contexts, yet their fundamental physical understanding remains only partially established. Emulsions exhibit a complex, concentration-dependent rheology, ranging from Newtonian (dilute emulsions) to yield-stress (concentrated emulsions). In buoyancy-driven flows, the complex structure and rheology of the emulsion are strongly coupled to convective flows, giving rise to fascinating and non-trivial phenomena involving stability, transient dynamics, and morphological evolution of the system. We review recent progress on thermally driven emulsions in the celebrated Rayleigh-B\'enard configuration, offering new perspectives on the behaviour of soft materials in thermal convection. + oai:arXiv.org:2512.16830v1 + physics.flu-dyn + Fri, 19 Dec 2025 00:00:00 -0500 + new http://creativecommons.org/licenses/by/4.0/ - Mira Littmann, Mark Larson, Benjamin Rosser, Tate Flicker, Kane Huang, Leo Rozanov, Karri Folan Di Petrillo + Francesca Pelusi, Andrea Scagliarini, Mauro Sbragaglia, Massimo Bernaschi, Roberto Benzi - Harnessing Vacuum Fluctuations to Shape Electronic and Photonic Behavior - https://arxiv.org/abs/2512.10145 - arXiv:2512.10145v1 Announce Type: cross -Abstract: Vacuum quantum fluctuations are an inescapable and fundamental feature of modern physics. By integrating cavity-enhanced or surface-modified vacuum quantum fluctuations with low-dimensional materials, a new paradigm-vacuumronics-emerges, enabling unprecedented control over both material properties and photonic responses at the micro- and nanoscale. This synergy opens novel pathways for engineering quantum light-matter interactions, advancing applications in quantum photonics, nanoscale optoelectronics, and quantum material design. - oai:arXiv.org:2512.10145v1 - cond-mat.mes-hall + Experimental Measurement of Enhanced Group Delay Silicon Photonic Waveguides Indicative of the Frozen Mode Regime Around the Stationary Inflection Point + https://arxiv.org/abs/2512.16831 + arXiv:2512.16831v1 Announce Type: new +Abstract: The dispersion engineering of periodic silicon photonic waveguides presents opportunities for significant group delay enhancement compared to uniform waveguides of comparable length. We describe the spectral response characteristics for measured devices and compare their properties to modeled data. These waveguides support the frozen mode regime (FMR) around near infrared wavelengths and are expected to show enhanced group delays around the FMR resonances. Measurements of fabricated devices provide evidence for enhanced delays and spectral properties associated with the FMR. We study how perturbations to the waveguide model impact agreement with measurements and its meaning for these devices operating in the FMR. + oai:arXiv.org:2512.16831v1 physics.optics - Fri, 12 Dec 2025 00:00:00 -0500 - cross + Fri, 19 Dec 2025 00:00:00 -0500 + new http://creativecommons.org/licenses/by/4.0/ - 10.1038/s44310-025-00091-4 - npj Nanophotonics 2, 46 (2025) - Qing-Dong Jiang + Nathaniel Furman, Albert Herrero-Parareda, Anthony Rapp, Ilya Vitebskiy, Ricky Gibson, Bradley J. Thompson, Dean P. Brown, Robert Bedford, Filippo Capolino - Optical fuse based on the photorefractive effect for defending the light-injection attacks of quantum key distribution - https://arxiv.org/abs/2512.10205 - arXiv:2512.10205v1 Announce Type: cross -Abstract: Light-injection attacks pose critical security threats to quantum key distribution (QKD) systems. Conventional defense methods, such as isolators, filters, and optical power monitoring, are confronted with the threats of specific attacks and the limitations in integration. To address this, we propose and experimentally demonstrate an integrated attack sensing and automatic response unit utilizing the photorefractive effect in a thin-film lithium niobate microring resonator. Our unit provides a high rejection ratio against non-resonant injected light. For resonant attacks exceeding tens of microwatts, the unit can autonomously attenuate the transmission of the quantum signal light, leading to a significant suppression of the secret key rate. This work enhances the security of QKD systems against light-injection attacks by providing a highly sensitive, broadband, and on-chip defense mechanism. - oai:arXiv.org:2512.10205v1 - quant-ph - physics.optics - Fri, 12 Dec 2025 00:00:00 -0500 - cross - http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Min Chen, Hong-Yan Song, Jia-Lin Chen, Peng Ye, Guo-Wei Zhang, Fang-Xiang Wang, Li Zhang, Shuang Wang, De-Yong He, Zhen-qiang Yin, Guang-Can Guo, Wei Chen, Zheng-Fu Han - - - Balancing the Byline: Exploring Gender and Authorship Patterns in Canadian Science Publishing Journals - https://arxiv.org/abs/2512.10268 - arXiv:2512.10268v1 Announce Type: cross -Abstract: Canada is internationally recognized for its leadership in science and its commitment to equity, diversity, and inclusion (EDI) in STEM (science, technology, engineering, and math) fields. Despite this leadership, limited research has examined gender disparities in scientific publishing within the Canadian context. This study analyzes over 67,000 articles published in 24 Canadian Science Publishing (CSP) journals between 2010 and 2021 to better understand patterns of gender representation. Findings show that women accounted for less than one-third of published authors across CSP journals. Representation varied by discipline, with higher proportions of women in biomedical sciences and lower proportions of women in engineering - trends that mirror broader national and global patterns. Notably, the proportion of women submitting manuscripts closely matched those published, suggesting that broader workforce disparities may play a larger role than publication bias. Women were less likely to be solo authors or to hold prominent authorship positions, such as first or last author - roles typically associated with research leadership and career advancement. These findings point to the need for a two-fold response: continued efforts to address systemic barriers to women's participation in science, and a review of publishing practices to ensure equitable access, recognition, and inclusion for all researchers. - oai:arXiv.org:2512.10268v1 - cs.DL + Enhancing Kinematics Understanding Through a Real-Time Graph-Based Motion Video Game + https://arxiv.org/abs/2512.16838 + arXiv:2512.16838v1 Announce Type: new +Abstract: Kinematics is a core topic in early physics courses, yet students often struggle to interpret motion and its graphical representations. To tackle these difficulties, we developed MissionMotion, a physical-computational videogame where students reproduce target motion graphs using real-time data from their own movements or from sensors connected through micro:bit or Arduino. The system displays both the target and the user-generated graph, providing immediate visual feedback and a score based on similarity. We piloted the environment with ninth-grade students in different school contexts and evaluated their experience using the MEEGA+ instrument. The results show strong engagement, positive perceptions of usability, and evidence that the game promotes reflection on motion graphs in ways that rarely emerge in traditional lessons. MissionMotion runs on any web-enabled device and all materials are openly available, offering teachers an accessible tool to integrate experimentation, computational thinking, and playful learning into physics classrooms. + oai:arXiv.org:2512.16838v1 physics.ed-ph - physics.soc-ph - Fri, 12 Dec 2025 00:00:00 -0500 - cross - http://creativecommons.org/licenses/by-nc-nd/4.0/ - Eden J. Hennessey, Amanda Desnoyers, Margaret Christ, Adrianna Tassone, Skye Hennessey, Bianca Dreyer, Alex Jay, Patricia Sanchez, Shohini Ghose + Fri, 19 Dec 2025 00:00:00 -0500 + new + http://arxiv.org/licenses/nonexclusive-distrib/1.0/ + Mateo Dutra, Marcos Abreu, Mart\'in Monteiro, Silvia Sguilla, Cecilia Stari, Alvaro Suarez, Arturo C. Marti - Quantum relaxometry for detecting biomolecular interactions with single NV centers - https://arxiv.org/abs/2512.10269 - arXiv:2512.10269v1 Announce Type: cross -Abstract: The investigation of biomolecular interactions at the single-molecule level has emerged as a pivotal research area in life science, particularly through optical, mechanical, and electrochemical approaches. Spins existing widely in biological systems, offer a unique degree of freedom for detecting such interactions. However, most previous studies have been largely confined to ensemble-level detection in the spin degree. Here, we developed a molecular interaction analysis method approaching single-molecule level based on relaxometry using the quantum sensor, nitrogen-vacancy (NV) center in diamond. Experiments utilized an optimized diamond surface functionalized with a polyethylenimine nanogel layer, achieving $\sim$10 nm average protein distance and mitigating interfacial steric hindrance. Then we measured the strong interaction between streptavidin and spin-labeled biotin complexes, as well as the weak interaction between bovine serum albumin and biotin complexes, at both the micrometer scale and nanoscale. For the micrometer-scale measurements using ensemble NV centers, we re-examined the often-neglected fast relaxation component and proposed a relaxation rate evaluation method, substantially enhancing the measurement sensitivity. Furthermore, we achieved nanoscale detection approaching single-molecule level using single NV centers. This methodology holds promise for applications in molecular screening, identification and kinetic studies at the single-molecule level, offering critical insights into molecular function and activity mechanisms. - oai:arXiv.org:2512.10269v1 - quant-ph - physics.bio-ph - Fri, 12 Dec 2025 00:00:00 -0500 - cross + A MAPS Detector for High Resolution Low Dose EBSD + https://arxiv.org/abs/2512.16839 + arXiv:2512.16839v1 Announce Type: new +Abstract: The use of highly sensitive pixelated direct detectors has dramatically improved the performance of high energy instrumentation such as transmission electron microscopy. Here, we describe a recently developed monolithic active pixel sensor designed for low energy scanning electron microscopy applications. This detector enables electron backscatter diffraction (EBSD) at lower energies and dose than are accessible with existing scintillator-coupled detectors, expanding grain orientation mapping capabilities to materials such as ceramics that are poor electron conductors. The high detector sensitivity allows collection of rich diffraction information - providing dislocation defect contrast that is otherwise not accessible via EBSD. Indeed, even the energy of single electron interaction events can be measured with this detector, which we demonstrate to energy filter diffraction patterns revealing details of how diffraction occurs at low energy. + oai:arXiv.org:2512.16839v1 + physics.ins-det + cond-mat.mes-hall + cond-mat.mtrl-sci + Fri, 19 Dec 2025 00:00:00 -0500 + new http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - 10.1073/pnas.2509102122 - PNAS 122 (35) e2509102122 (2025) - Min Li, Qi Zhang, Xi Kong, Sheng Zhao, Bin-Bin Pan, Ziting Sun, Pei Yu, Zhecheng Wang, Mengqi Wang, Wentao Ji, Fei Kong, Guanglei Cheng, Si Wu, Ya Wang, Sanyou Chen, Xun-Cheng Su, Fazhan Shi + B.D.A. Levin et al. A MAPS Detector for High Resolution Low Dose EBSD, Microscopy and Analysis, 39(4), 28-30, October 2025 + Barnaby D. A. Levin, Kalani Moore, Nicol\`o M. Della Ventura, McLean P. Echlin, Tresa M. Pollock, Daniel S. Gianola - Single-molecule Scale Nuclear Magnetic Resonance Spectroscopy using a Robust Near-Infrared Spin Sensor - https://arxiv.org/abs/2512.10278 - arXiv:2512.10278v1 Announce Type: cross -Abstract: Nuclear magnetic resonance (NMR) at the single-molecule level with atomic resolution holds transformative potential for structural biology and surface chemistry. Near-surface solid-state spin sensors with optical readout ability offer a promising pathway toward this goal. However, their extreme proximity to target molecules demands exceptional robustness against surface-induced perturbations. Furthermore, life science applications require these sensors to operate in biocompatible spectral ranges that minimize photodamage. In this work, we demonstrate that the PL6 quantum defect in 4H silicon carbide (4H-SiC) can serve as a robust near-infrared spin sensor. This sensor operates at tissue-transparent wavelengths and exhibits exceptional near-surface stability even at depth of 2 nm. Using shallow PL6 centers, we achieve nanoscale NMR detection of proton ($\mathrm{^{1}H}$) spins in immersion oil and fluorine ($\mathrm{^{19}F}$) spins in Fomblin, attaining a detection volume of $\mathrm{(3~nm)^3}$ and a sensitivity reaching the requirement for single-proton spin detection. This work establishes 4H-SiC quantum sensors as a compelling platform for nanoscale magnetic resonance, with promising applications in probing low-dimensional water phases, protein folding dynamics, and molecular interactions. - oai:arXiv.org:2512.10278v1 + Electric field diagnostics in a continuous rf plasma using Rydberg-EIT + https://arxiv.org/abs/2512.16867 + arXiv:2512.16867v1 Announce Type: new +Abstract: We present a non-invasive spectroscopic technique to measure electric fields in plasma, leveraging large polarizabilities and Stark shifts of Rydberg atoms. Rydberg Stark shifts are measured with high precision using narrow-linewidth lasers via Electromagnetically Induced Transparency (EIT) of rubidium vapor seeded into a continuous, inductively coupled radio-frequency (rf) plasma in a few mTorr of argon gas. Without plasma, the Rydberg-EIT spectra exhibit rf modulation sidebands caused by electric- and magnetic-dipole transitions in the rf drive coil. With the plasma present, the rf modulation sidebands vanish due to screening of the rf drive field from the plasma interior. The lineshapes of the EIT spectra in the plasma reflect the plasma's Holtsmark microfield distribution, allowing us to determine plasma density and collisional line broadening over a range of pressures and rf drive powers. The work is expected to have applications in non-invasive spatio-temporal electric-field diagnostics of low-pressure plasma, plasma sheaths, process plasma and dusty plasma. + oai:arXiv.org:2512.16867v1 + physics.atom-ph + physics.plasm-ph quant-ph - physics.bio-ph - Fri, 12 Dec 2025 00:00:00 -0500 - cross - http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Yu Chen, Qi Zhang, Yuanhong Teng, Chihang Luo, Zhijie Li, Jinpeng Liu, Ya Wang, Fazhan Shi, Jiangfeng Du + Fri, 19 Dec 2025 00:00:00 -0500 + new + http://creativecommons.org/licenses/by/4.0/ + Bineet Dash, Xinyan Xiang, Dingkun Feng, Eric Paradis, Georg Raithel - MorphZ: Enhancing evidence estimation through the Morph approximation - https://arxiv.org/abs/2512.10283 - arXiv:2512.10283v1 Announce Type: cross -Abstract: We introduce the Morph approximation, a class of product approximations of probability densities that selects low-order disjoint parameter blocks by maximizing the sum of their total correlations. We use the posterior approximation via Morph as the importance distribution in optimal bridge sampling. We denote this procedure by MorphZ, which serves as a post-processing estimator of the marginal likelihood. The MorphZ estimator requires only posterior samples together with the prior and likelihood, and is fully agnostic to the choice of sampler. We evaluate MorphZ's performance across statistical benchmarks, pulsar timing array (PTA) models, compact binary coalescence (CBC) gravitational-wave (GW) simulations and the GW150914 event. Across these applications, spanning low to high dimensionalities, MorphZ yields accurate evidence at substantially reduced computational cost relative to standard approaches, and can improve these estimates even when posterior coverage is incomplete. Its bridge sampling relative error diagnostic provides conservative uncertainty estimates. Because MorphZ operates directly on posterior draws, it complements exploration-oriented samplers by enabling fast and reliable evidence estimation, while it can be seamlessly integrated into existing inference workflows. - oai:arXiv.org:2512.10283v1 - astro-ph.IM - astro-ph.CO - physics.data-an - Fri, 12 Dec 2025 00:00:00 -0500 - cross + Multimer Embedding for Molecular Crystals Utilizing up to Tetramer Interactions + https://arxiv.org/abs/2512.16877 + arXiv:2512.16877v1 Announce Type: new +Abstract: Molecular crystals possess a highly complex crystallographic landscape which in many cases results in the experimental observation of multiple crystal structures for the same compound. Accurate results can often be obtained for such systems by employing periodic density functional theory using hybrid functionals; however, this is not always computationally feasible. One possibility to circumvent these expensive periodic calculations is the utilization of multimer embedding methods. Therein, the fully periodic crystal is described at a lower level of theory, and subsequently monomer energies, dimer interaction energies, etc. are corrected via high-level calculations. In this paper, we further extend such a multimer embedding approach by one multimer order for all investigated properties, allowing us to compute lattice energies up to the tetramer embedding level, and atomic forces, the stress tensor, and harmonic phonons up to the trimer level. We test the significance of including these higher-order multimers by embedding PBE0+MBD multimers into periodic PBE+MBD calculations utilizing the X23 benchmark set of molecular crystals and comparing the results to explicit periodic PBE0+MBD calculations. We show that tetramer interactions systematically improve the lattice energy approximation and explore multiple possibilities for multimer selection. Furthermore, we confirm that trimer interactions are crucial for the description of the stress tensor, yielding cell volumes within 1 % of those of PBE0+MBD. Subsequently, this also results in an improvement of the description of vibrational properties, giving on average gamma point frequencies within 1.3 wave numbers and vibrational free energies within 0.3 kJ/mol of the PBE0+MBD results. + oai:arXiv.org:2512.16877v1 + physics.chem-ph + cond-mat.mtrl-sci + Fri, 19 Dec 2025 00:00:00 -0500 + new http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - El Mehdi Zahraoui, Patricio Maturana-Russel, Avi Vajpeyi, Willem van Straten, Renate Meyer, Sergei Gulyaev + Alexander List, A. Daniel Boese, Johannes Hoja - A Kernel-based Resource-efficient Neural Surrogate for Multi-fidelity Prediction of Aerodynamic Field - https://arxiv.org/abs/2512.10287 - arXiv:2512.10287v1 Announce Type: cross -Abstract: Surrogate models provide fast alternatives to costly aerodynamic simulations and are extremely useful in design and optimization applications. This study proposes the use of a recent kernel-based neural surrogate, KHRONOS. In this work, we blend sparse high-fidelity (HF) data with low-fidelity (LF) information to predict aerodynamic fields under varying constraints in computational resources. Unlike traditional approaches, KHRONOS is built upon variational principles, interpolation theory, and tensor decomposition. These elements provide a mathematical basis for heavy pruning compared to dense neural networks. Using the AirfRANS dataset as a high-fidelity benchmark and NeuralFoil to generate low-fidelity counterparts, this work compares the performance of KHRONOS with three contemporary model architectures: a multilayer perceptron (MLP), a graph neural network (GNN), and a physics-informed neural network (PINN). We consider varying levels of high-fidelity data availability (0%, 10%, and 30%) and increasingly complex geometry parameterizations. These are used to predict the surface pressure coefficient distribution over the airfoil. Results indicate that, whilst all models eventually achieve comparable predictive accuracy, KHRONOS excels in resource-constrained conditions. In this domain, KHRONOS consistently requires orders of magnitude fewer trainable parameters and delivers much faster training and inference than contemporary dense neural networks at comparable accuracy. These findings highlight the potential of KHRONOS and similar architectures to balance accuracy and efficiency in multi-fidelity aerodynamic field prediction. - oai:arXiv.org:2512.10287v1 + Cartesian-nj: Extending e3nn to Irreducible Cartesian Tensor Product and Contracion + https://arxiv.org/abs/2512.16882 + arXiv:2512.16882v1 Announce Type: new +Abstract: Equivariant atomistic machine learning models have brought substantial gains in both extrapolation capability and predictive accuracy. Depending on the basis of the space, two distinct types of irreducible representations are utilized. From architectures built upon spherical tensors (STs) to more recent formulations employing irreducible Cartesian tensors (ICTs), STs have remained dominant owing to their compactness, elegance, and theoretical completeness. Nevertheless, questions have persisted regarding whether ST constructions are the only viable design principle, motivating continued development of Cartesian networks. In this work, we introduce the Cartesian-3j and Cartesian-nj symbol, which serve as direct analogues of the Wigner-3j and Wigner-nj symbol defined for tensor coupling. These coefficients enable the combination of any two ICTs into a new ICT. Building on this foundation, we extend e3nn to support irreducible Cartesian tensor product, and we release the resulting Python package as cartnn. Within this framework, we implement Cartesian counterparts of MACE, NequIP, and Allegro, allowing the first systematic comparison of Cartesian and spherical models to assess whether Cartesian formulations may offer advantages under specific conditions. Using TACE as a representative example, we further examine whether architectures constructed from irreducible Cartesian tensor product and contraction(ICTP and ICTC) are conceptually well-founded in Cartesian space and whether opportunities remain for improving their design. + oai:arXiv.org:2512.16882v1 + physics.chem-ph + cond-mat.mtrl-sci cs.LG - physics.flu-dyn - Fri, 12 Dec 2025 00:00:00 -0500 - cross + Fri, 19 Dec 2025 00:00:00 -0500 + new http://creativecommons.org/licenses/by-nc-sa/4.0/ - Apurba Sarker, Reza T. Batley, Darshan Sarojini, Sourav Saha + Zemin Xu, Chenyu Wu, Wenbo Xie, Daiqian Xie, P. Hu - Tunable discrete quasi-time crystal from a single drive - https://arxiv.org/abs/2512.10303 - arXiv:2512.10303v1 Announce Type: cross -Abstract: The search for exotic temporal orders in quantum matter, such as discrete quasi-time crystals (DQTCs), has become an important theme in nonequilibrium physics. However, realizing these phases has so far required complex protocols, such as drives with multiple incommensurate frequencies. Here, we present a significantly simpler mechanism: the emergence of DQTCs in a dissipative collective spin system subjected to only a single periodic drive. Remarkably, the characteristic frequencies of this novel phase are not fixed but can be continuously tuned by varying the strength of the drive. Even more strikingly, this tunability is punctuated by Arnold tongues, within which the response main frequency locks to rational fractions of the drive. Our model further provides a unified framework that also encompasses stationary, discrete time crystals and chaotic phases. This discovery simplifies the requirements for generating complex temporal orders and opens a viable route towards the experimental control and manipulation of quasi-time crystalline matter. - oai:arXiv.org:2512.10303v1 - quant-ph - cond-mat.quant-gas - physics.atom-ph - Fri, 12 Dec 2025 00:00:00 -0500 - cross - http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Xu Feng, Shuo Liu, Shu Chen, Shi-Xin Zhang + An evacuation simulator for pedestrian dynamics based on the Social Force Model + https://arxiv.org/abs/2512.16887 + arXiv:2512.16887v1 Announce Type: new +Abstract: The evacuation of pedestrians from enclosed spaces represents a key problem in safety engineering and infrastructure design. Analyzing the collective dynamics that emerge during evacuation processes requires simulation tools capable of capturing individual interactions and spatial constraints realistically. + In this work, we present \textit{SiCoBioNa}, an open-source evacuation simulator based on the Social Force Model (SFM). The software provides an intuitive graphical interface that allows users to configure pedestrian properties, spatial geometries, and initial conditions without requiring prior expertise in numerical modeling techniques. The SFM framework enables the representation of goal-oriented motion, interpersonal interactions, and interactions with fixed obstacles. + The simulator generates both quantitative data and visual outputs, facilitating the analysis of evacuation dynamics and the evaluation of different spatial configurations. Due to its modular and extensible design, \textit{SiCoBioNa} serves as a reproducible research tool for studies on pedestrian dynamics providing practical support for evacuation planning. + oai:arXiv.org:2512.16887v1 + physics.soc-ph + physics.comp-ph + Fri, 19 Dec 2025 00:00:00 -0500 + new + http://creativecommons.org/licenses/by/4.0/ + Juli\'an L\'opez, Virginia Mazzone, M. Leticia Rubio Puzzo, Juan Cruz Moreno - Tracking large chemical reaction networks and rare events by neural networks - https://arxiv.org/abs/2512.10309 - arXiv:2512.10309v1 Announce Type: cross -Abstract: Chemical reaction networks are widely used to model stochastic dynamics in chemical kinetics, systems biology and epidemiology. Solving the chemical master equation that governs these systems poses a significant challenge due to the large state space exponentially growing with system sizes. The development of autoregressive neural networks offers a flexible framework for this problem; however, its efficiency is limited especially for high-dimensional systems and in scenarios with rare events. Here, we push the frontier of neural-network approach by exploiting faster optimizations such as natural gradient descent and time-dependent variational principle, achieving a 5- to 22-fold speedup, and by leveraging enhanced-sampling strategies to capture rare events. We demonstrate reduced computational cost and higher accuracy over the previous neural-network method in challenging reaction networks, including the mitogen-activated protein kinase (MAPK) cascade network, the hitherto largest biological network handled by the previous approaches of solving the chemical master equation. We further apply the approach to spatially extended reaction-diffusion systems, the Schl\"ogl model with rare events, on two-dimensional lattices, beyond the recent tensor-network approach that handles one-dimensional lattices. The present approach thus enables efficient modeling of chemical reaction networks in general. - oai:arXiv.org:2512.10309v1 - q-bio.MN + KAN-Matrix: Visualizing Nonlinear Pairwise and Multivariate Contributions for Physical Insight + https://arxiv.org/abs/2512.15755 + arXiv:2512.15755v1 Announce Type: cross +Abstract: Interpreting complex datasets remains a major challenge for scientists, particularly due to high dimensionality and collinearity among variables. We introduce a novel application of Kolmogorov-Arnold Networks (KANs) to enhance interpretability and parsimony beyond what traditional correlation analyses offer. We present two interpretable, color-coded visualization tools: the Pairwise KAN Matrix (PKAN) and the Multivariate KAN Contribution Matrix (MKAN). PKAN characterizes nonlinear associations between pairs of variables, while MKAN serves as a nonlinear feature-ranking tool that quantifies the relative contributions of inputs in predicting a target variable. These tools support pre-processing (e.g., feature selection, redundancy analysis) and post-processing (e.g., model explanation, physical insights) in model development workflows. Through experimental comparisons, we demonstrate that PKAN and MKAN yield more robust and informative results than Pearson Correlation and Mutual Information. By capturing the strength and functional forms of relationships, these matrices facilitate the discovery of hidden physical patterns and promote domain-informed model development. + oai:arXiv.org:2512.15755v1 cs.LG - physics.bio-ph - Fri, 12 Dec 2025 00:00:00 -0500 + physics.app-ph + physics.data-an + Fri, 19 Dec 2025 00:00:00 -0500 cross http://creativecommons.org/licenses/by/4.0/ - Jiayu Weng, Xinyi Zhu, Jing Liu, Linyuan L\"u, Pan Zhang, Ying Tang + Luis A. De la Fuente, Hernan A. Moreno, Laura V. Alvarez, Hoshin V. Gupta - Optomagnonic generation of entangled travelling fields with different polarizations - https://arxiv.org/abs/2512.10338 - arXiv:2512.10338v1 Announce Type: cross -Abstract: The optomagnonic coupling between magnons and optical photons is an essential component for building remote quantum networks based on magnonics. Here we show that such a coupling, manifested as the magnon-induced Brillouin light scattering, can be exploited to entangle two propagating optical fields. The protocol employs two pairs of the whispering gallery modes coupled to the same magnon mode in a YIG sphere. In each pair a strong pump field is applied to activate either Stokes or anti-Stokes scattering. Due to the magnon mode involving in the two scattering processes and as a mediation, Stokes and anti-Stokes photons of different polarizations get entangled. The entanglement can be extracted by filtering the travelling output fields centered at the Stokes and anti-Stokes sidebands. Optimal conditions are identified under which strong output entanglement can be achieved. - oai:arXiv.org:2512.10338v1 - quant-ph - cond-mat.mes-hall - physics.app-ph - physics.optics - Fri, 12 Dec 2025 00:00:00 -0500 + Machine Learning Framework for Thrombosis Risk Prediction in Rotary Blood Pumps + https://arxiv.org/abs/2512.15761 + arXiv:2512.15761v1 Announce Type: cross +Abstract: Thrombosis in rotary blood pumps arises from complex flow conditions that remain difficult to translate into reliable and interpretable risk predictions using existing computational models. This limitation reflects an incomplete understanding of how specific flow features contribute to thrombus initiation and growth. This study introduces an interpretable machine learning framework for spatial thrombosis assessment based directly on computational fluid dynamics-derived flow features. A logistic regression (LR) model combined with a structured feature-selection pipeline is used to derive a compact and physically interpretable feature set, including nonlinear feature combinations. The framework is trained using spatial risk patterns from a validated, macro-scale thrombosis model for two representative scenarios. The model reproduces the labeled risk distributions and identifies distinct sets of flow features associated with increased thrombosis risk. When applied to a centrifugal pump, despite training on a single axial pump operating point, the model predicts plausible thrombosis-prone regions. These results show that interpretable machine learning can link local flow features to thrombosis risk while remaining computationally efficient and mechanistically transparent. The low computational cost enables rapid thrombogenicity screening without repeated or costly simulations. The proposed framework complements physics-based thrombosis modeling and provides a methodological basis for integrating interpretable machine learning into CFD-driven thrombosis analysis and device design workflows. + oai:arXiv.org:2512.15761v1 + cs.LG + physics.flu-dyn + Fri, 19 Dec 2025 00:00:00 -0500 cross - http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Zi-Xu Lu, Huai-Bing Zhu, Xuan Zuo, Jie Li + http://creativecommons.org/licenses/by/4.0/ + Christopher Blum, Michael Neidlin - Generation of mechanical cat-like states via optomagnomechanics - https://arxiv.org/abs/2512.10347 - arXiv:2512.10347v1 Announce Type: cross -Abstract: We propose an optomagnomechanical approach for preparing a cat-like superposition state of mechanical motion. Our protocol consists of two steps and is based on the magnomechanical system where the magnetostrictively induced displacement further couples to an optical cavity mode via radiation pressure. We first prepare a squeezed mechanical state by driving the magnomechanical system with a two-tone microwave field. We then switch off the microwave drives and send a weak red-detuned optical pulse to the optical cavity to weakly activate the optomechanical anti-Stokes scattering. We show that $k$ phonons can be subtracted from the prepared squeezed state, conditioned on the detection of $k$ anti-Stokes photons from the cavity output field, which prepares the mechanical motion in a cat-like state. The work provides a new avenue for preparing mechanical superposition states by combining opto- and magnomechanics and may find applications in the study of macroscopic quantum states and the test of collapse theories. - oai:arXiv.org:2512.10347v1 - quant-ph + Unveiling the amorphous ice layer during premelting using AFM integrating machine learning + https://arxiv.org/abs/2512.15772 + arXiv:2512.15772v1 Announce Type: cross +Abstract: Premelting plays a key role across physics, chemistry, materials and biology sciences but remains poorly understood at the atomic level due to surface characterization limitations. We report the discovery of a novel amorphous ice layer (AIL) preceding the quasi-liquid layer (QLL) during ice premelting, enabled by a machine learning framework integrating atomic force microscopy (AFM) with molecular dynamics simulations. This approach overcomes AFM's depth and signal limitations, allowing for three-dimensional surface structure reconstruction from AFM images. It further enables structural exploration of premelting interfaces across a wide temperature range that are experimentally inaccessible. We identify the AIL, present between 121-180K, displaying disordered two-dimensional hydrogen-bond network with solid-like dynamics. Our findings refine the ice premelting phase diagram and offering new insights into the surface growth dynamic, dissolution and interfacial chemical reactivity. Methodologically, this work establishes a novel framework for AFM-based 3D structural discovery, marking a significant leap in our ability to probe complex disordered interfaces with unprecedented precision and paving the way for future disciplinary research, including surface reconstruction, crystallization, ion solvation, and biomolecular recognition. + oai:arXiv.org:2512.15772v1 + cond-mat.mtrl-sci cond-mat.mes-hall - physics.optics - Fri, 12 Dec 2025 00:00:00 -0500 + physics.chem-ph + physics.comp-ph + Fri, 19 Dec 2025 00:00:00 -0500 cross - http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Hao-Tian Li, Hong-Bin Wang, Zi-Xu Lu, Jie Li + http://creativecommons.org/licenses/by/4.0/ + 10.1103/9fzf-y9n9 + Phys. Rev. X 15, 041048 (2025) + Binze Tang, Chon-Hei Lo, Tiancheng Liang, Jiani Hong, Mian Qin, Yizhi Song, Duanyun Cao, Ying Jiang, Limei Xu - The $k$-flip Ising game - https://arxiv.org/abs/2512.10389 - arXiv:2512.10389v1 Announce Type: cross -Abstract: A partially parallel dynamical noisy binary choice (Ising) game in discrete time of $N$ players on complete graphs with $k$ players having a possibility of changing their strategies at each time moment called $k$-flip Ising game is considered. Analytical calculation of the transition matrix of game as well as the first two moments of the distribution of $\varphi=N^+/N$, where $N^+$ is a number of players adhering to one of the two strategies, is presented. First two moments of the first hitting time distribution for sample trajectories corresponding to transition from a metastable and unstable states to a stable one are considered. A nontrivial dependence of these moments on $k$ for the decay of a metastable state is discussed. A presence of the minima at certain $k^*$ is attributed to a competition between $k$-dependent diffusion and restoring forces. - oai:arXiv.org:2512.10389v1 - cs.GT - cond-mat.stat-mech - physics.soc-ph - Fri, 12 Dec 2025 00:00:00 -0500 + Self-confinement of relativistic pair beams in magnetized interstellar plasmas: the case of pulsar X-ray filaments + https://arxiv.org/abs/2512.15847 + arXiv:2512.15847v1 Announce Type: cross +Abstract: The observation of filamentary X-ray structures near bow-shock pulsar wind nebulae (PWNe) -- such as the Guitar, Lighthouse, and PSR J2030$+$4415 nebulae -- and of slow-diffusion regions around pulsars like Geminga, Monogem, and PSR J0622$+$3749, challenges the standard picture of cosmic-ray transport in the interstellar medium, implying a diffusion coefficient two orders of magnitude smaller than the Galactic average. The suppressed diffusion can be attributed to self-generated magnetic turbulence, driven -- via the non-resonant streaming instability -- by electron--positron pairs escaping the PWNe. This instability requires a net current, yet the beam of escaping pairs is expected to be charge-neutral. We show that a charge-neutral pair beam propagating through an electron--proton plasma can spontaneously generate a net current. Using fully kinetic two- and three-dimensional particle-in-cell simulations with realistic mass ratio, we find that beam electrons get focused into self-generated magnetic filaments produced by the nonlinear evolution of the Weibel instability, while beam positrons remain unconfined. The resulting net (positron) current drives the non-resonant streaming instability, further amplifying the magnetic field. This mechanism provides a pathway for the onset of charge asymmetries in initially charge-neutral pair beams and for the growth of magnetic fluctuations that efficiently scatter the beam particles, with implications for the formation of X-ray filaments and, more broadly, for particle self-confinement in TeV halos around PWNe. + oai:arXiv.org:2512.15847v1 + astro-ph.HE + physics.plasm-ph + Fri, 19 Dec 2025 00:00:00 -0500 cross - http://creativecommons.org/licenses/by/4.0/ - Kovalenko Aleksandr, Andrey Leonidov + http://arxiv.org/licenses/nonexclusive-distrib/1.0/ + Luca Orusa, Lorenzo Sironi - Fitting magnetization data using continued fraction of straight lines - https://arxiv.org/abs/2512.10390 - arXiv:2512.10390v1 Announce Type: cross -Abstract: Magnetization of a ferromagnetic substance in response to an externally applied magnetic field increases with the strength of the field. This is because at the microscopic level, magnetic moments in certain regions or domains of the substance increasingly align with the applied field, while the amount of misaligned domains decreases. The alignment of such magnetic domains with an applied magnetic field forms the physical basis for the nonlinearity of magnetization. In this paper, the nonlinear function is approximated as a combination of continued fraction of straight lines. The resulting fit is used to interpret the nonlinear behavior in both growing and shrinking magnetic domains. The continued fraction of straight lines used here is an algebraic expression which can be used to estimate parameters using nonlinear regression. - oai:arXiv.org:2512.10390v1 + Introduction to Symbolic Regression in the Physical Sciences + https://arxiv.org/abs/2512.15920 + arXiv:2512.15920v1 Announce Type: cross +Abstract: Symbolic regression (SR) has emerged as a powerful method for uncovering interpretable mathematical relationships from data, offering a novel route to both scientific discovery and efficient empirical modelling. This article introduces the Special Issue on Symbolic Regression for the Physical Sciences, motivated by the Royal Society discussion meeting held in April 2025. The contributions collected here span applications from automated equation discovery and emergent-phenomena modelling to the construction of compact emulators for computationally expensive simulations. + The introductory review outlines the conceptual foundations of SR, contrasts it with conventional regression approaches, and surveys its main use cases in the physical sciences, including the derivation of effective theories, empirical functional forms and surrogate models. We summarise methodological considerations such as search-space design, operator selection, complexity control, feature selection, and integration with modern AI approaches. We also highlight ongoing challenges, including scalability, robustness to noise, overfitting and computational complexity. Finally we emphasise emerging directions, particularly the incorporation of symmetry constraints, asymptotic behaviour and other theoretical information. Taken together, the papers in this Special Issue illustrate the accelerating progress of SR and its growing relevance across the physical sciences. + oai:arXiv.org:2512.15920v1 cs.LG - cond-mat.mtrl-sci - physics.class-ph - Fri, 12 Dec 2025 00:00:00 -0500 + astro-ph.IM + cs.NE + physics.comp-ph + physics.data-an + Fri, 19 Dec 2025 00:00:00 -0500 cross http://creativecommons.org/licenses/by/4.0/ - Vijay Prakash S + Deaglan J. Bartlett, Harry Desmond, Pedro G. Ferreira, Gabriel Kronberger - Excitation energies and UV-Vis absorption spectra from INDO/s+ML - https://arxiv.org/abs/2512.10397 - arXiv:2512.10397v1 Announce Type: cross -Abstract: The semi-empirical INDO/s method is popular for studies of excitation energies and absorption of molecules due to its low computational requirement, making it possible to make predictions for large systems. However, its accuracy is generally low, particularly, when compared with the typical accuracy of other methods such as time-dependent density functional theory (TDDFT). Here, we present machine learning (ML) models that correct the INDO/s results with negligible increases in the amount of computing resources needed. While INDO/s excitations energies have an average error of about 1.1 eV relative to TDDFT energies, the added ML corrections reduce the error to 0.2 eV. Furthermore, this combination of INDO/s and ML produces UV-Vis absorption spectra that are in good agreement with the TDDFT predictions. - oai:arXiv.org:2512.10397v1 - cond-mat.mes-hall - physics.atm-clus - physics.chem-ph - physics.comp-ph + Magneto-optical Kerr effect in pump-probe setups + https://arxiv.org/abs/2512.16014 + arXiv:2512.16014v1 Announce Type: cross +Abstract: We develop a general theoretical framework for computing the time-resolved magneto-optical Kerr effect in ultrafast pump-probe setups, formulated within the Dynamical Projective Operatorial Approach (DPOA) and its application to the generalized linear-response theory for pumped systems. Furthermore, we exploit this formalism to express the post-pump optical conductivity and consequently the Kerr rotation in terms of the time-evolved single-particle density matrix (SPDM), providing a transparent and computationally efficient description of photo-excited multi-band systems. This extension, in addition to its lower computational cost, has the advantage of allowing the inclusion of phenomenological damping. We illustrate the formalism using both (i) a two-band tight-binding model, which captures the essential physics of ultrafast spin-charge dynamics and the Kerr rotation, and (ii) weakly spin-polarized germanium, as a realistic playground with a complex band structure. The results demonstrate that, by exploiting DPOA and/or its SPDM extension, one can reliably reproduce both the short-time features under the pump-pulse envelope and the long-time dynamics after excitation, offering a versatile framework for analyzing time-resolved magneto-optical Kerr effect experiments in complex materials. Moreover, this analysis clearly shows that the Kerr rotation can be used to deduce experimentally the relevant n-photon resonances for a given specific material. + oai:arXiv.org:2512.16014v1 + cond-mat.mtrl-sci + physics.optics quant-ph - Fri, 12 Dec 2025 00:00:00 -0500 + Fri, 19 Dec 2025 00:00:00 -0500 cross - http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Ezekiel Oyeniyi, Omololu Akin-Ojo + http://creativecommons.org/licenses/by/4.0/ + Amir Eskandari-asl (Dipartimento di Fisica 'E.R. Caianiello', Universit\`a degli Studi di Salerno, Fisciano), Adolfo Avella (Dipartimento di Fisica 'E.R. Caianiello', Universit\`a degli Studi di Salerno, Fisciano) - Electric-Field-Controlled Altermagnetic Transition for Neuromorphic Computing - https://arxiv.org/abs/2512.10405 - arXiv:2512.10405v1 Announce Type: cross -Abstract: Altermagnets represent a novel magnetic phase with transformative potential for ultrafast spintronics, yet efficient control of their magnetic states remains challenging. We demonstrate an ultra-low-power electric-field control of altermagnetism in MnTe through strain-mediated coupling in MnTe/PMN-PT heterostructures with negligible Joule heating. Application of +6 kV/cm electric fields induces piezoelectric strain in PMN-PT, modulating the N\'eel temperature from 310 to 328 K. As a result, around the magnetic phase transition, the altermagnetic spin splitting of MnTe is reversibly switched "on" and "off" by the electric fields. Meanwhile, the piezoelectric strain generates lattice distortions and magnetic structure changes in MnTe, enabling up to 9.7% resistance modulation around the magnetic phase transition temperature. Leveraging this effect, we implement programmable resistance states in a Hopfield neuromorphic network, achieving 100% pattern recognition accuracy at <=40% noise levels. This approach establishes the electric-field control as a low-power strategy for altermagnetic manipulation while demonstrating the viability of altermagnetic materials for energy-efficient neuromorphic computing beyond conventional charge-based architectures. - oai:arXiv.org:2512.10405v1 - cond-mat.mtrl-sci - cond-mat.mes-hall - physics.app-ph - Fri, 12 Dec 2025 00:00:00 -0500 - cross - http://creativecommons.org/publicdomain/zero/1.0/ - 10.1021/jacs.5c15276 - Zhiyuan Duan, Peixin Qin, Chengyan Zhong, Shaoxuan Zhang, Li Liu, Guojian Zhao, Xiaoning Wang, Hongyu Chen, Ziang Meng, Jingyu Li, Sixu Jiang, Xiaoyang Tan, Qiong Wu, Yu Liu, Zhiqi Liu - - - Stationary Couette-type flows in relativistic fluids - https://arxiv.org/abs/2512.10420 - arXiv:2512.10420v1 Announce Type: cross -Abstract: We investigate a class of stationary, planar-symmetric solutions of relativistic hydrodynamics, in which a dissipative fluid is confined between two parallel plates that move relative to each other and/or are maintained at different temperatures. We find that neglecting the heat flux leads to qualitatively incorrect flow profiles, even in systems with temperature-independent viscosity. This arises from the fact that, in special relativity, the heat flux itself contributes to the momentum density (the so-called "inertia of heat"). This effect is most evident in the Landau frame, where the fluid removes the excess energy generated by viscous heating by streaming across the boundaries. The analysis is further extended to the limit of vanishing chemical potential. - oai:arXiv.org:2512.10420v1 - nucl-th - hep-th + Direct calculation of steady-state hydrodynamic solar wind solutions with newtonian viscosity + https://arxiv.org/abs/2512.16028 + arXiv:2512.16028v1 Announce Type: cross +Abstract: Steady-state solutions to the Navier-Stokes equations are known to admit solutions that are singular at the sonic point. Consequently, inviscid solar wind models require special treatment of the solution near the sonic points, and this has proven to be a significant impediment to efficient modeling of the solar wind. In this paper we revisit the governing hydrodynamic equations for the expanding solar wind, with the inclusion of the classical (Newtonian) viscous stress , and we show how this inclusion eliminates the singularities that emerge from the inviscid equations. This result has been previously reported and used to generate solar wind profiles from initial conditions in the asymptotic limit; however, those studies did not include realistic treatments of the inner corona, and generally rejected the prospect of extrapolating solutions outward from the Sun into the heliosphere. Here, we expand this method to include external heating and optically thin radiative losses and show that solutions can be computed from initial conditions near the solar surface, thereby capturing the entire range of scales from below the transition region to the outer heliosphere in a single solution. Our approach is to cast the steady-state Navier-Stokes equations as a system of five coupled, ordinary differential equations (ODEs), which we solve using conventional methods, without any special treatment of the governing equations in the vicinity of the sonic point. The representative solutions that we present here demonstrate the utility and efficiency of this extrapolation method, which is considerably more realistic than commonly used analytical or empirical models. This method provides a direct approach to generating accurate solar wind profiles subject to observationally motivated initial conditions near the solar surface, at a fraction of the computational cost of comparable relaxation-based models. + oai:arXiv.org:2512.16028v1 + astro-ph.SR physics.flu-dyn - Fri, 12 Dec 2025 00:00:00 -0500 + physics.plasm-ph + physics.space-ph + Fri, 19 Dec 2025 00:00:00 -0500 cross http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Lorenzo Gavassino, Patrick Niekamp, S\"oren Schlichting, Gabriel S Denicol + 10.1051/0004-6361/202555327 + Roger B. Scott, Stephen J. Bradshaw, Mark G. Linton, Chris Lowder, Leonard Strachan - Engineering Multifunctional Response in Monolayer Fe3O4 via Zr Adsorption: From Half-Metallicity to Enhanced Piezoelectricity - https://arxiv.org/abs/2512.10434 - arXiv:2512.10434v1 Announce Type: cross -Abstract: Two-dimensional (2D) magnetic oxides are increasingly studied for their multifunctional potential in fields like spintronics, optoelectronics, and energy conversion. In this research, we conduct a detailed first-principles study of pure monolayer Fe3O4 and its modification through Zr adsorption at two sites: on top of an Fe atom and at the bridge between Fe atoms. Using spin-polarized density functional theory with the GGA plus U method, we examine how adsorption affects structure, electronic, magnetic, optical, elastic, and piezoelectric properties. The original monolayer shows half-metallicity, strong spin polarization, and a moderate in-plane piezoelectric effect. Zr adsorption causes local lattice distortions and orbital hybridization, resulting in intermediate electronic states, a reduced bandgap, and increased optical absorption in both spin channels. Notably, Zr at the bridge site greatly enhances dielectric response, optical conductivity, and piezoelectric coefficients, tripling e11 compared to the pristine layer. Elastic constants indicate mechanical softening after functionalization, and energy loss spectra display shifts in plasmon resonance. These findings suggest Zr adsorption offers a controllable, non-destructive way to tune spin, charge, and lattice interactions in Fe4O4 monolayers, connecting magnetic, optical, and piezoelectric functionalities within a single 2D material platform. - oai:arXiv.org:2512.10434v1 + Pulse-Mode Operation and Reliability of BEOL-Compatible Ferroelectric Non-Volatile Capacitive Memories with Amorphous Oxide Semiconductor Channels + https://arxiv.org/abs/2512.16040 + arXiv:2512.16040v1 Announce Type: cross +Abstract: Non-volatile capacitive memories (nvCAPs) exhibiting AC small-signal capacitance on/off ratio (Con/Coff) with non-destructive read have emerged as a promising device for next-generation memory paradigms. Recently, BEOL-compatible ferroelectric nvCAPs with an amorphous oxide semiconductor channel have been reported, suggesting the possibility of monolithic 3D integration of nvCAPs on top of CMOS. So far, the characterization studies on oxide-channel ferroelectric nvCAPs have been done using dual DC sweep C-V measurements which are typically performed over a time scale of a few seconds. However, non-volatile memory arrays typically require nvCAPs to operate under pulse-mode. It is thus crucial to advance understanding of the behavior of oxide-channel ferroelectric nvCAPs under pulse-mode operation, governed by the unique interplay between ferroelectric layer and oxide channel physics. In this study, we provide a systematic study of the pulse-mode operation of ferroelectric nvCAPs with an amorphous oxide semiconductor channel, including its pulse-based write characteristics and reliability characteristics. We examine overlap area, wake-up and pulse-width dependent Con and Coff writing characteristics under pulse-mode. Further, we suggest the importance of optimizing ferroelectric depolarization for Con retention, while reducing read-after-delay for Coff retention under pulse-mode. Lastly, non-destructive read operation for >10^9 read stress cycles at |Vread|=1V is demonstrated. + oai:arXiv.org:2512.16040v1 cond-mat.mtrl-sci - physics.comp-ph - Fri, 12 Dec 2025 00:00:00 -0500 + cond-mat.other + physics.app-ph + Fri, 19 Dec 2025 00:00:00 -0500 cross http://creativecommons.org/licenses/by/4.0/ - Sikander Azam, Qaiser Rafiq, Rajwali Khan, Hamdy Khamees Thabet + Junmo Lee, Chengyang Zhang, Tae-Hyeon Kim, Suman Datta, Shimeng Yu - Sensitivity threshold defines the optimal spin subset for ensemble quantum sensing - https://arxiv.org/abs/2512.10549 - arXiv:2512.10549v1 Announce Type: cross -Abstract: Finite drive power leaves unavoidable spatial gradients in control fields, preventing spin ensembles from reaching the standard-quantum-limit sensitivity. We derive an analytic expression of ensemble sensitivity for inhomogeneous spin sensors and introduce sensitivity thresholds that reveal the optimal spin subset. Applied to both pulsed and continuous-wave magnetometry, the optimal subsets deliver up to a tenfold improvement over conventional schemes relying on nominally uniform regions of the ensembles. We demonstrate phase-only digital holography to implement the optimal subsets and show that residual aberrations add less than 1 dB of sensitivity loss. Our framework imposes no fundamental trade-offs and extends quantum sensing to heterogeneous sensing environments. - oai:arXiv.org:2512.10549v1 - quant-ph - physics.app-ph - Fri, 12 Dec 2025 00:00:00 -0500 + Frequency Extraction from Invariant Flows + https://arxiv.org/abs/2512.16060 + arXiv:2512.16060v1 Announce Type: cross +Abstract: In non-degenerate integrable Hamiltonian systems, invariant tori can be parameterized equivalently by action variables or by their fundamental frequencies. We introduce an invariant-flow formulation for extracting fundamental frequencies of integrable Hamiltonian systems. By treating invariants as generators of commuting Hamiltonian flows, the frequencies are obtained from time-of-flight parameters along these flows, providing a direct alternative to action-angle constructions and spectral methods based on long time series. The approach yields an explicit numerical procedure that extends naturally to systems with multiple degrees of freedom. Its effectiveness is demonstrated using the McMillan map, where machine-precision accuracy is achieved. + oai:arXiv.org:2512.16060v1 + nlin.SI + physics.acc-ph + Fri, 19 Dec 2025 00:00:00 -0500 cross http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Suwan I. Kang, Minhyeok Kim, Sanghyo Park, Heonsik Lee, Keunyoung Lee, Donggyu Kim + Derong Xu, Yongjun Li, Yue Hao, Sergei Nagaitsev - Friction modifies the quasistatic mechanical response of a confined, poroelastic medium - https://arxiv.org/abs/2512.10553 - arXiv:2512.10553v1 Announce Type: cross -Abstract: The mechanical response of elastic porous media confined within rigid geometries is central to a wide range of industrial, geological, and biomedical systems. However, current models for these problems typically overlook the role of wall friction, and particularly its interaction with confinement. Here, we develop a theoretical framework to describe the interplay between the mechanics of the medium and Coulomb friction at the confining walls for slow, quasistatic deformations in response to two canonical uniaxial forcings: piston-driven loading and fluid-driven loading, followed by unloading. We find that, during compression, the stress field evolves according to a quasistatic advection-diffusion equation, extending classical poroelasticity results. The magnitude of friction is controlled by a single dimensionless number proportional to the friction coefficient and the aspect ratio of the confining geometry. During decompression, a portion of the solid matrix remains stuck due to friction, leading to hysteresis and to the propagation of a slip front. In piston-driven loading, the frictional stress is directly coupled to the solid effective stress, leading to exponential damping of the loading and striking changes to the displacement field. However, this coupling limits the energy dissipated by friction. In fluid-driven loading, the pressure gradient locally adds energy, decoupling the frictional stress from the effective stress. The displacement remains qualitatively unchanged but is quantitatively reduced due to large energy dissipation. In both cases, friction can have a substantial impact on the apparent mechanical properties of the medium. - oai:arXiv.org:2512.10553v1 - cond-mat.soft - physics.flu-dyn - Fri, 12 Dec 2025 00:00:00 -0500 + Complete Decomposition of Anomalous Diffusion in Variable Speed Generalized L\'evy Walks + https://arxiv.org/abs/2512.16073 + arXiv:2512.16073v1 Announce Type: cross +Abstract: Variable Speed Generalized L\'{e}vy Walks (VGLWs) are a class of spatio-temporally coupled stochastic processes that unify a broad range of previously studied models within a single parametrized framework. Their dynamics consist of discrete random steps, or flights, during which the walker's speed varies deterministically with both the elapsed time and the total duration of the flight. We investigate the anomalous diffusive behavior of VGLWs and analyze it through decomposition into the three fundamental constitutive effects that capture violations of the Central Limit Theorem (CLT): the Joseph effect, reflecting long-range increment correlations, the Noah effect, arising from heavy-tailed step-size distributions with infinite variance, and the Moses effect, associated with statistical aging and non-stationarity. Our results show that anomalous diffusion in VGLWs is typically generated by a nontrivial combination of all three effects, rather than being attributable to a single mechanism. Strikingly, we find that within the VGLW framework the Noah exponent $L$, which quantifies the strength of the Noah effect, is unbounded from above, revealing a richer and more extreme landscape of anomalous diffusion than in previously studied L\'{e}vy-walk-type models. + oai:arXiv.org:2512.16073v1 + cond-mat.stat-mech + physics.data-an + Fri, 19 Dec 2025 00:00:00 -0500 cross - http://creativecommons.org/licenses/by-nc-nd/4.0/ - T\'erence Desclaux, Callum Cuttle, Chris W. MacMinn, Olivier Liot + http://creativecommons.org/licenses/by-sa/4.0/ + Abhijit Bera, Kevin E. Bassler - An analytical framework for atmospheric tides on rocky planets. I. Formulation - https://arxiv.org/abs/2512.10578 - arXiv:2512.10578v1 Announce Type: cross -Abstract: Atmospheric thermal tides arise from the diurnal contrast in stellar irradiation. They exert a significant influence on the long-term rotational evolution of rocky planets because they can accelerate the planetary spin, thereby counteracting the decelerating effect of classical gravitational tides. Consequently, equilibrium tide-locked states may emerge, as exemplified by Venus and hypothesised for Precambrian Earth. Quantifying the atmospheric thermal torque and elucidating its dependence on tidal frequency -- both in the low- and high-frequency regimes -- is therefore essential. In particular, we focus here on the resonance that affected early Earth, which is associated with a forced Lamb wave. Within the framework of linear theory, we develop a new analytical model of the atmospheric response to both gravitational an thermal tidal forcings for two representative vertical temperature profiles that bracket the atmospheres of rocky planets: (i) an isothermal profile (uniform temperature) and (ii) an isentropic profile (uniform potential temperature). Dissipative processes are incorporated via Newtonian cooling. We demonstrate that the isothermal and isentropic cases are governed by the same general closed-form solution, and we derive explicit expressions for the three-dimensional tidal fields (pressure, temperature, density and wind velocities) throughout the spherical atmospheric shell. These results constitute the foundation for two forthcoming papers, in which analytical formulae for the thermotidal torque will be presented and compared with numerical solutions obtained from General Circulation Models (GCMs). - oai:arXiv.org:2512.10578v1 - astro-ph.EP - physics.ao-ph - physics.geo-ph - Fri, 12 Dec 2025 00:00:00 -0500 + ResDynUNet++: A nested U-Net with residual dynamic convolution blocks for dual-spectral CT + https://arxiv.org/abs/2512.16140 + arXiv:2512.16140v1 Announce Type: cross +Abstract: We propose a hybrid reconstruction framework for dual-spectral CT (DSCT) that integrates iterative methods with deep learning models. The reconstruction process consists of two complementary components: a knowledge-driven module and a data-driven module. In the knowledge-driven phase, we employ the oblique projection modification technique (OPMT) to reconstruct an intermediate solution of the basis material images from the projection data. We select OPMT for this role because of its fast convergence, which allows it to rapidly generate an intermediate solution that successfully achieves basis material decomposition. Subsequently, in the data-driven phase, we introduce a novel neural network, ResDynUNet++, to refine this intermediate solution. The ResDynUNet++ is built upon a UNet++ backbone by replacing standard convolutions with residual dynamic convolution blocks, which combine the adaptive, input-specific feature extraction of dynamic convolution with the stable training of residual connections. This architecture is designed to address challenges like channel imbalance and near-interface large artifacts in DSCT, producing clean and accurate final solutions. Extensive experiments on both synthetic phantoms and real clinical datasets validate the efficacy and superior performance of the proposed method. + oai:arXiv.org:2512.16140v1 + cs.CV + physics.med-ph + Fri, 19 Dec 2025 00:00:00 -0500 cross http://creativecommons.org/licenses/by/4.0/ - Pierre Auclair-Desrotour, Mohammad Farhat, Gwena\"el Bou\'e, Jacques Laskar + Ze Yuan, Wenbin Li, Shusen Zhao - All-photonic entanglement swapping with remote quantum dots - https://arxiv.org/abs/2512.10651 - arXiv:2512.10651v1 Announce Type: cross -Abstract: Entanglement swapping is a protocol that details how to create entanglement between previously uncorrelated particles. Its all-photonic version - mediated by the interference of photon pairs generated by separate quantum systems-finds disparate applications in quantum networks. So far, all-photonic entanglement swapping between remote systems has been implemented only using sources that operate probabilistically. However, the scaling up of quantum networks requires deterministic quantum emitters that do not suffer from a trade-off between degree of entanglement and photonpair generation rate. Here, we demonstrate all-photonic entanglement swapping using photon-pairs generated by two separate GaAs quantum dots. The emitters are deterministically embedded in hybrid semiconductor-piezoelectric devices that make the entangled-photons from two dissimilar quantum dots nearly identical. Entanglement swapping is demonstrated with a fidelity as high as 0.71(2), more than 10 standard deviations above the classical limit. The experimental data are quantitatively explained by a theoretical model that also suggests how to boost the protocol performances. Our work opens the path to the exploitation of quantum dot entangled-photon sources in quantum repeater networks. - oai:arXiv.org:2512.10651v1 - quant-ph - physics.optics - Fri, 12 Dec 2025 00:00:00 -0500 + Physics-Informed Neural Networks for Modeling the Martian Induced Magnetosphere + https://arxiv.org/abs/2512.16175 + arXiv:2512.16175v1 Announce Type: cross +Abstract: Understanding the magnetic field environment around Mars and its response to upstream solar wind conditions provide key insights into the processes driving atmospheric ion escape. To date, global models of Martian induced magnetosphere have been exclusively physics-based, relying on computationally intensive simulations. For the first time, we develop a data-driven model of the Martian induced magnetospheric magnetic field using Physics-Informed Neural Network (PINN) combined with MAVEN observations and physical laws. Trained under varying solar wind conditions, including B_IMF, P_SW, and {\theta}_cone, the data-driven model accurately reconstructs the three-dimensional magnetic field configuration and its variability in response to upstream solar wind drivers. Based on the PINN results, we identify key dependencies of magnetic field configuration on solar wind parameters, including the hemispheric asymmetries of the draped field line strength in the Mars-Solar-Electric coordinates. These findings demonstrate the capability of PINNs to reconstruct complex magnetic field structures in the Martian induced magnetosphere, thereby offering a promising tool for advancing studies of solar wind-Mars interactions. + oai:arXiv.org:2512.16175v1 + astro-ph.EP + cs.LG + physics.space-ph + Fri, 19 Dec 2025 00:00:00 -0500 cross - http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Mattia Beccaceci, Giuseppe Ronco, Fabrizio Cienzo, Pierpaolo Bassetti, Alessandro Laneve, Francesco Basso Basset, Tobias M. Krieger, Qurin Buchinger, Francesco Salusti, Barbara Souza Damasceno, Silke Kuhn, Saimon F. Covre da Silva, Sandra Stroj, Klaus D. J\"ons, Sven H\"ofling, Tobias Huber-Loyola, Armando Rastelli, Michele B. Rota, Rinaldo Trotta + http://creativecommons.org/licenses/by/4.0/ + Jiawei Gao, Chuanfei Dong, Chi Zhang, Yilan Qin, Simin Shekarpaz, Xinmin Li, Liang Wang, Hongyang Zhou, Abigail Tadlock - Scalable Optical Links for Controlling Bosonic Quantum Processors - https://arxiv.org/abs/2512.10706 - arXiv:2512.10706v1 Announce Type: cross -Abstract: Superconducting quantum computing has the potential to revolutionize computational capabilities. However, scaling up large quantum processors is limited by the cumbersome and heat-conductive electronic cables that connect room-temperature control electronics to quantum processors, leading to significant signal attenuation. Optical fibers provide a promising solution, but their use has been restricted to controlling simple two-level quantum systems over short distances. Here, we demonstrate optical control of a bosonic quantum processor, achieving universal operations on the joint Hilbert space of a transmon qubit and a storage cavity. Using an array of cryogenic fiber-integrated uni-traveling-carrier photodiodes, we prepare Fock states containing up to ten photons. Additionally, remote control of bosonic modes over a transmission distance of 15 km has been achieved, with fidelities exceeding 95%. The combination of high-dimensional quantum control, multi-channel operation, and long-distance transmission addresses the key requirements for scaling superconducting quantum computers and enables architectures for distributed quantum data centers. - oai:arXiv.org:2512.10706v1 + Near-Infrared Quantum Emission from Oxygen-Related Defects in hBN + https://arxiv.org/abs/2512.16197 + arXiv:2512.16197v1 Announce Type: cross +Abstract: Color centers hosted in hexagonal boron nitride (hBN) have emerged as a promising platform for single-photon emission and coherent spin-photon interfaces that underpin quantum communication and quantum networking technologies. As a wide-bandgap van der Waals material, hBN can host individual optically active quantum defects emitting across the ultraviolet to visible spectrum, but existing color centers often show broad phonon sidebands (PSBs), unstable emission, or inconvenient wavelengths. Here, we show a simple, scalable oxygen-plasma process that reproducibly creates oxygen-related single quantum emitters in hBN with blinking-free zero-phonon lines spanning the near-infrared (NIR) spectrum from 700-960 nanometers. These emitters demonstrate room-temperature operation, high brightness, and ultra-sharp cryogenic linewidths in the few-gigahertz range under non-resonant excitation. Analysis of the PSBs shows weak electron-phonon coupling and predominant zero-phonon-line emission, while first-principles calculations identify plausible oxygen-related defect configurations. These emitters provide a promising platform for indistinguishable NIR single photons towards free-space quantum networking. + oai:arXiv.org:2512.16197v1 quant-ph physics.optics - Fri, 12 Dec 2025 00:00:00 -0500 + Fri, 19 Dec 2025 00:00:00 -0500 cross http://creativecommons.org/licenses/by/4.0/ - Chuanlong Ma, Jia-Qi Wang, Linze Li, Jiajun Chen, Xiaoxuan Pan, Zheng-Hui Tian, Zheng-Xu Zhu, Jia-Hua Zou, Dingran Gu, Luyu Wang, Qiushi Chen, Weiting Wang, Xin-Biao Xu, Chang-Ling Zou, Baile Chen, Luyan Sun + Sean Doan, Sahil D. Patel, Yilin Chen, Jordan A. Gusdorff. Mark E. Turiansky, Luis Villagomez, Luka Jevremovic, Nicholas Lewis, Kenji Watanabe, Takashi Taniguchi, Lee C. Bassett, Chris Van de Walle, Galan Moody - Phase structure of the one-dimensional $\mathbb{Z}_2$ lattice gauge theory with second nearest-neighbor interactions - https://arxiv.org/abs/2512.10755 - arXiv:2512.10755v1 Announce Type: cross -Abstract: We investigate the ground-state phase diagram of a one-dimensional $\mathbb{Z}_2$ lattice gauge theory (LGT) model with hard-core bosons at half-filling, extending previous studies by including second nearest-neighbor (2NN) interactions. Using matrix product state techniques within the density matrix renormalization group, we compute charge gap, static structure factor, and pair-pair correlation functions for various interaction strengths and field parameters. We analyze two representative neatest-neighbor interaction strengths ($V_1$) that correspond to the Luttinger liquid (LL) and Mott insulator (MI) phases in the absence of the 2NN interactions. We introduce the 2NN coupling $V_2$ and investigate its impact on the system. Our results reveal very rich behavior. As the 2NN repulsion increases, in the case of small $V_1$, we observe a direct transition from the LL phase to a charge-ordered insulator (COI) phase, whereas for large $V_1$, we observe a transition from the MI phase (previously found with only $V_1$ included), going through an intermediate LL region, and finally reaching the COI regime. Additionally, the inclusion of 2NN interactions enhances charge order and suppresses pair coherence, evidenced by sharp peaks in the structure factor and rapid decay in pair-pair correlators. Our work extends the well-studied phase structure of 1D $\mathbb{Z}_2$ LGT models and demonstrates the interplay between gauge fields, confinement, and extended interactions. - oai:arXiv.org:2512.10755v1 - cond-mat.str-el - hep-lat - hep-ph + Beyond dpa: an atomistic framework for a quantitative description of radiation damage in YBa2Cu3O7 + https://arxiv.org/abs/2512.16249 + arXiv:2512.16249v1 Announce Type: cross +Abstract: Radiation damage in high-temperature cuprate superconductors represents one of the main technological challenges for their deployment in harsh environments, such as fusion reactors and accelerator facilities. Their complex crystal structure makes modeling irradiation effects in this class of materials a particularly demanding task, for which existing damage models remain inadequate. In this work, we develop an atomistic-based approach for describing primary radiation damage in YBa2Cu3O7, by coupling Molecular Dynamics and Binary Collision Approximation simulations in a way that makes them complementary. When integrated with Primary Knock-on Atom spectra obtained from Monte Carlo codes, our results establish a framework for multiscale modeling of radiation damage, enabling quantitative estimates of several damage descriptors, such as defect production, defect clustering, and the effective damaged volume for any specific irradiation conditions where collision cascades dominate. This computational approach is suitable for the prediction of irradiation effects in any complex functional oxide, with applications ranging from aerospace to nuclear fusion and high-energy physics. + oai:arXiv.org:2512.16249v1 + cond-mat.supr-con + cond-mat.mtrl-sci physics.comp-ph - quant-ph - Fri, 12 Dec 2025 00:00:00 -0500 - cross - http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Yeimer Zambrano, Aleksey Alekseev, Konrad J. Kapcia, Krzysztof Cichy, Agnieszka Cichy - - - Modeling Light Signals Using Data from the First Pulsed Neutron Source Program at the DUNE Vertical Drift ColdBox Test Facility at CERN Neutrino Platform - https://arxiv.org/abs/2512.10790 - arXiv:2512.10790v1 Announce Type: cross -Abstract: In this paper, we present a first quantitative test of detected light signals produced in a pulsed neutron source run in a small vertical drift LArTPC at the CERN neutrino platform ColdBox test facility. The ColdBox cryostat, detectors, neutron sources, and particle interactions are modeled and simulated using Fluka. A good agreement is found in the detected number of photoelectrons, with values below 650 photoelectrons in both data and simulation, for all four X-ARAPUCA photodetectors on the cathode in the LArTPC. A time constant is also fitted from the neutron-beam-off light signal spectrum and found consistent between data and MC. Several important systematic effects are discussed and serve as guides for future runs at larger LArTPCs. - oai:arXiv.org:2512.10790v1 - hep-ex - physics.ins-det - Fri, 12 Dec 2025 00:00:00 -0500 - cross - http://creativecommons.org/licenses/by-nc-nd/4.0/ - A. Paudel, W. Shi, P. Sala, F. Cavanna, W. Johnson, J. Wang, W. Ketchum, F. Resnati, A. Heindel, A. Ashkenazi, E. Bertholet, E. Bertolini, D. A. Martinez Caicedo, E. Calvo, A. Canto, S. Manthey Corchado, C. Cuesta, Z. Djurcic, M. Fani, A. Feld, S. Fogarty, F. Galizzi, S. Gollapinni, Y. Kerma\"idic, A. Kish, F. Marinho, D. Torres Mu\~noz, A. Verdugo de Osa, L. Paulucci, W. Pellico, V. Popov, J. Rodriguez Rondon, D. Leon Silverio, S. Sacerdoti, H. Souza, R. C Svoboda, D. Totani, V. Trabattoni, L. Zambelli - - - Identifiable factor analysis for mixed continuous and binary variables based on the Gaussian-Grassmann distribution - https://arxiv.org/abs/2512.10804 - arXiv:2512.10804v1 Announce Type: cross -Abstract: We develop a factor analysis for mixed continuous and binary observed variables. To this end, we utilized a recently developed multivariate probability distribution for mixed-type random variables, the Gaussian-Grassmann distribution. In the proposed factor analysis, marginalization over latent variables can be performed analytically, yielding an analytical expression for the distribution of the observed variables. This analytical tractability allows model parameters to be estimated using standard gradient-based optimization techniques. We also address improper solutions associated with maximum likelihood factor analysis. We propose a prescription to avoid improper solutions by imposing a constraint that row vectors of the factor loading matrix have the same norm for all features. Then, we prove that the proposed factor analysis is identifiable under the norm constraint. We demonstrate the validity of this norm constraint prescription and numerically verified the model's identifiability using both real and synthetic datasets. We also compare the proposed model with quantification method and found that the proposed model achieves better reproducibility of correlations than the quantification method. - oai:arXiv.org:2512.10804v1 - stat.ME - physics.data-an - Fri, 12 Dec 2025 00:00:00 -0500 - cross - http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Takashi Arai - - - Estimating Detector Error Models on Google's Willow - https://arxiv.org/abs/2512.10814 - arXiv:2512.10814v1 Announce Type: cross -Abstract: We consolidate recent theoretical advances in Detector Error Model (DEM) estimation and formalize several algorithms to learn DEM parameters and structure from syndromes without using a decoder, demonstrating recovery of known DEMs from simulated syndromes with precision limited only by finite-sample effects. We then apply these algorithms to estimate DEMs from Google's 72- and 105-qubit chips. Using a likelihood function that is tractable for small DEMs, we show that DEMs estimated directly from syndromes agree more closely with unseen syndromes than DEMs trained to optimize logical performance, whereas the latter outperform the former as priors for decoders in logical memory experiments. We used a time-series of estimated DEMs to track both global error and specific local errors over the course of a QEC experiment, suggesting applications in online characterization. We employ a sequence of DEM estimation techniques to discover and quantify long-range detector correlations spanning the width of the 105-qubit chip, for which DEM analysis suggests correlated measurement errors rather than high-weight Pauli errors as the most likely explanation. Finally, we present two artifacts in repetition code syndromes that are \emph{not} well-modeled by a DEM: correlated flipping of pairs of adjacent detectors in many consecutive rounds of QEC, and signatures consistent with radiation events occurring more frequently than previously reported. - oai:arXiv.org:2512.10814v1 - quant-ph - physics.data-an - Fri, 12 Dec 2025 00:00:00 -0500 + Fri, 19 Dec 2025 00:00:00 -0500 cross http://creativecommons.org/licenses/by-nc-nd/4.0/ - Kregg Elliot Arms, Martin James McHugh, Joseph Edward Nyhan, William Frederick Reus, James Loudon Ulrich - - - Topological Engineering of a Frustrated Antiferromagnetic Triradical in Aza-Triangulene Architectures - https://arxiv.org/abs/2512.10869 - arXiv:2512.10869v1 Announce Type: cross -Abstract: Open-shell nanographenes provide a versatile platform to host unconventional magnetic states within their {\pi}-conjugated networks. Particularly appealing are graphene architectures that incorporate spatially separated radicals and tunable interactions, offering a scalable route toward spin-based quantum architectures. Triangulenes are ideal for this purpose, as their radical count scales with size, although strong hybridization prevents individual spin control. Here, we realize a radical reconfiguration strategy that transforms a single-radical aza-triangulene into a frustrated antiferromagnetic triradical by covalently extending it with armchair anthene moieties of increasing length. Scanning tunnelling spectroscopy reveals edge-localized Kondo resonances and a doublet-to-quartet spin excitation, evidencing the emergence of correlated spins. Multi-reference electronic-structure calculations trace the progressive increase in polyradical character with anthene length, driven by the clustering of frontier states within a narrow energy window. Consequently, the initial single-radical doublet reorganizes into a frustrated triradical with weakly coupled edge spins, a molecular analog of a three-qubit quantum register. - oai:arXiv.org:2512.10869v1 - cond-mat.mes-hall - physics.chem-ph - Fri, 12 Dec 2025 00:00:00 -0500 - cross - http://creativecommons.org/licenses/by-nc-sa/4.0/ - Francisco Romero-Lara, Manuel Vilas-Varela, Ricardo Ortiz, Manish Kumar, Alessio Vegliante, Luc\'ia G\'omez-Rodrigo, Jan Patrick Calupitan, Diego Soler, Nikas Friedrich, Dongfei Wang, Jon Ortuzar, Stefano Trivini, Fabian Schulz, Thomas Frederiksen, Pavel Jel\'inek, Diego Pe\~na, Jose Ignacio Pascual + Federico Ledda, Daniele Torsello, Davide Gambino, Flyura Djurabekova, Fabio Calzavara, Niccol\`o Di Eugenio, Ville Jantunen, Antonio Trotta, Erik Gallo, Kai Nordlund, Francesco Laviano - Impact of geometry on 1D molecular-kinetics simulations of acoustic-gravity wave propagation into the exosphere - https://arxiv.org/abs/2512.10887 - arXiv:2512.10887v1 Announce Type: cross -Abstract: Direct Simulation Monte Carlo (DSMC) calculations of acoustic gravity wave propagation into the exobase region of a Mars-like atmosphere reveal that radial geometry can reduce wave-driven heating compared to a Cartesian model. We examine two acoustic wave (AW) modes with periods of 11 minutes (AW1) and 5.5 minutes (AW2) propagating from 100 to 320 km altitude using a radial molecular kinetics model. The wave-driven heating was reduced by 40-56% with cycle-averaged temperature gradient $\langle dT/dr \rangle$ decreasing from 9.4 K per scale height H0 to 5.6 K/H$_0$ for AW1 and from 4.4 K/H$_0$ to 1.9 K/H$_0$ for AW2 when accounting for planetary curvature. While the growth in wave density amplitude was attenuated for the 1D radial geometry as well, the heating differences are more pronounced, with both effects driven by geometric spreading accumulating as waves propagate into increasingly rarefied regions. These findings suggest that accounting for curvature effects is crucial when conducting DSMC estimates of acoustic wave contributions to thermospheric heating and atmospheric escape, as Cartesian-based derived counterparts may be overestimated by factors of 1.7-2.3 for these frequencies. - oai:arXiv.org:2512.10887v1 - astro-ph.EP - physics.ao-ph - Fri, 12 Dec 2025 00:00:00 -0500 + An Open Workflow Model for Improving Educational Video Design: Tools, Data, and Insights + https://arxiv.org/abs/2512.16254 + arXiv:2512.16254v1 Announce Type: cross +Abstract: Educational videos are widely used across various instructional models in higher education to support flexible and self-paced learning. However, student engagement with these videos varies significantly depending on how they are designed. While several studies have identified potential influencing factors, there remains a lack of scalable tools and open datasets to support large-scale, data-driven improvements in video design. This study aims to advance data-driven approaches to educational video design. Its core contributions include: (1) a workflow model for analysing educational videos; (2) an open-source implementation for extracting video metadata and features; (3) an accessible, community-driven database of video attributes; (4) a case study applying the approach to two engineering courses; and (5) an initial machine learning-based analysis to explore the relative influence of various video characteristics on student engagement. This work lays the groundwork for a shared, evidence-based approach to educational video design. + oai:arXiv.org:2512.16254v1 + stat.AP + physics.ed-ph + Fri, 19 Dec 2025 00:00:00 -0500 cross http://creativecommons.org/licenses/by-nc-nd/4.0/ - 10.1016/j.icarus.2025.116900 - Icarus, 447 (2026), 116900 - Jose A. Perez Chavez, Orenthal J. Tucker, Shane R. Carberry Mogan, Robert E. Johnson, Christopher Blaszczak-Boxe + Mohamed Tolba, Olivia Kendall, Daniel Tudball Smith, Alexander Gregg, Tony Vo, Scott Wordley - Quantifying classical and quantum bounds for resolving closely spaced, non-interacting, simultaneously emitting dipole sources in optical microscopy - https://arxiv.org/abs/2512.10889 - arXiv:2512.10889v1 Announce Type: cross -Abstract: Recent theoretical and experimental work has shown that the quantum Fisher information associated with estimating the separation between two optical point sources remains finite at small separations, effectively opening new routes to super-resolution imaging of simultaneously emitting sources. Most studies to date, however, implicitly invoke the scalar approximation, which is not appropriate in the context of high-numerical-aperture microscopy. Utilizing parameter estimation theory, here we consider the estimation of separation between two closely spaced dipole emitters, a commonly employed model for single-molecule optical beacons. We consider two limiting cases: one in which the orientations of the emitters are fixed and equal, and another in which both dipoles freely sample all of orientation space over the course of the measurement. We quantify precision limits using quantum and classical variants of the Fisher information and Cram\'{e}r-Rao bound. In all cases, the vectorial nature of the emission complicates the analyses, but with appropriate filtering of the collected light in the azimuthal-radial polarization basis, a previously proposed scheme to saturate the quantum Fisher information via image inversion interferometry can be salvaged. - oai:arXiv.org:2512.10889v1 - quant-ph + Pixel Super-Resolved Fluorescence Lifetime Imaging Using Deep Learning + https://arxiv.org/abs/2512.16266 + arXiv:2512.16266v1 Announce Type: cross +Abstract: Fluorescence lifetime imaging microscopy (FLIM) is a powerful quantitative technique that provides metabolic and molecular contrast, offering strong translational potential for label-free, real-time diagnostics. However, its clinical adoption remains limited by long pixel dwell times and low signal-to-noise ratio (SNR), which impose a stricter resolution-speed trade-off than conventional optical imaging approaches. Here, we introduce FLIM_PSR_k, a deep learning-based multi-channel pixel super-resolution (PSR) framework that reconstructs high-resolution FLIM images from data acquired with up to a 5-fold increased pixel size. The model is trained using the conditional generative adversarial network (cGAN) framework, which, compared to diffusion model-based alternatives, delivers a more robust PSR reconstruction with substantially shorter inference times, a crucial advantage for practical deployment. FLIM_PSR_k not only enables faster image acquisition but can also alleviate SNR limitations in autofluorescence-based FLIM. Blind testing on held-out patient-derived tumor tissue samples demonstrates that FLIM_PSR_k reliably achieves a super-resolution factor of k = 5, resulting in a 25-fold increase in the space-bandwidth product of the output images and revealing fine architectural features lost in lower-resolution inputs, with statistically significant improvements across various image quality metrics. By increasing FLIM's effective spatial resolution, FLIM_PSR_k advances lifetime imaging toward faster, higher-resolution, and hardware-flexible implementations compatible with low-numerical-aperture and miniaturized platforms, better positioning FLIM for translational applications. + oai:arXiv.org:2512.16266v1 + cs.CV + cs.LG + physics.med-ph physics.optics - Fri, 12 Dec 2025 00:00:00 -0500 + Fri, 19 Dec 2025 00:00:00 -0500 cross http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Armine I. Dingilian, Aarnah Kurella, Cheyenne S. Mitchell, Dhananjay Dhruva, David J. Durden, Mikael P. Backlund + Paloma Casteleiro Costa, Parnian Ghapandar Kashani, Xuhui Liu, Alexander Chen, Ary Portes, Julien Bec, Laura Marcu, Aydogan Ozcan - A telecommunications system based on axion dark matter coherent transmission - https://arxiv.org/abs/2005.07000 - arXiv:2005.07000v3 Announce Type: replace -Abstract: In this manuscript we anticipate axion detection in order to theorize on a novel telecommunications system based on the coherent axion-two-photon vertex Primakoff effect conversion and reversion of microwave photons transmitting a modulated signal. We suggest a possible set-up for an experiment or industrial application using state-of-the-art technology and we estimate the output power and photon rate expected to be received as a function of the axion-photon coupling constant $g_{a\gamma\gamma}$. We find that, although challenging,this system has no physical restriction to render it unfeasible. Finally, we summarize the advantages and disadvantages of a hypothetical axion-based telecommunications system compared to traditional telecommunication systems. We then extend the discussion, noting the more important conclusions. - oai:arXiv.org:2005.07000v3 - physics.ins-det - hep-ex - Fri, 12 Dec 2025 00:00:00 -0500 - replace + Explosive dispersal of non-motile microbes through metabolic buoyancy + https://arxiv.org/abs/2512.16288 + arXiv:2512.16288v1 Announce Type: cross +Abstract: For non-motile microorganisms, spatial expansion in quiescent fluids is presumed to be limited by diffusion. We report that microbial colonies can explosively circumvent this constraint through a self-amplifying physical process. As non-motile yeast and bacteria metabolize dense nutrients into lighter waste within their fluid environment, they generate buoyancy-driven Rayleigh-B\'enard convection, an ubiquitous fluid-dynamical phenomenon that organizes material on scales from chemical reactors to planetary atmospheres. This robust, self-generated flow fragments and disperses cellular aggregates, which seed new growth sites, enhancing total metabolic activity and further strengthening the convective flow in an autocatalytic cycle. The resulting expansion follows accelerating power-law kinetics, quantitatively captured by a physical theory linking metabolic flux to flow velocity, and produces fractal patterns through a flow-focusing instability we term Circulation-Driven Aggregation, the hydrodynamic analogue of Diffusion-Limited Aggregation. This `metabolic fireworks' mechanism establishes a canonical instance of proliferating active matter, where cellular metabolic activity self-organizes a physical transport engine--a living Rayleigh-B\'enard convection--providing a fundamental, physics-based dispersal strategy. + oai:arXiv.org:2512.16288v1 + cond-mat.soft + nlin.AO + nlin.PS + physics.bio-ph + physics.flu-dyn + Fri, 19 Dec 2025 00:00:00 -0500 + cross http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Javier De Miguel-Hern\'andez + Jimreeves David, Shashi Thutupalli - Demonstration and frequency noise characterization of a 17 $\mu$m quantum cascade laser - https://arxiv.org/abs/2310.16460 - arXiv:2310.16460v3 Announce Type: replace -Abstract: We evaluate the spectral performance of a novel continuous-wave room-temperature distributed feedback quantum cascade laser operating at the long wavelength of 17 $\mu$m. By demonstrating broadband laser absorption spectroscopy of the $\nu$2 fundamental vibrational mode of N2O molecules, we have determined the spectral range and established the spectroscopic potential of this laser. We have characterized the frequency noise and measured the line width of this new device, uncovering a discrepancy with the current consensus on the theoretical modeling of quantum cascade lasers. Our results confirm the potential of such novel narrow-line-width sources for vibrational spectroscopy. Extending laser spectroscopy to longer wavelength is a fascinating prospect that paves the way for a wide range of opportunities from chemical detection, to frequency metrology as well as for exploring light-matter interaction with an extended variety of molecules, from ultra-cold diatomic species to increasingly complex molecular systems. - oai:arXiv.org:2310.16460v3 + Feedback Cooling and Thermometry of a Single Trapped Ion Using a Knife Edge + https://arxiv.org/abs/2512.16368 + arXiv:2512.16368v1 Announce Type: cross +Abstract: We report on the first feedback cooling of a single trapped ion below the Doppler limit of $\hbar\Gamma/2 k_\mathrm{B}$. The motion of a single ion is monitored in real-time and cooled up to 9-times below the Doppler cooling temperature by applying electronic feedback. Real-time motion detection is implemented by imaging the fluorescence photons emitted by the ion onto a knife edge and detecting the transmitted light, a method used so far to cool trapped nanoparticles. The intensity modulation of the fluorescence resulting from the ion motion is used to generate and apply the feedback signal and also to determine the ion temperature. The method benefits from a high rate of detected scattered photons, which can be a challenge, and which we address by using a parabolic mirror for collecting the fluorescence. + oai:arXiv.org:2512.16368v1 + quant-ph physics.atom-ph - physics.ins-det physics.optics - Fri, 12 Dec 2025 00:00:00 -0500 - replace - http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Laser and Photonics Reviews, 2025, pp.e00879 - M Manceau (LPL), T E Wall (CCM), H Philip (IES), A N Baranov (IES), Olivier Lopez (LPL), M R Tarbutt (CCM), R Teissier (IES), B Darqui\'e (LPL) - - - A Universal Relation Between Intermittency and Dissipation in Turbulence - https://arxiv.org/abs/2407.15953 - arXiv:2407.15953v3 Announce Type: replace -Abstract: Fundamental quantities of turbulent flows, such as the dissipation constant $C_\varepsilon$ and the intermittency factor $\mu$, are examined in relation to each other for a broader class of non-ideal turbulent flows. In the context of the energy cascade, it is known that $C_\varepsilon$ reflects its basic overall properties, while $\mu$ quantifies the intermittency that emerges throughout the cascade. Using an extensive hot-wire dataset of turbulent wakes, grid-generated turbulence, and an axisymmetric jet, we individually analyze these quantities as one-dimensional surrogates of the energy cascade, considering only data that exhibit consistent scaling behavior. We find that $\mu$ is inversely proportional to $C_\varepsilon$, offering a new empirical principle that bridges the gap between large and small scales in arbitrary turbulent flows. - oai:arXiv.org:2407.15953v3 - physics.flu-dyn - Fri, 12 Dec 2025 00:00:00 -0500 - replace - http://creativecommons.org/licenses/by/4.0/ - F. Schmitt, A. Fuchs, J. Peinke, M. Obligado - - - ERF: Energy Research and Forecasting Model - https://arxiv.org/abs/2412.04395 - arXiv:2412.04395v2 Announce Type: replace -Abstract: High performance computing (HPC) architectures have undergone rapid development in recent years. As a result, established software suites face an ever increasing challenge to remain performant on and portable across modern systems. Many of the widely adopted atmospheric modeling codes cannot fully (or in some cases, at all) leverage the acceleration provided by General-Purpose Graphics Processing Units (GPGPUs), leaving users of those codes constrained to increasingly limited HPC resources. Energy Research and Forecasting (ERF) is a regional atmospheric modeling code that leverages the latest HPC architectures, whether composed of only Central Processing Units (CPUs) or incorporating GPUs. ERF contains many of the standard discretizations and basic features needed to model general atmospheric dynamics as well as flows relevant to renewable energy. The modular design of ERF provides a flexible platform for exploring different physics parameterizations and numerical strategies. ERF is built on a state-of-the-art, well-supported, software framework (AMReX) that provides a performance portable interface and ensures ERF's long-term sustainability on next generation computing systems. This paper details the numerical methodology of ERF and presents results for a series of verification and validation cases. - oai:arXiv.org:2412.04395v2 - physics.ao-ph - physics.flu-dyn - Fri, 12 Dec 2025 00:00:00 -0500 - replace + Fri, 19 Dec 2025 00:00:00 -0500 + cross http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - 10.1029/2024MS004884 - Lattanzi, A., Almgren, A., Quon, E., Natarajan, M., Kosovic, B., Mirocha, J., et al. (2025). ERF: Energy research and forecasting model. Journal of Advances in Modeling Earth Systems, 17, e2024MS004884 - Aaron Lattanzi, Ann Almgren, Eliot Quon, Mahesh Natarajan, Branko Kosovic, Jeff Mirocha, Bruce Perry, David Wiersema, Donald Willcox, Xingqiu Yuan, Weiqun Zhang + Hans Dang, Sebastian Luff, Martin Fischer, Markus Sondermann, Gerd Leuchs - Partially Coherent X-Ray Oscilex Radiation from a FEL-Modulated Positron Bunch during Its Planar Channeling in a Crystalline Undulator - https://arxiv.org/abs/2412.10205 - arXiv:2412.10205v3 Announce Type: replace -Abstract: The radiation emitted at zero angle by a microbunched positron bunch undergoing planar channeling in a crystalline undulator (CU) is studied. The bunch energy is assumed to be far above the threshold for radiation generation in the dispersive CU medium. Besides the usual ``hard'' undulator radiation produced by channeling oscillations (channeling undulator radiation) and by the CU bending (crystalline undulator radiation), a ``soft'' medium-polarization component also appears at zero angle due to the oscillations that excite atomic electrons. We refer to this soft component as Oscilex (oscillationally-excited) radiation. Since the two types of oscillations have different frequencies, they yield two distinct frequency components of both undulator and Oscilex radiation. The Oscilex frequencies are set by the plasma frequency and the characteristic oscillation frequency and are, to high accuracy, independent of the positron energy. The CU period is chosen so that the radiation wavelength is not shorter than the microbunch length, ensuring coherent emission from microbunches and partially coherent Oscilex emission from the full bunch. Analytical expressions are obtained for the spectral line shapes and the number of photons of spontaneous Oscilex radiation. For partially coherent emission, Gaussian distributions are used for both the bunch and microbunches. Gain factors for the two Oscilex components, including longitudinal form-factors, and the total number of partially coherent photons are derived. A positron bunch with LCLS parameters, modulated by SASE XFEL, channeling between (1 1 0) planes of a periodically bent diamond crystal is analyzed. The number of spontaneously emitted Oscilex photons exceeds the number of positrons by $1\text{{\div}}2$ orders of magnitude, and the gain factors reach $10^3 \text{{\div}} 10^4$. - oai:arXiv.org:2412.10205v3 - physics.acc-ph - hep-ex - hep-ph - physics.class-ph + Instantaneous velocity during quantum tunnelling + https://arxiv.org/abs/2512.16385 + arXiv:2512.16385v1 Announce Type: cross +Abstract: Quantum tunnelling, a hallmark phenomenon of quantum mechanics, allows particles to pass through the classically forbidden region. It underpins fundamental processes ranging from nuclear fusion and photosynthesis to the operation of superconducting qubits. Yet the underlying dynamics of particle motion during tunnelling remain subtle and are still the subject of active debate. Here, by analyzing the temporal evolution of the tunnelling process, we show that the particle velocity inside the barrier continuously relaxes from a large initial value toward a smaller one, and may even approach zero in the evanescent regime. Meanwhile, the probability density within the barrier gradually builds up before reaching its stationary profile, in contrast to existing inherently. In addition, starting from the steady-state equations, we derive an explicit relation between the particle velocity and the barrier width, and show that the velocity in evanescent states approaches zero when the barrier is sufficiently wide. These findings resolve the apparent paradox of a vanishing steady-state velocity coexisting with a finite particle density. We point out that defining an effective speed from the probability density, rather than from the probability current, can lead to spuriously nonzero "stationary speed," as appears to be the case in Ref. [Nature 643, 67 (2025)]. Our work establishes a clear dynamical picture for the formation of tunnelling flow and provides a theoretical foundation for testing time-resolved tunnelling phenomena. + oai:arXiv.org:2512.16385v1 + quant-ph physics.optics - Fri, 12 Dec 2025 00:00:00 -0500 - replace - http://creativecommons.org/licenses/by/4.0/ - Hayk L. Gevorgyan, Lekdar A. Gevorgian + Fri, 19 Dec 2025 00:00:00 -0500 + cross + http://creativecommons.org/licenses/by-nc-sa/4.0/ + Xiao-Wen Shang, Jian-Peng Dou, Feng Lu, Sen Lin, Hao Tang, Xian-Min Jin - Generation of Deep Ultraviolet Optical Vortices via Amplitude and Phase Spiral Zone Plates - https://arxiv.org/abs/2501.16950 - arXiv:2501.16950v3 Announce Type: replace -Abstract: We present the development and experimental implementation of diffractive optical elements designed to generate optical vortices in the deep ultraviolet range (from 260 to 266 nm). These elements, fabricated using advanced lithographic and etching techniques, facilitate the efficient transformation of Gaussian beams into twisted modes carrying orbital angular momentum. Experimental tests conducted using the laser driver of an RF photoinjector at JINR successfully demonstrate the generation of deep-ultraviolet optical vortices with a topological charge of l = 1. These findings underscore the potential of structured light in the deep ultraviolet range for applications in relativistic electron beam studies and beam manipulation technologies. - oai:arXiv.org:2501.16950v3 - physics.optics - physics.acc-ph - quant-ph - Fri, 12 Dec 2025 00:00:00 -0500 - replace + A Novel Proposal in Wind Turbine Blade Failure Detection: An Integrated Approach to Energy Efficiency and Sustainability + https://arxiv.org/abs/2512.16437 + arXiv:2512.16437v1 Announce Type: cross +Abstract: This paper presents a novel methodology for detecting faults in wind turbine blades using com-putational learning techniques. The study evaluates two models: the first employs logistic regression, which outperformed neural networks, decision trees, and the naive Bayes method, demonstrating its effectiveness in identifying fault-related patterns. The second model leverages clustering and achieves superior performance in terms of precision and data segmentation. The results indicate that clustering may better capture the underlying data characteristics compared to supervised methods. The proposed methodology offers a new approach to early fault detection in wind turbine blades, highlighting the potential of integrating different computational learning techniques to enhance system reliability. The use of accessible tools like Orange Data Mining underscores the practical application of these advanced solutions within the wind energy sector. Future work will focus on combining these methods to improve detection accuracy further and extend the application of these techniques to other critical components in energy infrastructure. + oai:arXiv.org:2512.16437v1 + cs.LG + physics.app-ph + Fri, 19 Dec 2025 00:00:00 -0500 + cross http://creativecommons.org/licenses/by/4.0/ - 10.1364/AO.578189 - A. S. Dyatlov, M. A. Nozdrin, A. N. Sergeev, N. E. Sheremet, S. S. Stafeev, D. V. Karlovets + 10.3390/app14178090 + Applied Sciences 2024, 14(17), 8090 + Jordan Abarca-Albores, Danna Cristina Guti\'errez Cabrera, Luis Antonio Salazar-Licea, Dante Ruiz-Robles, Jesus Alejandro Franco, Alberto-Jesus Perea-Moreno, David Mu\~noz-Rodr\'iguez, Quetzalcoatl Hernandez-Escobedo - MFC 5.0: An exascale many-physics flow solver - https://arxiv.org/abs/2503.07953 - arXiv:2503.07953v4 Announce Type: replace -Abstract: Many problems of interest in engineering, medicine, and the fundamental sciences rely on high-fidelity flow simulation, making performant computational fluid dynamics solvers a mainstay of the open-source software community. Previous work, MFC 3.0, was published, documented, and made open-source by Bryngelson et al. CPC (2021) features numerous physical features, numerical methods, and scalable infrastructure. MFC 5.0 is a significant update to MFC 3.0, featuring a broad set of well-established and novel physical models and numerical methods, as well as the introduction of GPU and APU (or superchip) acceleration. We exhibit state-of-the-art performance and ideal scaling on the first two exascale supercomputers, OLCF's Frontier and LLNL's El Capitan. Combined with MFC's single-accelerator performance, MFC achieves exascale computation in practice and has achieved the largest-to-date public CFD simulation at 200 trillion grid points, earning it a 2025 ACM Gordon Bell Prize finalist. New physical features include the immersed boundary method, $N$-fluid phase change, Euler-Euler and Euler-Lagrange sub-grid bubble models, fluid-structure interaction, hypo- and hyper-elastic materials, chemically reacting flow, two-material surface tension, magnetohydrodynamics (MHD), and more. Numerical techniques now represent the current state-of-the-art, including general relaxation characteristic boundary conditions, WENO variants, Strang splitting for stiff sub-grid flow features, and low Mach number treatments. Weak scaling to tens of thousands of GPUs on OLCF's Summit and Frontier, and LLNL's El Capitan, achieves efficiencies within 5% of ideal to over 90% of their respective system sizes. Strong scaling results for a 16-fold increase in device count show parallel efficiencies exceeding 90% on OLCF Frontier. - oai:arXiv.org:2503.07953v4 - physics.flu-dyn - cs.DC - Fri, 12 Dec 2025 00:00:00 -0500 - replace - http://creativecommons.org/licenses/by/4.0/ - Benjamin Wilfong, Henry A. Le Berre, Anand Radhakrishnan, Ansh Gupta, Daniel J. Vickers, Diego Vaca-Revelo, Dimitrios Adam, Haocheng Yu, Hyeoksu Lee, Jose Rodolfo Chreim, Mirelys Carcana Barbosa, Yanjun Zhang, Esteban Cisneros-Garibay, Aswin Gnanaskandan, Mauro Rodriguez Jr., Reuben D. Budiardja, Stephen Abbott, Tim Colonius, Spencer H. Bryngelson + Atomic forces from correlation energy functionals based on the adiabatic-connection fluctuation-dissipation theorem + https://arxiv.org/abs/2512.16460 + arXiv:2512.16460v1 Announce Type: cross +Abstract: We extend the capabilities of correlation energy functionals based on the adiabatic-connection fluctuation-dissipation theorem by implementing the analytical atomic forces within the random phase approximation (RPA), in the context of plane waves and pseudopotentials. Forces are calculated at self-consistency through the optimized effective potential method and the Hellmann-Feynman theorem. In addition, non-self-consistent RPA forces, starting from the PBE generalized gradient approximation, are evaluated using density functional perturbation theory. In both cases, we find forces of excellent numerical quality. Furthermore, for most molecules and solids studied, self-consistency is found to have a negligible impact on the computed geometries and vibrational frequencies. The RPA is shown to systematically improve over PBE and, by including the exact-exchange kernel within RPA + exchange (RPAx), through finite-difference total energy calculations, we obtain an accuracy comparable to advanced wavefunction methods. Finally, we estimate the anharmonic shift and provide accurate theoretical references based on RPA and RPAx for the zone-center optical phonon of diamond, silicon, and germanium. + oai:arXiv.org:2512.16460v1 + cond-mat.mtrl-sci + physics.chem-ph + physics.comp-ph + Fri, 19 Dec 2025 00:00:00 -0500 + cross + http://creativecommons.org/licenses/by-nc-sa/4.0/ + Damian Contant, Maria Hellgren - Microring resonator as a Rayleigh mirror for broadband laser-cavity comb generation - https://arxiv.org/abs/2503.09166 - arXiv:2503.09166v3 Announce Type: replace -Abstract: High-quality microring resonators (MRRs) have proven to be promising sources of optical combs generated from continuous-wave radiation. In addition to the primary comb that propagates along with the pump, Rayleigh scattering creates a comb that travels in the opposite direction. Normally, the scattering is a very weak, however, in the high-quality-factor MRR the power transferred to the backward-propagating comb can be quite significant. We demonstrate that the backward-propagating comb can be used as a feedback source for a fiber laser, effectively creating a nonlinear mirror for the laser cavity. By assembling a simple laser cavity comprising only active fiber and two mirrors, one of which is an integrated MRR, we show a robust self-starting comb generation with width exceeding 500 nm. We confirm the universal character of this approach for other types of microresonators, including whispering gallery mode resonators, by launching self-starting laser cavity combs with the crystalline toroidal cavity, coupled with a tapered fiber. This method provides significant simplification for the filter-driven laser cavity soliton generation, especially when free-space coupling is applied. - oai:arXiv.org:2503.09166v3 + Classical and quantum electromagnetic momentum in anisotropic optical waveguides + https://arxiv.org/abs/2512.16495 + arXiv:2512.16495v1 Announce Type: cross +Abstract: The guided modes supported by dielectric channel waveguides act as individual carriers of momentum. We show this by proving that the modes satisfy an orthogonality condition which relates to the momentum of the optical electromagnetic field, with a link to the more familiar power (energy) orthogonality. This result forms the basis for a rigorous, self-consistent procedure for the quantization of broadband guided electromagnetic fields in the typical channels used in integrated photonic circuits. Our work removes the existing theoretical gap between the classical solution of the Maxwell equations for guided fields and the intuitive understanding of photons in waveguides. The presented approach is valid for straight, lossless, and potentially anisotropic, dielectric waveguides of general shape, in the linear regime, and including material dispersion. Examples for the hybrid modes of a thin film lithium niobate strip waveguide are briefly discussed. + oai:arXiv.org:2512.16495v1 + quant-ph physics.optics - Fri, 12 Dec 2025 00:00:00 -0500 - replace - http://creativecommons.org/licenses/by/4.0/ - Aram A. Mkrtchyan (Skolkovo Institute of Science and Technology, Moscow, Russia), Anastasia S. Netrusova (Skolkovo Institute of Science and Technology, Moscow, Russia), Mikhail S. Mishevsky (Skolkovo Institute of Science and Technology, Moscow, Russia), Zohran Ali (Skolkovo Institute of Science and Technology, Moscow, Russia), Nikita Yu. Dmitriev (Russian Quantum Center, Moscow, Russia), Kirill N. Minkov (Russian Quantum Center, Moscow, Russia), Dmitry A. Chermoshentsev (Russian Quantum Center, Moscow, Russia), Albert G. Nasibulin (Skolkovo Institute of Science and Technology, Moscow, Russia), Igor A. Bilenko (Russian Quantum Center, Moscow, Russia), Yuriy G. Gladush (Skolkovo Institute of Science and Technology, Moscow, Russia) - - - Testing models for angular power spectra: A distribution-free approach - https://arxiv.org/abs/2504.16079 - arXiv:2504.16079v5 Announce Type: replace -Abstract: A novel goodness-of-fit strategy is introduced for testing models of angular power spectra with unknown parameters. Using this strategy, it is possible to assess the validity of such models without specifying the distribution of the angular power spectrum estimators. This holds under general conditions, ensuring the method's applicability in diverse applications. Moreover, the proposed solution overcomes the need for case-by-case simulations when testing different models, leading to notable computational advantages. - oai:arXiv.org:2504.16079v5 - physics.data-an - astro-ph.IM - Fri, 12 Dec 2025 00:00:00 -0500 - replace - http://creativecommons.org/licenses/by/4.0/ - Sara Algeri, Xiangyu Zhang, Erik Floden, Hongru Zhao, Galin L. Jones, Vuk Mandic, Jesse Miller - - - Optimization of 3D diamond detectors with graphitized electrodes based on an innovative numerical simulation - https://arxiv.org/abs/2505.12874 - arXiv:2505.12874v3 Announce Type: replace -Abstract: Future experiments at hadron colliders require an evolution of the tracking sensors to ensure sufficient radiation hardness as well as space and time resolution to handle unprecedented particle fluxes. 3D diamond sensors with laser-graphitized electrodes are promising candidates due to their strong binding energy, small atomic number, and high carrier mobility. However, the high resistance of the engraved electrodes delays the propagation of the induced signals towards the readout electronics, thereby degrading the precision of the timing measurements. So far, this effect has been the dominant factor limiting the time resolution of these devices, with other contributions, such as those due to electric field inhomogeneities or electronic noise, typically neglected. Recent advancements in graphitization technology, however, motivate a renewed effort in modeling signal generation in 3D diamond detectors, to achieve more reliable predictions. To this purpose, we apply an extended version of the Ramo-Shockley theorem, describing the effect of signal propagation as a time-dependent weighting potential, obtained by numerically solving the Maxwell's equations in a quasi-static approximation. We developed a custom spectral method solver and validated it against COMSOL MultiPhysics. The response of the modeled sensor to a beam of particles is then simulated using Garfield++ and is compared to the data acquired in a beam test carried on in 2021 by the TimeSPOT Collaboration at the SPS, at CERN. Based on the results obtained with this simulation workflow, we conclude that reducing the resistivity of the graphitic columns remains the priority for significantly improving the time resolution of 3D diamond detectors. Once achieved, optimization of the detector geometry and readout electronics design will become equally important steps to further enhance the timing performance of these devices. - oai:arXiv.org:2505.12874v3 - physics.ins-det - Fri, 12 Dec 2025 00:00:00 -0500 - replace + Fri, 19 Dec 2025 00:00:00 -0500 + cross http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Lucio Anderlini, Alessandro Bombini, Clarissa Buti, Djunes Janssens, Stefano Lagomarsino, Giovanni Passaleva, Michele Veltri + Denis Kopylov, Manfred Hammer - Modelling cosmic-ray transport: magnetised versus unmagnetised motion in astrophysical magnetic turbulence - https://arxiv.org/abs/2505.18155 - arXiv:2505.18155v3 Announce Type: replace -Abstract: Cosmic-ray transport in turbulent astrophysical environments remains a multifaceted problem and, despite decades of study, the impact of complex magnetic field geometry -- evident in simulations and observations -- has only recently received more focussed attention. To understand how ensemble-averaged transport behaviour emerges from the intricate interactions between cosmic rays and structured magnetic turbulence, we run test-particle experiments in snapshots of a strongly turbulent magnetohydrodynamics simulation. We characterise particle--turbulence interactions via the gyro radii of particles and their experienced field-line curvatures, which reveals two distinct transport modes: magnetised motion, where particles are tightly bound to strong coherent flux tubes and undergo large-scale mirroring; and unmagnetised motion, characterised by chaotic scattering through weak and highly tangled regions of the magnetic field. We formulate an effective stochastic process for each mode: compound subdiffusion with long mean free paths for magnetised motion, and a Langevin process with short mean free paths for unmagnetised motion. A combined stochastic walker that alternates between these two modes accurately reproduces the mean squared displacements observed in the test-particle data. Our results emphasise the critical role of coherent magnetic structures in comprehensively understanding cosmic-ray transport and lay a foundation for developing a theory of geometry-mediated transport. - oai:arXiv.org:2505.18155v3 - physics.plasm-ph - astro-ph.HE - Fri, 12 Dec 2025 00:00:00 -0500 - replace + Cosmology with non-linear barotropic Israel-Stewart fluid with causal relaxation time + https://arxiv.org/abs/2512.16502 + arXiv:2512.16502v1 Announce Type: cross +Abstract: We derive an extended expression for the relaxation time of a barotropic Israel-Stewart (IS) fluid using the non-linear causality constraint, and propose a new formulation for modeling causal viscous dissipation in barotropic fluids. With this generalized relaxation time, the non-linear IS equation simplifies to a first-order non-linear expression connecting bulk viscous pressure and energy density, which remains valid in any homogeneous and isotropic spacetime. In the case of spatially flat Friedmann universe, adopting this extended relation in the generalized non-linear IS theory, provides new class of analytical solutions in both, the linear, and the non-linear regimes. We also find that, the resulting effective equation of state in the linear regime naturally reproduces the generalized polytropic form which is often introduced phenomenologically in literature. Resulting dynamical implications are investigated and the constraints necessary for ensuring an acceptable evolutionary behavior for the fluid are determined. A detailed dynamical system analysis of the coupled Einstein-Israel-Stewart (EIS) system is also performed. Finally, we solve the coupled EIS equations numerically, and show that the model can support a transient Hubble slow-roll expansion phase with a smooth exit to a radiation-dominated universe, which is challenging to obtain in standard inflationary models. + oai:arXiv.org:2512.16502v1 + gr-qc + astro-ph.CO + hep-ph + physics.flu-dyn + Fri, 19 Dec 2025 00:00:00 -0500 + cross http://creativecommons.org/licenses/by/4.0/ - 10.1017/S0022377825100883 - Jeremiah L\"ubke, Patrick Reichherzer, Sophie Aerdker, Frederic Effenberger, Mike Wilbert, Horst Fichtner, Rainer Grauer + Vishnu A Pai, Titus K Mathew - Simulation of MAPS and a MAPS-based Inner Tracker for the Super Tau-Charm Facility - https://arxiv.org/abs/2506.03712 - arXiv:2506.03712v2 Announce Type: replace -Abstract: Monolithic Active Pixel Sensors (MAPS) are a promising detector candidate for the inner tracker of the Super Tau-Charm Facility (STCF). To evaluate the performance of MAPS and the MAPS-based inner tracker, a dedicated simulation workflow has been developed, offering essential insights for detector design and optimization. - The intrinsic characteristics of MAPS, designed using several fabrication processes and pixel geometries, were investigated through a combination of Technology Computer Aided Design (TCAD) and Monte Carlo simulations. Simulations were conducted with both minimum ionizing particles and $^{55}$Fe X-rays to assess critical parameters such as detection efficiency, cluster size, spatial resolution, and charge collection efficiency. Based on these evaluations, a MAPS sensor featuring a strip-like pixel and a high-resistivity epitaxial layer is selected as the baseline sensor design for the STCF inner tracker due to its excellent performance. - Using this optimized MAPS design, a three-layer MAPS-based inner tracker was modeled and simulated. The simulation demonstrated an average detection efficiency exceeding 99%, spatial resolutions of 44.8$\rm{\mu m}$ in the $z$ direction and 8.2$\rm{\mu m}$ in the $r-\phi$ direction, and an intrinsic sensor time resolution of 5.9ns for 1GeV/c $\mu^-$ particles originating from the interaction point. These promising results suggest that the MAPS-based inner tracker fulfills the performance requirements of the STCF experiment. - oai:arXiv.org:2506.03712v2 - physics.ins-det - hep-ex - Fri, 12 Dec 2025 00:00:00 -0500 - replace - http://creativecommons.org/publicdomain/zero/1.0/ - Ruiyang Zhang, Dongwei Xuan, Jiajun Qin, Lei Zhao, Le Xiao, Xiangming Sun, Lailin Xu, Jianbei Liu - - - Application-specific machine-learned interatomic potentials: exploring the trade-off between DFT convergence, MLIP expressivity, and computational cost - https://arxiv.org/abs/2506.05646 - arXiv:2506.05646v2 Announce Type: replace -Abstract: Machine-learned interatomic potentials (MLIPs) are revolutionizing computational materials science and chemistry by offering an efficient alternative to {\em ab initio} molecular dynamics (MD) simulations. However, fitting high-quality MLIPs remains a challenging, time-consuming, and computationally intensive task where numerous trade-offs have to be considered, e.g., How much and what kind of atomic configurations should be included in the training set? Which level of {\em ab initio} convergence should be used to generate the training set? Which loss function should be used for fitting the MLIP? Which machine learning architecture should be used to train the MLIP? The answers to these questions significantly impact both the computational cost of MLIP training and the accuracy and computational cost of subsequent MLIP MD simulations. In this study, we use a configurationally diverse beryllium dataset and quadratic spectral neighbor analysis potential. We demonstrate that joint optimization of energy versus force weights, training set selection strategies, and convergence settings of the {\em ab initio} reference simulations, as well as model complexity can lead to a significant reduction in the overall computational cost associated with training and evaluating MLIPs. This opens the door to computationally efficient generation of high-quality MLIPs for a range of applications which demand different accuracy versus training and evaluation cost trade-offs. - oai:arXiv.org:2506.05646v2 - physics.comp-ph - cond-mat.mtrl-sci - Fri, 12 Dec 2025 00:00:00 -0500 - replace + Current-Induced Modulation of Spin-Wave Propagation in a Y-Junction via Transverse Spin-Transfer Torque + https://arxiv.org/abs/2512.16563 + arXiv:2512.16563v1 Announce Type: cross +Abstract: We report the transverse control of spin-wave propagation in the configuration where the spin-wave wavevector k is perpendicular to the charge-current density J. Building on theoretical predictions of spin-wave refraction by nonuniform spin-polarized currents, and guided by micromagnetic simulations used to optimize the device geometry and current distribution, we experimentally explore a Y-shaped Permalloy structure in which a locally injected current perturbs the spin-wave dispersion. Measurements reveal current-dependent amplitude differences between the two output branches, providing initial experimental indications consistent with transverse, spin-transfer-torque-driven deflection. Although the magnitude of the effect is modest and accompanied by significant uncertainties, the observed trends qualitatively follow expectations from the simulations. These results demonstrate the feasibility of influencing spin-wave routing through local current injection and establish a proof-of-concept basis for current-controlled manipulation of spin-wave propagation in reconfigurable magnonic circuits. + oai:arXiv.org:2512.16563v1 + cond-mat.mes-hall + physics.app-ph + Fri, 19 Dec 2025 00:00:00 -0500 + cross http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - 10.1039/d5dd00294j - Digital Discovery, 2026 - Ilgar Baghishov, Jan Janssen, Graeme Henkelman, Danny Perez + Lorenzo Gnoatto, Rai M. Menezes, Artim L. Bassant, Rembert A. Duine, Milorad V. Milosevic, Reinoud Lavrijsen - AI-Informed Model Analogs for Subseasonal-to-Seasonal Prediction - https://arxiv.org/abs/2506.14022 - arXiv:2506.14022v2 Announce Type: replace -Abstract: Subseasonal-to-seasonal forecasting is crucial for public health, disaster preparedness, and agriculture, and yet it remains a particularly challenging timescale to predict. We explore the use of an interpretable AI-informed model analog forecasting approach, previously employed on longer timescales, to improve S2S predictions. Using an artificial neural network, we learn a mask of weights to optimize analog selection and showcase its versatility across three varied prediction tasks: 1) classification of Week 3-4 Southern California summer temperatures; 2) regional regression of Month 1 midwestern U.S. summer temperatures; and 3) classification of Month 1-2 North Atlantic wintertime upper atmospheric winds. The AI-informed analogs outperform traditional analog forecasting approaches, as well as climatology and persistence baselines, for deterministic and probabilistic skill metrics on both climate model and reanalysis data. We find the analog ensembles built using the AI-informed approach also produce better predictions of temperature extremes and improve representation of forecast uncertainty. Finally, by using an interpretable-AI framework, we analyze the learned masks of weights to better understand S2S sources of predictability. - oai:arXiv.org:2506.14022v2 - physics.ao-ph + Riemannian Stochastic Interpolants for Amorphous Particle Systems + https://arxiv.org/abs/2512.16607 + arXiv:2512.16607v1 Announce Type: cross +Abstract: Modern generative models hold great promise for accelerating diverse tasks involving the simulation of physical systems, but they must be adapted to the specific constraints of each domain. Significant progress has been made for biomolecules and crystalline materials. Here, we address amorphous materials (glasses), which are disordered particle systems lacking atomic periodicity. Sampling equilibrium configurations of glass-forming materials is a notoriously slow and difficult task. This obstacle could be overcome by developing a generative framework capable of producing equilibrium configurations with well-defined likelihoods. In this work, we address this challenge by leveraging an equivariant Riemannian stochastic interpolation framework which combines Riemannian stochastic interpolant and equivariant flow matching. Our method rigorously incorporates periodic boundary conditions and the symmetries of multi-component particle systems, adapting an equivariant graph neural network to operate directly on the torus. Our numerical experiments on model amorphous systems demonstrate that enforcing geometric and symmetry constraints significantly improves generative performance. + oai:arXiv.org:2512.16607v1 + stat.ML + cond-mat.stat-mech cs.LG - Fri, 12 Dec 2025 00:00:00 -0500 - replace - http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Jacob B. Landsberg, Elizabeth A. Barnes, Matthew Newman - - - XtalOpt Version 14: Variable-Composition Crystal Structure Search for Functional Materials Through Pareto Optimization - https://arxiv.org/abs/2506.17246 - arXiv:2506.17246v3 Announce Type: replace -Abstract: Version 14 of XtalOpt, an evolutionary multi-objective global optimization algorithm for crystal structure prediction, is now available for download from its official website https://xtalopt.github.io, and the Computer Physics Communications Library. The new version of the code is designed to perform a ground state search for crystal structures with variable compositions by integrating a suite of ab initio methods alongside classical and machine-learning potentials for structural relaxation. The multi-objective search framework has been enhanced through the introduction of Pareto optimization, enabling efficient discovery of functional materials. Herein, we describe the newly implemented methodologies, provide detailed instructions for their use, and present an overview of additional improvements included in the latest version of the code. - oai:arXiv.org:2506.17246v3 physics.comp-ph - cond-mat.mtrl-sci - Fri, 12 Dec 2025 00:00:00 -0500 - replace + Fri, 19 Dec 2025 00:00:00 -0500 + cross http://creativecommons.org/licenses/by/4.0/ - Samad Hajinazar, Eva Zurek + Louis Grenioux, Leonardo Galliano, Ludovic Berthier, Giulio Biroli, Marylou Gabri\'e - Unraveling Self-Similar Energy Transfer Dynamics: a Case Study for 1D Burgers System - https://arxiv.org/abs/2507.12764 - arXiv:2507.12764v2 Announce Type: replace -Abstract: In this work we consider the problem of constructing initial conditions for a flow model such that the resulting flow evolution leads to a self-similar energy cascade consistent with Kolmogorov's statistical theory of turbulence. As a first step in this direction, we focus on the one-dimensional viscous Burgers equation as a toy model. Its solutions exhibiting self-similar behavior, in a precisely-defined sense, are found by framing this problems in terms of PDE-constrained optimization. The main physical parameters are the time window over which self-similar behavior is sought (equal to approximately one eddy turnover time), viscosity (inversely proportional to the ``Reynolds number") and an integer parameter characterizing the distance in the Fourier space over which self-similar interactions occur. Local solutions to this nonconvex PDE optimization problems are obtained with a state-of-the-art adjoint-based gradient method. Two distinct families of solutions, termed viscous and inertial, are identified and are distinguished primarily by the behavior of enstrophy which, respectively, uniformly decays and grows in the two cases. The physically meaningful and appropriately self-similar inertial solutions are found only when a sufficiently small viscosity is considered. These flows achieve the self-similar behaviour by a uniform steepening of the wave fronts present in the solutions. The results obtained demonstrate that the proposed methodology may be used to search for self-similar behavior in more complex flow models, including shell models, 2D turbulence and, ultimately, 3D turbulence. - oai:arXiv.org:2507.12764v2 - physics.flu-dyn - math.AP - Fri, 12 Dec 2025 00:00:00 -0500 - replace - http://creativecommons.org/licenses/by/4.0/ - Pritpal Matharu, Bartosz Protas, Tsuyoshi Yoneda + Controlling Spin-Waves by Inhomogeneous Spin-Transfer Torques + https://arxiv.org/abs/2512.16612 + arXiv:2512.16612v1 Announce Type: cross +Abstract: We investigate the interplay between spin currents and spin waves in nanofabricated Permalloy waveguides with geometrical constrictions. Using propagating spin-wave spectroscopy, micromagnetic simulations, and analytical modeling, we provide experimental evidence that spin-wave phase can be modulated by inhomogeneous spin-transfer torques generated by current-density gradients shaped by the constriction geometry. Narrower constrictions enhance these gradients and modify the internal field for Damon-Eshbach spin waves, resulting in pronounced changes in spin-wave group velocity and phase. To our knowledge, this constitutes the first demonstration of deterministic phase modulation via engineered nonuniform spin-transfer torques. Beyond enabling a scalable route to magnonic interferometry - a building block for spin-wave-based computing - our findings establish a platform to control spin-wave dynamics in spatially varying current landscapes, relevant for analogue-gravity experiments in condensed matter systems. + oai:arXiv.org:2512.16612v1 + cond-mat.mes-hall + physics.app-ph + Fri, 19 Dec 2025 00:00:00 -0500 + cross + http://arxiv.org/licenses/nonexclusive-distrib/1.0/ + Lorenzo Gnoatto, Jean F. O. da Silva, Artim L. Bassant, Rai M. Menezes, Rembert A. Duine, Milorad V. Milossevic, Reinoud Lavrijsen - Role of interfacial stabilization in the Rayleigh-B\'enard convection of liquid-liquid dispersions - https://arxiv.org/abs/2507.22214 - arXiv:2507.22214v2 Announce Type: replace -Abstract: Based on mesoscale lattice Boltzmann numerical simulations, we characterize the Rayleigh-B\'enard (RB) convective dynamics of dispersions of liquid droplets in another liquid phase. Our numerical methodology allows us to modify the droplets' interfacial properties to mimic the presence of an emulsifier (e.g., a surfactant), resulting in a positive disjoining pressure that stabilizes the droplets against coalescence. To appreciate the effects of this interfacial stabilization on the RB convective dynamics, we carry out a comparative study between a proper emulsion, i.e., a system where the stabilization mechanism is present (stabilized liquid-liquid dispersion), and a system where the stabilization mechanism is absent (non-stabilized liquid-liquid dispersion). The study is conducted by systematically changing both the volume fraction, $\phi$, and the Rayleigh number, Ra. We find that the morphology of the two systems is dramatically different due to the different interfacial properties. However, the two systems exhibit similar global heat transfer properties, expressed via the Nusselt number Nu. Significant differences in heat transfer emerge at smaller scales, which we analyze via the Nusselt number defined at mesoscales, Nu$_{\mathrm{mes}}$. In particular, stabilized systems exhibit more intense mesoscale heat flux fluctuations due to the persistence of fluid velocity fluctuations down to small scales, which are instead dissipated in the interfacial dynamics of non-stabilized dispersions. For fixed Ra, the difference in mesoscale heat flux fluctuations depends non-trivially on $\phi$, featuring a maximum in the range $0.1 < \phi < 0.2$. Taken all together, our results highlight the role of interfacial physics in mesoscale convective heat transfer of complex fluids. - oai:arXiv.org:2507.22214v2 - physics.flu-dyn - Fri, 12 Dec 2025 00:00:00 -0500 - replace - http://creativecommons.org/licenses/by/4.0/ - 10.1103/5b6w-8xbb - Physical Review Fluids 10, 124305 (2025) - Francesca Pelusi, Andrea Scagliarini, Mauro Sbragaglia, Massimo Bernaschi, Roberto Benzi + Wigner polarons reveal Wigner crystal dynamics in a monolayer semiconductor + https://arxiv.org/abs/2512.16631 + arXiv:2512.16631v1 Announce Type: cross +Abstract: Wigner crystals, lattices made purely of electrons, are a quintessential paradigm of studying correlation-driven quantum phase transitions. Despite decades of research, the internal dynamics of Wigner crystals has remained extremely challenging to access, with most experiments probing only static order or collective motion. Here, we establish monolayer WSe2 as a new materials platform to host zero-field Wigner crystals and then demonstrate that exciton spectroscopy provides a direct means to probe both static and dynamic properties of these electron lattices. We uncover striking optical resonances that we identify as Wigner polarons, quasiparticles formed when the electron lattice is locally distorted by exciton-Wigner crystal coupling. We further achieve all-optical control of spins in the Wigner crystal, directly probing valley-dependent Wigner polaron scattering well above the magnetic ordering temperature and in the absence of any external magnetic field. Finally, we demonstrate optical melting of the Wigner crystal and observe intriguingly different responses of the umklapp (static) and Wigner polaron (dynamic) resonances to optical excitation. Our results open up exciting new avenues for elucidating electron dynamics and achieving ultrafast optical control of interaction-driven quantum phase transitions in strongly correlated electron systems. + oai:arXiv.org:2512.16631v1 + cond-mat.mes-hall + cond-mat.mtrl-sci + cond-mat.str-el + physics.optics + Fri, 19 Dec 2025 00:00:00 -0500 + cross + http://arxiv.org/licenses/nonexclusive-distrib/1.0/ + Lifu Zhang, Liuxin Gu, Haydn S. Adlong, Arthur Christianen, Eugen Dizer, Ruihao Ni, Rundong Ma, Suji Park, Houk Jang, Takashi Taniguchi, Kenji Watanabe, Ilya Esterlis, Richard Schmidt, Atac Imamoglu, You Zhou - Size-Dependent Skin Effect Transitions in Weakly Coupled Non-Reciprocal Chains - https://arxiv.org/abs/2508.02273 - arXiv:2508.02273v2 Announce Type: replace -Abstract: Non-Hermitian systems exhibit unique boundary phenomena absent in their Hermitian counterparts, most notably the non-Hermitian skin effect (NHSE). In this work, we explore a lattice model consisting of two coupled non-reciprocal chains, focusing on the interplay between system size, inter-chain coupling, and spectral topology. Using both analytical and numerical approaches, we systematically examine the evolution of the complex energy spectra and spectral winding numbers under periodic and open boundary conditions. Our results uncover a variety of size-dependent localization transitions, including the emergence and instability of concurrent bipolar skin effects in the $W=0$ region, and their crossover to unipolar and conventional bipolar NHSE as the system size increases. Notably, we demonstrate that these size-dependent behaviors persist even beyond the weak-coupling regime, highlighting their universality in non-Hermitian systems with complex spectral structures. This study provides insights into the mechanisms governing skin effects and offers practical guidelines for engineering non-Hermitian topological phases in synthetic lattices. - oai:arXiv.org:2508.02273v2 + Shaping Dynamics Through Memory: A Study of Reservoir Profiles in Open Quantum Systems + https://arxiv.org/abs/2512.16657 + arXiv:2512.16657v1 Announce Type: cross +Abstract: In this work, we investigate how different reservoir memory profiles influence the dynamical evolution of a single waveguide coupled to an external environment. We compare three representative memory kernels: Lorentzian, Gaussian and Uniform, highlighting their distinct spatial correlations and their impact on system behavior. We compute the transmission amplitude, transparency properties, as well as long-time behavior of the system under each memory model. To quantify deviations from Markovian dynamics, we employ a non-Markovianity measure based on information backflow, allowing a direct comparison between the structured reservoirs and the Markovian limit. Our results reveal clear signatures of memoryless-induced modifications in the transmission spectrum and demonstrate how specific reservoir profiles enhance or suppress non-Markovian effects. + oai:arXiv.org:2512.16657v1 + quant-ph physics.optics - cond-mat.other - Fri, 12 Dec 2025 00:00:00 -0500 - replace + Fri, 19 Dec 2025 00:00:00 -0500 + cross http://creativecommons.org/licenses/by/4.0/ - 10.1103/bmq5-7tf6 - Phys. Rev. B 112, 235122 (2025) - Yixuan Li, Linhu Li, Zhihao Xu + J. R. Silva, C. Antunis B. S. Santos - Collective contributions to polarization in political voting - https://arxiv.org/abs/2508.02496 - arXiv:2508.02496v3 Announce Type: replace -Abstract: Politics around the world exhibits increasing polarization, demonstrated in part by rigid voting configurations in institutions like legislatures or courts. A crux of polarization is separation along a unidimensional ideological axis, but voting behavior is in reality more complex, with other signatures of collective order. We extend a foundational, statistical physics framework, restricted Boltzmann machines, to explain the full complexity of voting. The models we propose are minimal, fit strongly correlated voting data, and have parameters that transparently give vote probabilities. The model accounts for multi-dimensional voter preferences and the context in which such preferences are expressed to disentangle individual from collective contributions; for example, legislative bills can negotiate multiple issues, whose appeals add up or compete for individual votes. With the example of the U.S. Senate, we find that senators have multi-dimensional preferences, and, as one consequence, non-polarized coalitions coexist with polarized ones. Increasing polarization is predominantly explained by fewer votes that elicit bipartisan coalitions. We show that these accounts can be consistent, if far more parsimonious, than interaction-driven order. The findings highlight the collective choice of the content of and the rules of voting in the ebb and flow of polarization. - oai:arXiv.org:2508.02496v3 - physics.soc-ph - Fri, 12 Dec 2025 00:00:00 -0500 - replace + How accurate are foundational machine learning interatomic potentials for heterogeneous catalysis? + https://arxiv.org/abs/2512.16702 + arXiv:2512.16702v1 Announce Type: cross +Abstract: Foundational machine learning interatomic potentials (MLIPs) are being developed at a rapid pace, promising closer and closer approximation to ab initio accuracy. This unlocks the possibility to simulate much larger length and time scales. However, benchmarks for these MLIPs are usually limited to ordered, crystalline and bulk materials. Hence, reported performance does not necessarily accurately reflect MLIP performance in real applications such as heterogeneous catalysis. Here, we systematically analyze zero-shot performance of 80 different MLIPs, evaluating tasks typical for heterogeneous catalysis across a range of different data sets, including adsorption and reaction on surfaces of alloyed metals, oxides, and metal-oxide interfacial systems. We demonstrate that current-generation foundational MLIPs can already perform at high accuracy for applications such as predicting vacancy formation energies of perovskite oxides or zero-point energies of supported nanoclusters. However, limitations also exist. We find that many MLIPs catastrophically fail when applied to magnetic materials, and structure relaxation in the MLIP generally increases the energy prediction error compared to single-point evaluation of a previously optimized structure. Comparing low-cost task-specific models to foundational MLIPs, we highlight some core differences between these model approaches and show that -- if considering only accuracy -- these models can compete with the current generation of best-performing MLIPs. Furthermore, we show that no single MLIP universally performs best, requiring users to investigate MLIP suitability for their desired application. + oai:arXiv.org:2512.16702v1 + cond-mat.mtrl-sci + cs.LG + physics.chem-ph + Fri, 19 Dec 2025 00:00:00 -0500 + cross http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Edward D. Lee + Luuk H. E. Kempen, Raffaele Cheula, Mie Andersen - Epidemic threshold and localization of the SIS model on directed complex networks - https://arxiv.org/abs/2508.06332 - arXiv:2508.06332v2 Announce Type: replace -Abstract: We study the susceptible-infected-susceptible (SIS) model on directed complex networks within the quenched mean-field approximation. Combining results from random matrix theory with an analytic approach to the distribution of fixed-point infection probabilities, we derive the phase diagram and show that the model exhibits a nonequilibrium phase transition between the absorbing and endemic phases for $c \geq \lambda^{-1}$, where $c$ is the mean degree and $\lambda$ the average infection rate. Interestingly, the critical line is independent of the degree distribution but is highly sensitive to the form of the infection-rate distribution. We further show that the inverse participation ratio of infection probabilities diverges near the epidemic threshold, indicating that the disease may become localized on a small fraction of nodes. These results provide a systematic characterization of how network heterogeneities shape epidemic spreading on directed contact networks within the quenched mean-field approximation. - oai:arXiv.org:2508.06332v2 - physics.soc-ph - cond-mat.dis-nn + Correlation between the first-reaction time and the acquired boundary local time + https://arxiv.org/abs/2512.16747 + arXiv:2512.16747v1 Announce Type: cross +Abstract: We investigate the statistical correlation between the first-reaction time of a diffusing particle and its boundary local time accumulated until the reaction event. Since the reaction event occurs after multiple encounters of the particle with a partially reactive boundary, the boundary local time as a proxy for the number of such encounters is not independent of, but intrinsically linked to, the first-reaction time. We propose a universal theoretical framework to derive their joint probability density and, in particular, the correlation coefficient. To illustrate the dependence of these correlations on the boundary reactivity and shape, we obtain explicit analytical solutions for several basic domains. The analytical results are complemented by Monte Carlo simulations, which we employ to examine the role of interior obstacles on correlations in disordered media. Applications of these statistical results in chemical physics are discussed + oai:arXiv.org:2512.16747v1 cond-mat.stat-mech - physics.bio-ph - Fri, 12 Dec 2025 00:00:00 -0500 - replace - http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - 10.1103/wg82-f4lf - Phys. Rev. E 112, 064303 (2025) - Vin\'icius B. M\"uller, Fernando L. Metz - - - Identifying efficient routes to laminarization: an optimization approach - https://arxiv.org/abs/2508.08519 - arXiv:2508.08519v2 Announce Type: replace -Abstract: The nonlinear and chaotic nature of turbulent flows poses a major challenge for designing effective control strategies to maintain or induce low-drag laminar states. Traditional linear methods often fail to capture the complex dynamics governing transitions between laminar and turbulent regimes. In this work, we introduce the concept of the minimal seed for relaminarization-the closest point to a reference state in the turbulent region of the state space that triggers a direct transition to laminar flow without a chaotic transient. We formulate the identification of this optimal perturbation as a fully nonlinear optimization problem and develop a numerical framework based on a multi-step penalty method to compute it. Applying this framework to a nine-mode model of a sinusoidal shear flow, we compute the minimal seeds for both transition to turbulence and relaminarization. While both of these minimal seeds lie infinitesimally close to the laminar-turbulent boundary-the edge of chaos-they are generally unrelated and lie in distant and qualitatively distinct regions of state space, thereby providing different insights into the flow's underlying structure. We find that the optimal perturbation for triggering transition is primarily in the direction of the mode representing streamwise vortices (rolls), whereas the optimal perturbation for relaminarization is distributed across multiple modes without strong contributions in the roll or streak directions. By analyzing trajectories originating from these minimal seeds, we find that both transition and laminarization behavior are controlled by the stable and unstable manifolds of a periodic orbit on the edge of chaos. The laminarizing trajectory obtained from the minimal seed for relaminarization provides an efficient pathway out of turbulence and can inform the design and evaluation of flow control strategies aimed at inducing laminarization. - oai:arXiv.org:2508.08519v2 - physics.flu-dyn - nlin.CD - Fri, 12 Dec 2025 00:00:00 -0500 - replace - http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Jake Buzhardt, Michael D. Graham - - - Metatensor and metatomic: foundational libraries for interoperable atomistic machine learning - https://arxiv.org/abs/2508.15704 - arXiv:2508.15704v3 Announce Type: replace -Abstract: Incorporation of machine learning (ML) techniques into atomic-scale modeling has proven to be an extremely effective strategy to improve the accuracy and reduce the computational cost of simulations. It also entails conceptual and practical challenges, as it involves combining very different mathematical foundations, as well as software ecosystems that are very well developed in their own right, but do not share many commonalities. To address these issues and facilitate the adoption of ML in atomistic simulations, we introduce two dedicated software libraries. The first one, metatensor, provides multi-platform and multi-language storage and manipulation of arrays with many potentially sparse indices, designed from the ground up for atomistic ML applications. By combining the actual values with metadata that describes their nature and that facilitates the handling of geometric information and gradients with respect to the atomic positions, metatensor provides a common framework to enable data sharing between ML software -- typically written in Python -- and established atomistic modeling tools -- typically written in Fortran, C or C++. The second library, metatomic, provides an interface to store an atomistic ML model and metadata about this model in a portable way, facilitating the implementation, training and distribution of models, and their use across different simulation packages. We showcase a growing ecosystem of tools, including low-level libraries, training utilities, and interfaces with existing software packages that demonstrate the effectiveness of metatensor and metatomic in bridging the gap between traditional simulation software and modern ML frameworks. - oai:arXiv.org:2508.15704v3 physics.chem-ph - Fri, 12 Dec 2025 00:00:00 -0500 - replace - http://creativecommons.org/licenses/by-nc-sa/4.0/ - Filippo Bigi, Joseph W. Abbott, Philip Loche, Arslan Mazitov, Davide Tisi, Marcel F. Langer, Alexander Goscinski, Paolo Pegolo, Sanggyu Chong, Rohit Goswami, Pol Febrer, Sofiia Chorna, Matthias Kellner, Michele Ceriotti, Guillaume Fraux - - - Two-dimensional electronic spectra from trajectory-based dynamics: pure-state Ehrenfest, spin-mapping, and mean classical path approaches - https://arxiv.org/abs/2508.19377 - arXiv:2508.19377v2 Announce Type: replace -Abstract: Two-dimensional electronic spectroscopy (2DES) provides a detailed picture of electronically nonadiabatic dynamics that can be interpreted with the aid of simulations. Here, we develop and contrast trajectory-based nonadiabatic dynamics approaches for simulating 2DES spectra. First, we argue that an improved pure-state Ehrenfest approach can be constructed by decomposing the initial coherence into a sum of equatorial pure states that contain equal contributions from the states in the coherence. We then use this framework to show how one can obtain a more accurate, but computationally more expensive, approximation to the third-order 2DES response function by replacing Ehrenfest dynamics with spin mapping during the pump-probe delay time. We end by comparing and contrasting the accuracy of these methods and the simpler mean classical path approximation in reproducing the exact linear, pump-probe, and 2DES spectra of two Frenkel exciton models: a coupled dimer system and the Fenna-Matthews-Olson (FMO) complex. - oai:arXiv.org:2508.19377v2 - physics.chem-ph - Fri, 12 Dec 2025 00:00:00 -0500 - replace - http://creativecommons.org/licenses/by/4.0/ - 10.1063/5.0299204 - J. Chem. Phys. 163, 214111 (2025) - Annina Z. Lieberherr, Joseph Kelly, Johan E. Runeson, Thomas E. Markland, David E. Manolopoulos - - - Charting the Luminosity Capabilities of the CERN Large Hadron Collider with Various Nuclear Species - https://arxiv.org/abs/2508.19653 - arXiv:2508.19653v3 Announce Type: replace -Abstract: The Large Hadron Collider (LHC) at CERN has been instrumental in recent advances in experimental high energy physics by colliding beams of protons and heavier nuclei at unprecedented energies. The present heavy-ion programme is based mainly on colliding lead nuclei. For future ion runs, there is strong interest to achieve a significantly higher integrated nucleon-nucleon luminosity, which might be achieved through collisions of species other than Pb. In this paper, we explore the nucleon-nucleon luminosity projections in the LHC for a selection of ion species ranging from He to Xe, and including Pb as reference. Alternative beam production schemes are investigated as a way to mitigate effects such as space charge that degrade the beam quality in the LHC injectors. In the most optimistic scenarios, we find up to about a factor~4 improvement in integrated nucleon-nucleon luminosity for a typical future one-month run, with respect to the present Pb programme. We also outline a future study programme and experiments to test the assumptions and refine the simulated projections put forward in this article. - oai:arXiv.org:2508.19653v3 - physics.acc-ph - nucl-ex - Fri, 12 Dec 2025 00:00:00 -0500 - replace - http://creativecommons.org/licenses/by/4.0/ - 10.1016/j.nima.2025.171118 - Nucl. Instrum. Methods Phys. Res., Sect. A 1083, 171118 (2026) - E. Waagaard, R. Bruce, R. Alemany Fernandez, H. Bartosik, J. M. Jowett, N. Triantafyllou - - - Kinetic Turing Instability and Emergent Spectral Scaling in Chiral Active Turbulence - https://arxiv.org/abs/2508.21012 - arXiv:2508.21012v4 Announce Type: replace -Abstract: The spontaneous emergence of coherent structures from chaotic backgrounds is a hallmark of active biological swarms. We investigate this self-organization by simulating an ensemble of polar chiral active agents that couple locally via a Kuramoto interaction. We demonstrate that the system's transition from chaos to active turbulence is characterized by quantized loop phase currents and coherent clustering, and that this transition is strictly governed by a kinetic Turing instability. By deriving the continuum kinetic theory for the model, we identify that the competition between local phase-locking and active agent motility selects a critical structural wavenumber. The instability drives the system into a state of developed turbulence that exhibits stable, robust power-laws in spectral density, suggestive of universality and consistent with observations from a broad range of turbulent phenomena. Our results bridge the gap between discrete chimera states and continuous fluid turbulence, suggesting that the statistical laws of active matter can arise from fundamental kinetic instability criteria. - oai:arXiv.org:2508.21012v4 - physics.comp-ph - nlin.CD - Fri, 12 Dec 2025 00:00:00 -0500 - replace - http://creativecommons.org/licenses/by-nc-sa/4.0/ - Magnus F Ivarsen - - - A multiscale numerical approach to investigate interfacial mass transfer in three phase flow: application to metallurgical bottom-blown ladles - https://arxiv.org/abs/2509.05033 - arXiv:2509.05033v2 Announce Type: replace -Abstract: We use direct numerical simulation (DNS) to investigate mass transfer between liquid steel and slag during a metallurgical secondary refinement process through two reduced-scale water experiments, which reproduce the dynamics seen in an industrial bottom-blown ladle. A container is filled with water and topped by a thin layer of oil, representing the molten steel and slag, respectively. The system is agitated by a bubble plume that impinges on the oil layer and forms an open-eye. A tracer species, dissolved in the water, acts as a passive scalar that is progressively absorbed into the oil layer. Both the hydrodynamics and mass transfer in the system are studied and compared with experiments from the literature of different size and geometry. - The numerical simulation of mass transfer is challenging due to the high P\'eclet number, leading to extremely thin species boundary layers at the interface. Resolving the boundary layer is prohibitive even with adaptive grid techniques. A subgrid-scale (SGS) boundary layer model corrects the scalar transport equation, allowing us to solve convection-dominated transport on relatively coarse grids. The hydrodynamics is investigated, and we analyze how the resultant flow field governs mass transport. The numerical results recover two flow regimes: a quasi-steady regime at low flow rates with small deformations of the oil-water interface and an atomizing regime at large flow rates. Interfacial species transport is determined to be dominated in an annulus surrounding the open eye caused by a shear layer at the oil-water interface. It is observed that we achieve grid-independent macroscopic quantities that match relatively well with those observed in experiments, allowing use of simulation techniques as a complementary tool going forward. - oai:arXiv.org:2509.05033v2 - physics.flu-dyn - Fri, 12 Dec 2025 00:00:00 -0500 - replace + Fri, 19 Dec 2025 00:00:00 -0500 + cross http://creativecommons.org/licenses/by/4.0/ - Stefano De Rosa, Jacob Maarek, St\'ephane Zaleski + Yilin Ye, Denis S. Grebenkov - An accurate mean-field equation for voter model dynamics on scale-free networks - https://arxiv.org/abs/2509.13485 - arXiv:2509.13485v3 Announce Type: replace -Abstract: Understanding the emergent macroscopic behavior of dynamical systems on networks is a crucial but challenging task. One of the simplest and most effective methods to construct a reduced macroscopic model is given by mean-field theory. The resulting approximations perform well on dense and homogeneous networks but poorly on scale-free networks, which, however, are more realistic in many applications. In this paper, we introduce a modified version of the mean-field approximation for voter model dynamics on scale-free networks. The two main deviations from classical theory are that we use degree-weighted shares as coarse variables and that we introduce a correlation factor that can be interpreted as slowing down dynamics induced by interactions. We observe that the correlation factor is only a property of the network and not of the state or of parameters of the process. This approach achieves a significantly smaller approximation error than standard methods without increasing dimensionality. - oai:arXiv.org:2509.13485v3 - physics.soc-ph - Fri, 12 Dec 2025 00:00:00 -0500 - replace - http://creativecommons.org/licenses/by-nc-nd/4.0/ - Marvin L\"ucke, Stefanie Winkelmann, P\'eter Koltai - - - Quantized topological transport mediated by the long-range couplings - https://arxiv.org/abs/2509.13553 - arXiv:2509.13553v2 Announce Type: replace -Abstract: Certain topological systems with time-varying Hamiltonian enable quantized and disorder-robust transport of excitations. Here, we introduce the modification of the celebrated Thouless pump when the on-site energies remain fixed, while the nearest and next-nearest neighbor couplings vary in time. We demonstrate quantized transport of excitations and propose an experimental implementation using an array of evanescently coupled optical waveguides. - oai:arXiv.org:2509.13553v2 - physics.optics - cond-mat.mes-hall - Fri, 12 Dec 2025 00:00:00 -0500 - replace + Structure of the mean-field yrast spectrum of a two-component Bose gas in a ring: role of interaction asymmetry + https://arxiv.org/abs/2512.16756 + arXiv:2512.16756v1 Announce Type: cross +Abstract: The mean-field yrast spectrum of an SU(2)-symmetric two-component Bose gas confined to a ring geometry is known to exhibit an intricate nonanalytic structure that is absent in single-component systems. In particular, due to the interplay between the species concentration and the atomic interactions, a sequence of plane-wave states can emerge as yrast states at fractional values of the angular momentum per particle. This behavior stands in sharp contrast to the single-component case, where plane-wave states occur only at integer angular momenta. In this paper, we investigate how the structure of the yrast spectrum in a two-component Bose gas is modified by interaction asymmetry. By numerically solving the coupled Gross-Pitaevskii equations for propagating soliton states, we compute the mean-field yrast spectrum and, in particular, determine the critical curves associated with the emergence of various plane-wave yrast states. We find that both the behavior of these critical curves and the mechanisms by which plane-wave yrast states arise depend sensitively on the relative strengths of the inter- and intra-component interactions. When the inter-component interaction is weaker, the plane-wave yrast states replace soliton states through a continuous evolution, as in the SU(2)-symmetric case, although the conditions for their existence become more restrictive. In contrast, when the inter-component interaction is stronger, plane-wave yrast states emerge by overtaking soliton states via branch crossings, and their stability is significantly enhanced. Our results have important implications for the existence and stability of persistent currents in asymmetric, two-component Bose gases. + oai:arXiv.org:2512.16756v1 + cond-mat.quant-gas + physics.atom-ph + Fri, 19 Dec 2025 00:00:00 -0500 + cross http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Ekaterina S. Lebedeva, Maxim Mazanov, Alexey V. Kavokin, Maxim A. Gorlach + Hui Tang, Guan-Hua Huang, Eugene Zaremba, Shizhong Zhang, Zhigang Wu - Meta-optical Miniscope for Multifunctional Imaging - https://arxiv.org/abs/2509.16373 - arXiv:2509.16373v2 Announce Type: replace -Abstract: Miniaturized microscopes (miniscopes) have opened a new frontier in animal behavior studies, enabling real-time imaging of neuron activity while leaving animals largely unconstrained. Canonical designs typically use Gradient-Index (GRIN) lenses or refractive lenses as the objective module for excitation and fluorescence collection, but GRIN lenses suffer from aberrations and refractive lenses are bulky and complex. Meta-optics, composed of subwavelength diffractive elements, offer a promising alternative by combining multiple functionalities with significantly reduced footprint and weight. Here, we present meta-optical miniscopes that integrate functionalities including large field of view (FOV), extended depth of focus (EDOF), and depth sensitivity. These meta-optics replace the traditional refractive lens assembly, reducing the total track length of the objective module from 6.7 mm to 2.5 mm while enhancing imaging performance. Our results demonstrate that meta-optical miniscopes can expand the miniscope toolbox and facilitate the development of more compact and multifunctional imaging systems. - oai:arXiv.org:2509.16373v2 - physics.optics - Fri, 12 Dec 2025 00:00:00 -0500 - replace + Efficient Monte-Carlo sampling of metastable systems using non-local collective variable updates + https://arxiv.org/abs/2512.16812 + arXiv:2512.16812v1 Announce Type: cross +Abstract: Monte-Carlo simulations are widely used to simulate complex molecular systems, but standard approaches suffer from metastability. Lately, the use of non-local proposal updates in a collective-variable (CV) space has been proposed in several works. Here, we generalize these approaches and explicitly spell out an algorithm for non-linear CVs and underdamped Langevin dynamics. We prove reversibility of the resulting scheme and demonstrate its performance on several numerical examples, observing a substantial performance increase compared to methods based on overdamped Langevin dynamics as considered previously. Advances in generative machine-learning-based proposal samplers now enable efficient sampling in CV spaces of intermediate dimensionality (tens to hundreds of variables), and our results extend their applicability toward more realistic molecular systems. + oai:arXiv.org:2512.16812v1 + cond-mat.stat-mech + physics.comp-ph + Fri, 19 Dec 2025 00:00:00 -0500 + cross http://creativecommons.org/licenses/by/4.0/ - Zhihao Zhou, Khushboo Kumari, Ningzhi Xie, Shane Colburn, Chetan Poudel, Praneeth Chakravarthula, Karl F. B\"ohringer, Arka Majumdar, Johannes E. Fr\"och + Christoph Sch\"onle, Davide Carbone, Marylou Gabri\'e, Tony Leli\`evre, Gabriel Stoltz - Tunable 300 W single-frequency 2 micron fiber amplifier - https://arxiv.org/abs/2510.05238 - arXiv:2510.05238v2 Announce Type: replace -Abstract: We present an all-fiber design for a Tm-based fiber amplifier that can tune over 1992-2065 nm with 300-350 W single-frequency (<100 kHz) output. Over 180 W is achieved out to 2085 nm with <10% ASE content without utilizing ASE spectral filters. The amplifier employs both Tm- and Tm/Ho-doped gain fibers in two preamplifier stages in addition to longer sections of Tm fiber to extend the bandwidth of the Tm-based high-power amplifier to longer wavelengths (>2050 nm). Efficiencies of 55% are realized across the full bandwidth. Roll-off occurs beyond 2085 nm where ASE becomes intractable. The amplifier has an average M^2 value of 1.39 at high-power due to the presence of light guided within the fiber pedestal. Estimates of the pedestal light and higher-order mode contents are provided. - oai:arXiv.org:2510.05238v2 - physics.optics - Fri, 12 Dec 2025 00:00:00 -0500 - replace + Thermodynamical study of N$_2$ clathrate hydrate from DFT calculations + https://arxiv.org/abs/2512.16819 + arXiv:2512.16819v1 Announce Type: cross +Abstract: Thermodynamic stability of N$_2$ clathrate hydrates in the sI and sII structures is investigated using density functional theory with several exchange-correlation functionals, explicitly accounting for composition (cage occupancies) and pressure at T = 0 K. Among the tested functionals, revPBE-D3(0) best reproduces experimental lattice parameters and bulk moduli B$_0$ . Energetic analyses confirm the strong impact of large cage double occupancy on sI, whereas the convex-hull results show that sI with single occupancy remains thermodynamically stable up to $\sim$ 0.8 GPa alongside sII with single occupancy. Increasing pressure then stabilizes sII with double occupancy, consistent with its larger large-cage volume and lower framework strain. These results provide a coherent, first-principles thermodynamic framework for N$_2$ hydrate stability and a baseline for finite-temperature extension. + oai:arXiv.org:2512.16819v1 + cond-mat.mtrl-sci + physics.comp-ph + Fri, 19 Dec 2025 00:00:00 -0500 + cross http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Reagan R. D. Weeks, Ryan A. Lane, Brian M. Anderson + L. Martin-Gondre, V. Meko Fotso, C. M\'etais, A. Patt, J. Ollivier, A. Desmedt - New GPU developments in the Madgraph CUDACPP plugin: kernel splitting, helicity streams, cuBLAS color sums - https://arxiv.org/abs/2510.05392 - arXiv:2510.05392v3 Announce Type: replace -Abstract: The first production release of the CUDACPP plugin for the Madgraph5_aMC@NLO generator, which speeds up matrix element (ME) calculations for leading-order (LO) processes using a data parallel approach on vector CPUs and GPUs, was delivered in October 2024. This was described in previous publications by the team behind that effort. In this paper, I describe my work on some additional developments and optimizations of CUDACPP, mainly but not exclusively for GPUs. The new approach, which represents a major restructuring of the CUDACPP computational engine, primarily consists in splitting the ME calculation, previously performed using a single large GPU kernel, into many smaller kernels. A first batch of changes, involving the move to separate "helicity streams" and the optional offloading of QCD color sums to BLAS, was recently merged into a new CUDACPP release, in collaboration with my colleagues. Since then, I have completed a second batch of changes, involving the possibility to split the calculation into groups of Feynman diagrams in separate source code files. This new feature makes it possible to compute QCD matrix elements for physics processes with a larger number of final state gluons: in particular, I present the first performance results from CUDACPP for the $2\!\rightarrow\!6$ process $gg\!\rightarrow\!t\bar{t}gggg$ on CPUs and GPUs and the $2\!\rightarrow\!7$ process $gg\!\rightarrow\!t\bar{t}ggggg$ on CPUs, which involve over 15k and 230k Feynman diagrams, respectively. I also take this opportunity to describe in detail some previously undocumented features of the CUDACPP software, both in the GPU and vector CPU implementations. - oai:arXiv.org:2510.05392v3 - physics.comp-ph - hep-ex - hep-ph - Fri, 12 Dec 2025 00:00:00 -0500 - replace - http://creativecommons.org/licenses/by/4.0/ - Andrea Valassi + Signatures of real-space geometry, topology, and metric tensor in quantum transport in periodically corrugated spaces + https://arxiv.org/abs/2512.16846 + arXiv:2512.16846v1 Announce Type: cross +Abstract: The motion of a quantum particle constrained to a two-dimensional non-compact Riemannian manifold with non-trivial metric can be described by a flat-space Schroedinger-type equation at the cost of introducing local mass and metric and geometry-induced effective potential with no classical counterpart. For a metric tensor periodically modulated along one dimension, the formation of bands is demonstrated and transport-related quantities are derived. Using S-matrix approach, the quantum conductance along the manifold is calculated and contrasted with conventional quantum transport methods in flat spaces. The topology, e.g. whether the manifold is simply connected, compact or non-compact shows up in global, non-local properties such as the Aharonov-Bohm phase. The results vividly demonstrate emergent phenomena due to the interplay of reduced-dimensionality, particles quantum nature, geometry, and topology. + oai:arXiv.org:2512.16846v1 + cond-mat.mes-hall + math-ph + math.MP + physics.class-ph + quant-ph + Fri, 19 Dec 2025 00:00:00 -0500 + cross + http://creativecommons.org/licenses/by-nc-sa/4.0/ + Benjamin Schwager, Theresa Appel, Jamal Berakdar - Enhancing NMR Shielding Predictions of Atoms-in-Molecules Machine Learning Models with Neighborhood-Informed Representations - https://arxiv.org/abs/2510.05623 - arXiv:2510.05623v3 Announce Type: replace -Abstract: Accurate prediction of nuclear magnetic resonance (NMR) shielding with machine learning (ML) models remains a central challenge for data-driven spectroscopy. We present atomic variants of the Coulomb matrix (aCM) and bag-of-bonds (aBoB) descriptors, and extend them using radial basis functions (RBFs) to yield smooth, per-atom representations (aCM-RBF, aBoB-RBF). Local structural information is incorporated by augmenting each atomic descriptor with contributions from the n nearest neighbors, resulting in the family of descriptors, aCM-RBF(n) and aBoB-RBF(n). For 13C shielding prediction on the QM9NMR dataset (831,925 shielding values across 130,831 molecules), aBoB-RBF(4) achieves an out-of-sample mean error of 1.69 ppm, outperforming models reported in previous studies. While explicit three-body descriptors further reduce errors at a higher cost, aBoB-RBF(4) offers the best balance of accuracy and efficiency. Benchmarking on external datasets comprising larger molecules (GDBm, Drug12/Drug40, and pyrimidinone derivatives) confirms the robustness and transferability of aBoB-RBF(4), establishing it as a practical tool for ML-based NMR shielding prediction. - oai:arXiv.org:2510.05623v3 - physics.chem-ph - Fri, 12 Dec 2025 00:00:00 -0500 - replace - http://creativecommons.org/licenses/by-nc-nd/4.0/ - Surajit Das, Raghunathan Ramakrishnan + Photonics of topological magnetic textures + https://arxiv.org/abs/2512.16870 + arXiv:2512.16870v1 Announce Type: cross +Abstract: Topological textures in magnetically ordered materials are important case studies for fundamental research with promising applications in data science. They can also serve as photonic elements to mold electromagnetic fields endowing them with features inherent to the spin order, as demonstrated analytically and numerically in this work. A self-consistent theory is developed for the interaction of spatially structured electromagnetic fields with non-collinear, topologically non-trivial spin textures. A tractable numerical method is designed and implemented for the calculation of the formed magnetic/photonic textures in the entire simulation space. Numerical illustrations are presented for scattering from point-like singularities, i.e. Bloch points, in the magnetization vector fields, evidencing that the geometry and topology of the magnetic order results in photonic fields that embody orbital angular momentum, chirality as well as magnetoelectric densities. Features of the scattered fields can serve as a fingerprint for the underlying magnetic texture and its dynamics. The findings point to the potential of topological magnetic textures as a route to molding photonic fields. + oai:arXiv.org:2512.16870v1 + cond-mat.other + physics.app-ph + physics.optics + Fri, 19 Dec 2025 00:00:00 -0500 + cross + http://creativecommons.org/licenses/by-nc-sa/4.0/ + Vakhtang Jandieri, Ramaz Khomeriki, Daniel Erni, Nicolas Tsagareli, Qian Li, Douglas H. Werner, Jamal Berakdar - The BUTTON-30 detector at Boulby - https://arxiv.org/abs/2510.13173 - arXiv:2510.13173v2 Announce Type: replace -Abstract: The BUTTON-30 detector is a 30-tonne technology demonstrator designed to evaluate the potential of hybrid event detection, simultaneously exploiting both Cherenkov and scintillation light to detect particle produced in neutrino interactions. The detector is installed at a depth of 1.1 km in the Boulby Underground Laboratory allowing to test the performance of this new technology underground in a low background environment. This paper describes the design and construction of the experiment. - oai:arXiv.org:2510.13173v2 - physics.ins-det - hep-ex - nucl-ex - Fri, 12 Dec 2025 00:00:00 -0500 + Effect of inertial lift on a spherical particle suspended in flow through a curved duct + https://arxiv.org/abs/1902.06848 + arXiv:1902.06848v2 Announce Type: replace +Abstract: We develop a model of the forces on a spherical particle suspended in flow through a curved duct under the assumption that the particle Reynolds number is small. This extends an asymptotic model of inertial lift force previously developed to study inertial migration in straight ducts. Of particular interest is the existence and location of stable equilibria within the cross-sectional plane towards which particles migrates. The Navier-Stokes equations determine the hydrodynamic forces acting on a particle. A leading order model of the forces within the cross-sectional plane is obtained through the use of a rotating coordinate system and a perturbation expansion in the particle Reynolds number of the disturbance flow. We predict the behaviour of neutrally buoyant particles at low flow rates and examine the variation in focusing position with respect to particle size and bend radius, independent of the flow rate. In this regime, the lateral focusing position of particles approximately collapses with respect to a dimensionless parameter dependent on three length scales, specifically the particle radius, duct height, and duct bend radius. Additionally, a trapezoidal shaped cross-section is considered in order to demonstrate how changes in the cross-section design influence the dynamics of particles. + oai:arXiv.org:1902.06848v2 + physics.flu-dyn + Fri, 19 Dec 2025 00:00:00 -0500 replace - http://creativecommons.org/licenses/by/4.0/ - J. Bae, M. Bergevin, E. P. Bernard, D. S. Bhattacharya, J. Boissevain, S. Boyd, K. Bridges, L. Capponi, J. Coleman, D. Costanzo, T. Cunniffe, S. A. Dazeley, M. V. Diwan, S. R. Durham, E. Ellingwood, A. Enqvist, T. Gamble, S. Gokhale, J. Gooding, C. Graham, E. Gunger, J. J. Hecla, W. Hopkins, I. Jovanovic, T. Kaptanoglu, E. Kneale, L. Lebanowski, K. Lester, V. A. Li, M. Malek, C. Mauger, N. McCauley, C. Metelko, R. Mills, A. Morgan, F. Muheim, A. Murphy, M. Needham, K. Ogren, G. D. Orebi Gann, S. M. Paling, A. F. Papatyi, A. Petts, G. Pinkney, J. Puputti, S. Quillin, B. Richards, R. Rosero, A. Scarff, Y. Schnellbach, P. R. Scovell, B. Seitz, L. Sexton, O. Shea, G. D. Smith, R. Svoboda, D. Swinnock, A. Tarrant, F. Thomson, J. N. Tinsley, C. Toth, M. Vagins, G. Yang, M. Yeh, E. Zhemchugov + http://arxiv.org/licenses/nonexclusive-distrib/1.0/ + 10.1017/jfm.2019.323 + Harding, B., Stokes, Y.M. and Bertozzi, A.L. (2019) Effect of inertial lift on a spherical particle suspended in flow through a curved duct, Journal of Fluid Mechanics, 875, pp. 1-43 + B. Harding, Y. M. Stokes, A. L. Bertozzi - Non-Resonant Raman Optical Activity From Phase-Space Electronic Structure Theory - https://arxiv.org/abs/2510.18746 - arXiv:2510.18746v2 Announce Type: replace -Abstract: In order to model experimental non-resonant Raman optical activity, chemists must compute a host of second-order response tensors, (e.g. the electric-dipole magnetic-dipole polarizability) and their nuclear derivatives along a set of vibrational modes. While these response functions are almost always computed within a Born-Oppenheimer (BO) framework, here we provide a natural interpretation of the electric-dipole magnetic-dipole polarizability within phase space electronic structure theory, a beyond-BO model whereby the electronic structure depends on nuclear momentum (P) in addition to nuclear position (R). By coupling to nuclear momentum, phase space electronic structure theory is able to capture the asymmetric response of the electronic properties to an external field, in sofar as for a vibrating (non-stationary) molecule, dmu/dB \ne dm/dF, where mu and m are the electrical linear and magnetic dipoles, and F and B are electric and magnetic fields. As an example, for a prototypical methyloxirane molecule, we show that phase space electronic structure theory is able to deliver a reasonably good match with experimental results in a manner that is invariant to gauge origin G0. - oai:arXiv.org:2510.18746v2 - physics.chem-ph - Fri, 12 Dec 2025 00:00:00 -0500 + Conceptual study on using Doppler backscattering to measure magnetic pitch angle in tokamak plasmas + https://arxiv.org/abs/2502.19061 + arXiv:2502.19061v2 Announce Type: replace +Abstract: We introduce a new approach to measure the magnetic pitch angle profile in tokamak plasmas with Doppler backscattering (DBS), a technique traditionally used for measuring flows and density fluctuations. The DBS signal is maximised when its probe beam's wavevector is perpendicular to the magnetic field at the cutoff location, independent of the density fluctuations. Hence, if one could isolate this effect, DBS would then yield information about the magnetic pitch angle. By varying the toroidal launch angle, the DBS beam reaches cutoff with different angles with respect to the magnetic field, but with other properties remaining similar. Hence, the toroidal launch angle which gives maximum backscattered power is thus that which is matched to the pitch angle at the cutoff location, enabling inference of the magnetic pitch angle. We performed systematic scans of the DBS toroidal launch angle for repeated DIII-D tokamak discharges. Experimental DBS data from this scan were analysed and combined with Gaussian beam-tracing simulations using the Scotty code. The pitch-angle inferred from DBS is consistent with that from magnetics-only and motional-Stark-effect-constrained (MSE) equilibrium reconstruction in the edge. In the core, the pitch angles from DBS and magnetics-only reconstructions differ by one to two degrees, while simultaneous MSE measurements were not available. The uncertainty in these measurements was under a degree; we show that this uncertainty is primarily due to the error in toroidal steering, the number of toroidally separated measurements, and shot-to-shot repeatability. We find that the error of pitch-angle measurements can be reduced by optimising the poloidal launch angle and initial beam properties. + oai:arXiv.org:2502.19061v2 + physics.plasm-ph + Fri, 19 Dec 2025 00:00:00 -0500 replace http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Zhen Tao, Mansi Bhati, Joseph E. Subotnik + AK Yeoh, VH Hall-Chen, QT Pratt, BS Victor, J Damba, TL Rhodes, NA Crocker, KR Fong, JC Hillesheim, FI Parra, J Ruiz Ruiz - Many-Body Floquet Theory for Radiative Heat Transfer in Time-Modulated Systems - https://arxiv.org/abs/2510.19378 - arXiv:2510.19378v4 Announce Type: replace -Abstract: We develop a general theory of radiative heat exchange between dipoles with time-modulated optical properties. This framework extends fluctuational electrodynamics beyond equilibrium by incorporating nonstationary correlations and memory effects induced by temporal modulation. Closed-form expressions for the heat currents in modulated many-body systems are obtained, together with a generalized Landauer-like formulation of the pairwise exchanges, where the transmission coefficient accounts for all inelastic frequency-conversion channels. Near-resonant modulation redistributes and amplifies thermal fluctuations across Floquet sidebands, acting as a parametric amplifier of thermal radiation and enabling active, frequency-selective control of nanoscale heat transfer. - oai:arXiv.org:2510.19378v4 - physics.optics - cond-mat.mes-hall - Fri, 12 Dec 2025 00:00:00 -0500 + Cell divisions both challenge and refine tissue boundaries in the Drosophila embryo + https://arxiv.org/abs/2503.24261 + arXiv:2503.24261v2 Announce Type: replace +Abstract: Tissue boundaries pattern embryos, suppress tumours, and provide directional cues. Tissue boundaries are associated with supracellular cables formed by actin and the molecular motor non-muscle myosin II. Actomyosin cables generate tension that prevents cell mixing. Whether other cellular behaviours contribute to the formation of linear interfaces between cell populations remains unclear. In the Drosophila embryo, an actomyosin-based boundary separates the ectoderm from the mesectoderm, a group of neuronal and glial progenitors. Mathematical modelling predicted that cell divisions in the ectoderm challenge the mesectoderm-ectoderm (ME) boundary. Consistent with this, suppressing ectoderm cell divisions in vivo prevented cell mixing across the ME boundary when actomyosin-based tension was lost. Our mathematical model also predicted that cell divisions sharpen the ME boundary by reducing tension and increasing cell motility in the ectoderm. We found that inhibiting ectoderm divisions in vivo reduced boundary linearity. Using laser ablation and cell tracking, we demonstrated that cell divisions reduced junctional tension and increased cell movement in the ectoderm. Together, our results reveal that cell divisions facilitate cellular rearrangements to increase fluidity in a novel mechanism for boundary refinement. + oai:arXiv.org:2503.24261v2 + physics.bio-ph + Fri, 19 Dec 2025 00:00:00 -0500 replace - http://creativecommons.org/licenses/by/4.0/ - Riccardo Messina, Philippe Ben-Abdallah + http://creativecommons.org/licenses/by-nc-nd/4.0/ + Veronica Castle, Merdeka Miles, Rafael Perez-Vicente, Rodrigo Fernandez-Gonzalez, Gonca Erdemci-Tandogan - General properties of the RABBITT at parity mixing conditions - https://arxiv.org/abs/2511.04284 - arXiv:2511.04284v2 Announce Type: replace -Abstract: Parity mixing in photoionization, i.e. when emitted electrons have different parities but the same energy, causes interference observable only in angle-resolved measurements. The interference typically manifests as a symmetry violation in the photoelectron angular distributions. The traditional, based on HHG, RABBITT scheme with high-order harmonics separated by twice the seed field energy, precludes parity mixing. On the contrary, a free-electron laser provides a possibility to generate even harmonics. Using triple the fundamental frequency as a seed, one obtains a comb of alternating even and odd harmonics, separated by three times the initial frequency [Nature 578, 386-391 (2020)] (2-SB RABBITT). In this setup, there are two sidebands between the main photoelectron lines, versus one in the traditional scheme. In the paper, we examine the general properties of a two-sideband scheme and analyze the symmetry breakdown of photoelectron angular distributions for various polarization geometries of the incident pulse. We found a crucial difference in symmetries between 2-SB RABBITT and other photoionization schemes with parity mixing. Illustrative calculations are carried out for neon with pulse parameters typical for modern facilities. The possibility to reconstruct the temporal profile of the pulse from the angle-resolved measurements is discussed. - oai:arXiv.org:2511.04284v2 - physics.atom-ph - Fri, 12 Dec 2025 00:00:00 -0500 + Rapid general Electromagnetic Analysis with computational conformal geometry via Conformal Energy Minimization + https://arxiv.org/abs/2505.17227 + arXiv:2505.17227v2 Announce Type: replace +Abstract: We recently found that the electromagnetic scattering problem can be very fast in an approach expressing the fields in terms of orthonormal basis functions. In this paper we apply computational conformal geometry with the conformal energy minimization (CEM) algorithm to make possible fast solution of finite-frequency electromagnetic problems involving arbitrarily shaped, simply-connected metallic surfaces. The CEM algorithm computes conformal maps with minimal angular distortion, enabling the transformation of arbitrary simply-connected surfaces into a disk, where orthogonal basis functions can be defined and electromagnetic analysis can be significantly simplified. We demonstrate the effectiveness and efficiency of our method by investigating the resonance characteristics of two metallic surfaces: a square plate and a four-petal plate. Compared to traditional finite element methods (e.g., COMSOL), our approach achieves a three-order-of-magnitude improvement in computational efficiency, requiring only seconds to extract resonant frequencies and fields. Moreover, it reveals low-energy, doubly degenerate resonance modes that are elusive to conventional methods. These findings not only provide a powerful tool for analyzing electromagnetic fields on complex geometries but also pave the way for the design of high-performance electromagnetic devices. + oai:arXiv.org:2505.17227v2 + physics.optics + Fri, 19 Dec 2025 00:00:00 -0500 replace http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Maria M. Popova, Sergei N. Yudin, Alexei N. Grum-Grzhimailo, Elena V. Gryzlova + Pengcheng Wan, Zhong-Heng Tan, S. T. Chui, Tiexiang Li, S. T. Yau - Response of a magnetically diverted tokamak plasma to a resonant magnetic perturbation - https://arxiv.org/abs/2511.07666 - arXiv:2511.07666v2 Announce Type: replace -Abstract: The safety-factor profile of a magnetically diverted tokamak plasma diverges logarithmically as the magnetic separatrix (a.k.a. the last closed magnetic flux-surface) is approached. At first sight, this suggests that, when determining the response of such a plasma to a static, externally generated, resonant magnetic perturbation (RMP), it is necessary to include an infinite number of rational magnetic flux-surfaces in the calculation, the majority of which lie very close to the separatrix. In fact, when finite plasma resistivity is taken into account, this turns out not to be the case. Instead, it is only necessary to include rational surfaces that lie in the region 0<Psi<Psi_c, where Psi is the normalized poloidal magnetic flux, and Psi_c<1 can be calculated from the edge plasma parameters. It is estimated that Psi_c= 0.9985 for an n=1 RMP, and Psi_c=0.9952 for an n=4 RMP, in a typical JET H-mode plasma. - oai:arXiv.org:2511.07666v2 - physics.plasm-ph - Fri, 12 Dec 2025 00:00:00 -0500 + High-precision Beam Optics Calculation of the HIAF-BRing Using Measured Fields + https://arxiv.org/abs/2506.08421 + arXiv:2506.08421v4 Announce Type: replace +Abstract: The construction of the High Intensity heavy ion Accelerator Facility (HIAF) has been completed, with current efforts focused on subsystem commissioning. Beam commissioning is scheduled for autumn 2025, marking a critical milestone in the HIAF project. This paper presents high-precision optics calculations for the Booster Ring (BRing) of HIAF, a key component for achieving stable heavy-ion beam acceleration. Leveraging high-precision magnetic field data, each magnet is divided into hundreds of slices, thus establishing a high-precision sliced optics model for BRing. Detailed calculations of BRing's optics are presented in this work. Critical parameters including tunes and betatron functions of the lattice based on the measured magnetic fields and those of the ideal lattice have been compared. The results highlight the impact of realistic magnetic field on beam dynamics and provide essential insights for accelerator tuning and optimization. These findings serve as a fundamental reference for beam commissioning and long-term operation, ensuring beam stability and performance reproducibility in HIAF. + oai:arXiv.org:2506.08421v4 + physics.acc-ph + Fri, 19 Dec 2025 00:00:00 -0500 replace - http://creativecommons.org/licenses/by-nc-nd/4.0/ - R. Fitzpatrick + http://arxiv.org/licenses/nonexclusive-distrib/1.0/ + 10.1088/1748-0221/20/08/P08023 + Journal of Instrumentation, Volume 20, August 2025 + Ke Wang, Li-Na Sheng, Geng Wang, Wei-Ping Chai, You-Jin Yuan, Jian-Cheng Yang, Guo-Dong Shen, Liang Lu - Progress on the ALETHEIA project and a new approach to mitigate events overlap - https://arxiv.org/abs/2511.08954 - arXiv:2511.08954v2 Announce Type: replace -Abstract: The ALETHEIA project aims to search for low-mass dark matter using liquid helium (LHe)-filled time projection chambers (TPCs). While liquid argon and liquid xenon TPCs have been extensively employed in the field of direct dark matter detection, successful development of LHe TPCs has not yet been achieved. Launched in 2020, our project has made significant progress since then. These advancements have convinced us that a single-phase LHe TPC is technologically feasible. Compared to liquid xenon and liquid argon TPCs, one of the unique challenges for LHe TPCs is event overlap caused by the 13-second lifetime scintillation. We will demonstrate that this overlap can be entirely mitigated when the LHe temperature is maintained near 1.0 K. At this temperature, electron mobility is three orders of magnitude higher than at approximately 4.0 K, which is the temperature we initially proposed for the LHe TPC. - oai:arXiv.org:2511.08954v2 - physics.ins-det - astro-ph.IM - Fri, 12 Dec 2025 00:00:00 -0500 + Beyond Force Metrics: Pre-Training MLFFs for Stable MD Simulations + https://arxiv.org/abs/2506.14850 + arXiv:2506.14850v2 Announce Type: replace +Abstract: Machine-learning force fields (MLFFs) have emerged as a promising solution for speeding up ab initio molecular dynamics (MD) simulations, where accurate force predictions are critical but often computationally expensive. In this work, we employ GemNet-T, a graph neural network model, as an MLFF and investigate two training strategies: (1) direct training on MD17 (10K samples) without pre-training, and (2) pre-training on the large-scale OC20 dataset followed by fine-tuning on MD17 (10K). While both approaches achieve low force mean absolute errors (MAEs), reaching 5 meV/A per atom, we find that lower force errors do not necessarily guarantee stable MD simulations. Notably, the pre-trained GemNet-T model yields significantly improved simulation stability, sustaining trajectories up to three times longer than the model trained from scratch. By analyzing local properties of the learned force fields, we find that pre-training produces more structured latent representations, smoother force responses to local geometric changes, and more consistent force differences between nearby configurations, all of which contribute to more stable and reliable MD simulations. These findings underscore the value of pre-training on large, diverse datasets to capture complex molecular interactions and highlight that force MAE alone is not always a sufficient metric of MD simulation stability. + oai:arXiv.org:2506.14850v2 + physics.chem-ph + cs.LG + Fri, 19 Dec 2025 00:00:00 -0500 replace - http://creativecommons.org/licenses/by-nc-nd/4.0/ - Junhui Liao (on behalf of the ALETHEIA collaboration) + http://creativecommons.org/licenses/by/4.0/ + Shagun Maheshwari, Janghoon Ock, Adeesh Kolluru, Amir Barati Farimani, John R. Kitchin - Uncovering bistability phenomena in two-layer Couette flow experiments using nonlocal evolution equations - https://arxiv.org/abs/2511.20880 - arXiv:2511.20880v2 Announce Type: replace -Abstract: This paper investigates the stability of interfacial long waves in two-layer plane Couette flow using a nonlinear, nonlocal asymptotic model derived from the Navier-Stokes equations and valid for thin upper layers. Nonlocality enters through a coupling of the thin and main layers, and crucial inertial effects are retained. The models generically support bistability phenomena observed in experiments where two stable travelling waves, one unimodal and the other bimodal, are recorded at the same lid velocity. In direct comparisons with experiments the models show remarkable agreement, both qualitatively and quantitatively. The two stable travelling waves are identified and their basins of attraction characterised via large-time computations for different initial conditions. - oai:arXiv.org:2511.20880v2 - physics.flu-dyn - Fri, 12 Dec 2025 00:00:00 -0500 + Quantifying Resolution Limits in Pedestal Profile Measurements with Gaussian Process Regression + https://arxiv.org/abs/2507.05067 + arXiv:2507.05067v2 Announce Type: replace +Abstract: Edge transport barriers (ETBs) in magnetically confined fusion plasmas, commonly known as pedestals, play a crucial role in achieving high confinement plasmas. However, their defining characteristic, a steep rise in plasma pressure over short length scales, makes them challenging to diagnose experimentally. In this work, we use Gaussian Process Regression (GPR) to develop first-principles metrics for quantifying the spatiotemporal resolution limits of inferring differentiable profiles of temperature, pressure, or other quantities from experimental measurements. Although we focus on pedestals, the methods are fully general and can be applied to any setting involving the inference of profiles from discrete measurements. First, we establish a correspondence between GPR and low-pass filtering, giving an explicit expression for the effective `cutoff frequency' associated with smoothing incurred by GPR. Second, we introduce a novel information-theoretic metric, \(N_{eff}\), which measures the effective number of data points contributing to the inferred value of a profile or its derivative. These metrics enable a quantitative assessment of the trade-off between `over-fitting' and `over-regularization', providing both practitioners and consumers of GPR with a systematic way to evaluate the credibility of inferred profiles. We apply these tools to develop practical advice for using GPR in both time-independent and time-dependent settings, and demonstrate their usage on inferring pedestal profiles using measurements from the DIII-D tokamak. + oai:arXiv.org:2507.05067v2 + physics.plasm-ph + Fri, 19 Dec 2025 00:00:00 -0500 replace http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Xingyu Wang, Pierre Germain, Demetrios T. Papageorgiou + 10.1088/1741-4326/ae2d6f + Norman M. Cao, David R. Hatch, Craig Michoski, Todd A. Oliver, David Eldon, Andrew Oakleigh Nelson, Matthew Waller - Fly-by transit: A novel door-to-door shared mobility with minimal stops - https://arxiv.org/abs/2511.21295 - arXiv:2511.21295v3 Announce Type: replace -Abstract: This paper introduces fly-by transit (FBT), a novel mobility system that employs modular mini-electric vehicles (mini-EVs) to provide door-to-door shared mobility with minimal stops. Unlike existing modular minibus concepts that rely on in-motion coupling and passenger transfers -- technologies unlikely to mature soon -- FBT lowers the technological barriers by building upon near-term feasible solutions. The system comprises two complementary mini-EV modules: low-cost trailers for on-demand feeder trips and high-performance leaders that guide coupled trailers in high-speed platoons along trunk lines. Trailers operate independently for detour-free feeder services, while stationary coupling at designated hubs enables platoons to achieve economies of scale (EoS). In-motion decoupling of the tail trailer allows stop-less operation without delaying the main convoy. - As a proof of concept, a stylized corridor model is developed to analyze optimal FBT design. Results indicate that FBT can substantially reduce travel times relative to conventional buses and lower operating costs compared with e-hailing taxis. Numerical analyses further demonstrate that FBT achieves stronger EoS than both buses and taxis, yielding more than 13\% savings in generalized system costs. By addressing key limitations of existing transit systems, this study establishes FBT as a practical and scalable pathway toward transformative urban mobility and outlines directions for future research. - oai:arXiv.org:2511.21295v3 + Model of dark current in silicon-based barrier impurity band infrared detector devices + https://arxiv.org/abs/2507.14923 + arXiv:2507.14923v3 Announce Type: replace +Abstract: Dark current in silicon-based blocked impurity band (BIB) infrared detectors has long been a critical limitation on device performance. This work proposes a chiral-phonon-assisted spin current model at interfaces to explain the parabolic-like dark current behavior observed at low bias voltages. Concurrently, the spatially-confined charge transport theory is employed to elucidate the dark current generation mechanism across the entire operational voltage range. + oai:arXiv.org:2507.14923v3 physics.app-ph - Fri, 12 Dec 2025 00:00:00 -0500 + cond-mat.str-el + Fri, 19 Dec 2025 00:00:00 -0500 replace http://creativecommons.org/licenses/by/4.0/ - Wenbo Fan, Weihua Gu + Mengyang Cui + + + Three-dimensional numerical study on hydrogen bubble growth at electrode + https://arxiv.org/abs/2507.15582 + arXiv:2507.15582v4 Announce Type: replace +Abstract: Three-dimensional direct numerical simulation of electrolysis is applied to investigate the growth and detachment of bubbles at electrodes. + The moving gas-liquid interface is modeled employing the VOF-based method. To ensure the accuracy of the simulations, + a mesh-independence study has been performed. + The simulations include the growth phase of the bubbles, followed by their detachment from the electrode surface, + and the results are validated with analytical models and experimental data. + The bubble growth is diffusion-controlled, leading to the scaling \(R\propto t^{1/2}\), but our simulation overpredicts the growth exponent during the initial stage. + We further demonstrate that the number of nucleation sites significantly affects gas transport, as quantified by the Sherwood number. + The influences of contact angle and nucleation site on bubble detachment are also examined. + The predicted detachment radius varies linearly with contact angle, consistent with Fritz's linear relation + between the volume-equivalent radius and contact angle, confirming that the surface tension is the dominant attachment force. + Finally, as the nucleation sites increase, the induced bubble coalescence accelerates the bubble detachment. Taken together, + these findings give us valuable insights into improving gas bubble removal and enhancing overall electrolysis efficiency. + oai:arXiv.org:2507.15582v4 + physics.flu-dyn + Fri, 19 Dec 2025 00:00:00 -0500 + replace + http://creativecommons.org/licenses/by-sa/4.0/ + Wei Qin, Tian Long, Jacob Maarek, St\'ephane Zaleski - Efficient Quantum Simulation of Non-Adiabatic Molecular Dynamics with Precise Electronic Structure - https://arxiv.org/abs/2512.02376 - arXiv:2512.02376v2 Announce Type: replace -Abstract: In the study of non-adiabatic chemical processes such as photocatalysis and photosynthesis, non-adiabatic molecular dynamics (NAMD) is an indispensable theoretical tool, which requires precise potential energy surfaces (PESs) of ground and excited states. Quantum computing offers promising potential for calculating PESs that are intractable for classical computers. However, its realistic application poses significant challenges to the development of quantum algorithms that are sufficiently general to enable efficient and precise PES calculations across chemical systems with diverse properties, as well as to seamlessly adapt existing NAMD theories to quantum computing. In this work, we introduce a quantum-adapted extension to the Landau-Zener-Surface-Hopping (LZSH) NAMD. This extension incorporates curvature-driven hopping corrections that protect the population evolution while maintaining the efficiency gained from avoiding the computation of non-adiabatic couplings (NACs), as well as preserving the trajectory independence that enables parallelization. Furthermore, to ensure the high-precision PESs required for surface hopping dynamics, we develop a sub-microhartree-accurate PES calculation protocol. This protocol supports active space selection, enables parallel acceleration either on quantum or classical clusters, and demonstrates adaptability to diverse chemical systems - including the charged H3+ ion and the C2H4 molecule, a prototypical multi-reference benchmark. This work paves the way for practical application of quantum computing in NAMD, showcasing the potential of parallel simulation on quantum-classical heterogeneous clusters for ab-initio computational chemistry. - oai:arXiv.org:2512.02376v2 - physics.chem-ph - quant-ph - Fri, 12 Dec 2025 00:00:00 -0500 + Coherent phonon control beyond amplitude saturation in a sliding ferroelectric + https://arxiv.org/abs/2508.16422 + arXiv:2508.16422v2 Announce Type: replace +Abstract: The breakdown of Hooke's law marks the onset of nonlinear behaviour: when displacements become large, restoring forces weaken and conventional proportionality fails. In quantum materials, intense optical excitation can drive the crystal lattice into a similar regime, where established linear relations between light, electrons, and phonons no longer hold. Sliding ferroelectrics are particularly susceptible, as controlling their polarization requires large interlayer shifts. Displacive excitation of coherent phonons, the principal mechanism for launching structural motion, typically assumes that lattice-driving forces scale linearly with the photo-excited carrier density. Whether this linearity survives at high excitation, however, remains largely unexplored, and its breakdown can fundamentally limit accessible lattice displacements. Here we show that such nonlinear limitations can be surpassed in a sliding ferroelectric by timing, rather than strengthening the optical drive. Time-resolved second-harmonic generation reveals that the interlayer sliding phonon governing ferroelectricity saturates and even diminishes under single-pulse excitation. First-principles calculations attribute this nonlinearity to band-specific electron-phonon coupling that induces competing forces on the lattice. By splitting the optical energy into two well-timed pulses that avoid populating counteracting states, we achieve markedly larger phonon amplitudes at fixed total fluence. The resulting enhanced sliding motion exposes a regime of anharmonic phonon coupling that emerges only far from equilibrium. Our findings show that nonlinear limits in driven solids can be overcome, opening new pathways for steering lattice motion in quantum materials. + oai:arXiv.org:2508.16422v2 + physics.optics + Fri, 19 Dec 2025 00:00:00 -0500 replace - http://creativecommons.org/licenses/by-nc-nd/4.0/ - Tianyi Li, Yumeng Zeng, Qiming Ding, Zixuan Huo, Xiaosi Xu, Jiajun Ren, Diandong Tang, Xiaoxia Cai, Xiao Yuan + http://creativecommons.org/licenses/by/4.0/ + Jan Gerrit Horstmann, Christoph Emeis, Andrin Caviezel, Quintin N. Meier, Nicolas Wyler, Thomas Lottermoser, Fabio Caruso, Manfred Fiebig - Questions related to the Deflection of Light by Gravity determined by Soldner, Einstein and Schwarzschild - https://arxiv.org/abs/2512.04128 - arXiv:2512.04128v2 Announce Type: replace -Abstract: Before we discuss the deflection of light in a gravitational field, we give a brief overview of some basic physical formulas on photon properties, generation and propagation. The much debated problems of the redshift and the photon propagation in a gravitational field is then considered and applied to the calculation of the speed of light. Many citations are given in direct quotations to avoid any misunderstandings. If the quotations are in German, an English translation is provided. Based on this speed, calculated and measured results are recalled on the deflection of light, with emphasis on the deflection near the Sun. We conclude that the speed of light and the deflection angle can be determined by energy and momentum conservation principles. - oai:arXiv.org:2512.04128v2 - physics.hist-ph - astro-ph.SR - gr-qc - Fri, 12 Dec 2025 00:00:00 -0500 + Root Cause Analysis of Radiation Oncology Incidents Using Large Language Models + https://arxiv.org/abs/2508.17201 + arXiv:2508.17201v2 Announce Type: replace +Abstract: Purpose To evaluate the reasoning capabilities of large language models (LLMs) in performing root cause analysis (RCA) of radiation oncology incidents using narrative reports from the Radiation Oncology Incident Learning System (RO-ILS), and to assess their potential utility in supporting patient safety efforts. + Methods and Materials Four LLMs, Gemini 2.5 Pro, GPT-4o, o3, and Grok 3, were prompted with the 'Background and Incident Overview' sections of 19 public RO-ILS cases. Using a standardized prompt based on AAPM RCA guidelines, each model was instructed to identify root causes, lessons learned, and suggested actions. Outputs were assessed using semantic similarity metrics (cosine similarity via Sentence Transformers), semi-subjective evaluations (precision, recall, F1-score, accuracy, hallucination rate, and four performance criteria: relevance, comprehensiveness, justification, and solution quality), and subjective expert ratings (reasoning quality and overall performance) from five board-certified medical physicists. + Results LLMs showed promising performance. GPT-4o had the highest cosine similarity (0.831), while Gemini 2.5 Pro had the highest recall (0.799) and accuracy (0.918). Hallucination rates ranged from 11% to 61%. Gemini 2.5 Pro outperformed others across performance criteria and received the highest expert rating (4.8/5). Statistically significant differences in accuracy, hallucination, and subjective scores were observed (p < 0.05). + Conclusion LLMs show emerging promise as tools for RCA in radiation oncology. They can generate relevant, accurate analyses aligned with expert judgment and may support incident analysis and quality improvement efforts to enhance patient safety in clinical practice. + oai:arXiv.org:2508.17201v2 + physics.med-ph + Fri, 19 Dec 2025 00:00:00 -0500 replace - http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Klaus Wilhelm, Bhola N. Dwivedi, Karsten Muller + http://creativecommons.org/licenses/by-nc-sa/4.0/ + Yuntao Wang, Mariluz De Ornelas, Matthew T. Studenski, Elizabeth Bossart, Siamak P. Najad-Davarani, Yunze Yang - Design and Performance Simulation of the Electromagnetic Calorimeter at EicC - https://arxiv.org/abs/2512.04432 - arXiv:2512.04432v2 Announce Type: replace -Abstract: The electromagnetic calorimeter (ECAL) is a key detector component for precise electron and photon measurements in electron-ion collision experiments. At the Electron-Ion Collider in China (EicC), high-performance calorimetry is essential for exploring the internal structure of nucleons and studying the dynamics of quarks and gluons within quantum chromodynamics (QCD). This paper presents the optimized design and performance simulation of the EicC ECAL system. The ECAL consists of three specialized sections tailored to distinct detection environments: (1) an electron-Endcap employing high-resolution pure Cesium Iodide (pCsI) crystals, (2) a central barrel, and (3) an ion-Endcap, both adopting a cost-effective Shashlik-style sampling calorimeter with improved light yield. Each segment's geometry and material composition have been systematically optimized through Geant4 simulations to achieve excellent energy and position resolutions as well as strong electron-pion discrimination. The simulated performance indicates that the ECAL can achieve energy resolutions of 2 percent divided by sqrt(E) for pCsI crystals and 5 percent divided by sqrt(E) for Shashlik modules, meeting the design goals of the EicC detector. - oai:arXiv.org:2512.04432v2 + Toward precision physics tests with future COHERENT detectors + https://arxiv.org/abs/2509.04205 + arXiv:2509.04205v2 Announce Type: replace +Abstract: We present a comprehensive sensitivity study of future CE$\nu$NS detectors, focusing on a cryogenic cesium iodide detector and a tonne-scale liquid argon one, currently being developed by the COHERENT Collaboration. These setups will enable precision measurements of the weak mixing angle at low energies and allow accurate extraction of the neutron nuclear distribution radius. We also demonstrate that next-generation detectors will place constraints on the neutrino charge radius comparable to or better than current global fits. In addition, we explore the sensitivity to non standard neutrino electromagnetic properties, such as magnetic moments and millicharges, as well as new mediators. These findings reinforce the role of CE$\nu$NS experiments in the upcoming precision era, with future detectors playing a key role in advancing our understanding of neutrino interactions and electroweak physics at low energies. + oai:arXiv.org:2509.04205v2 physics.ins-det hep-ex - Fri, 12 Dec 2025 00:00:00 -0500 + hep-ph + Fri, 19 Dec 2025 00:00:00 -0500 replace - http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Ye Tian, Souvik Maity, Jingyu Li, Yuancai Wu, Shan Sha, Yutie Liang, Aiqiang Guo, Yuxiang Zhao, Dexu Lin + http://creativecommons.org/licenses/by/4.0/ + 10.3390/universe11120416 + Universe 2025, 11(12), 416 + M. Atzori Corona, M. Cadeddu, N. Cargioli, F. Dordei, C. Giunti, R. Pavarani - Natural Convection Heat Transfer from an Inclined Cylinder - https://arxiv.org/abs/2512.06019 - arXiv:2512.06019v2 Announce Type: replace -Abstract: This investigation derives a novel formula predicting the natural convective heat transfer from an inclined cylinder given its length, diameter, inclination angle, Rayleigh number, and the fluid's Prandtl number and thermal conductivity. - The present formula was tested with 93 inclined cylinder measurements having length-to-diameter ratios between 1.48 and 104 in nine data-sets from three peer-reviewed studies, yielding (data-set) root-mean-squared relative error values between 1.6% and 4.7%. - oai:arXiv.org:2512.06019v2 + Decay of two-dimensional superfluid turbulence over pinning surface + https://arxiv.org/abs/2509.05966 + arXiv:2509.05966v2 Announce Type: replace +Abstract: We report on the free decay of quasi-two-dimensional turbulence in superfluid $^4$He confined within nanofluidic channels. Using a pump-probe technique, we observe a complex decay of the vortex density $L(t)$ that deviates from a simple power law. The decay exhibits a universal fast transient, scaling as $L\propto t^{-2}$, followed by a slower non-universal regime that depends on the geometry and flow conditions. We demonstrate that this behavior is governed by the interplay between vortex pinning on the disordered topography of the channel walls and the mobilizing effect of the weak probe flow. A numerical model that treats pinning as a velocity-dependent effective mutual friction successfully reproduces the essential features of our experimental observations. + oai:arXiv.org:2509.05966v2 physics.flu-dyn - Fri, 12 Dec 2025 00:00:00 -0500 + cond-mat.other + Fri, 19 Dec 2025 00:00:00 -0500 replace http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Aubrey G. Jaffer, Martin S. Jaffer + Filip Novotn\'y, Marek Tal\'i\v{r}, Emil Varga - An Euler-Lagrangian Multiphysics Coupling Framework for Particle-Laden High-Speed Flows - https://arxiv.org/abs/2512.06548 - arXiv:2512.06548v3 Announce Type: replace -Abstract: Particle-laden effects in high-speed flows require a coupled Euler and Lagrangian prediction technique with varying fidelity of thermochemical models, depending on the simulation conditions of interest. This requirement makes the development of a conventional monolithic solver challenging to manage the different fidelity of the thermochemical models within a single computational framework. To address this, the present study proposes a multi-solver framework for the coupled Euler-Lagrangian predictions applicable to various particle-laden high-speed flow conditions. Volumetric and surface couplings are established between a particle solver ORACLE (OpenFOAM-based lagRAngian CoupLEr) and a thermochemical nonequilibrium flow solver based on an adaptable data exchange algorithm. The developed framework is then validated by predicting particle-laden supersonic nozzle flows and aerothermal heating around a hypersonic Martian atmospheric entry capsule. Finally, a quasi-1D approximation is proposed in conjunction with a surrogate method to efficiently and accurately predict particle-laden surface erosion, with quantified parametric uncertainty, for hypersonic aerothermal characterization. - oai:arXiv.org:2512.06548v3 - physics.flu-dyn - physics.app-ph - Fri, 12 Dec 2025 00:00:00 -0500 + Intensified optical camera with Timepix4 readout + https://arxiv.org/abs/2509.14649 + arXiv:2509.14649v4 Announce Type: replace +Abstract: We report the first characterization results of an optical time-stamping camera based on the Timepix4 chip coupled to a fully depleted optical silicon sensor and fast image intensifier, enabling sub-nanosecond scale, time-resolved imaging for single photons. The system achieves an RMS time resolution of 0.3 ns in direct detection mode without the intensifier and from 0.6 to 1.5 ns in the single-photon regime with an intensifier for different amplitude-based signal selections. This shows that Timepix4 provides a significant improvement over previous Timepix3-based cameras in terms of timing precision, and also in pixel count and data throughput. We analyze key factors that affect performance, including sensor bias and timewalk effect, and demonstrate effective correction methods to recover high temporal accuracy. The camera's temporal resolution, event-driven readout and high rate capability make it a scalable platform for a wide range of applications, including quantum optics, ultrafast imaging, and time-correlated photon counting experiments. + oai:arXiv.org:2509.14649v4 + physics.ins-det + physics.optics + Fri, 19 Dec 2025 00:00:00 -0500 replace - http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Hyeon Woo Nam, Tae Woong Jeong, Sung Min Jo + http://creativecommons.org/licenses/by/4.0/ + Erik Hogenbirk, Andrei Nomerotski, Bram Bouwens, Gabriel Diaz, Shazia Farooq, Sergei Kulkov, Erik Maddox, Ondrej Matousek, Peter Svihra, Henrique Zanoli - Overview of the Helios Design: A Practical Planar Coil Stellarator Fusion Power Plant - https://arxiv.org/abs/2512.08027 - arXiv:2512.08027v2 Announce Type: replace -Abstract: Thea Energy, Inc. has developed the preconceptual design for "Helios," a fusion power plant based on the planar coil stellarator architecture. In this overview paper, the design is summarized and the reader is referred to the other papers for more detail. The Helios design is based around a two-field-period quasi-axisymmetric ("QA") stellarator equilibrium with aspect ratio 4.5 and a novel tokamak-like X-point divertor. The natural stability, low recirculating power, and steady-state capability of the stellarator are leveraged. Stability and transport are calculated using state-of-the-art, high-fidelity codes and grounded in measured performance of existing experiments. The electromagnetic coil set is high-temperature superconducting ("HTS") and consists of 12 large, plasma-encircling coils like the toroidal field coils of a tokamak, and 324 smaller, field-shaping coils. All coils are planar and convex. A maximum of 20 T on-coil is enforced, a value which has been achieved in existing large-bore HTS coils. There is a minimum of 1.2 m between plasma and coils, leaving space for tritium breeding blanket and neutron shielding. Because of this thick shielding, all coils have a minimum 40-year operational lifetime, the same minimum lifetime of the power plant system. 1.1 GW of thermal power and 390 MW of net electric power are produced. The shaping coils are individually controllable, enabling a uniquely configurable magnetic field for relaxed manufacturing and assembly tolerances and plasma control. A practical maintenance architecture is a primary driver of the design; maintenance is performed on entire toroidal sectors that are removed from between the encircling coils. A biennial maintenance cycle is estimated to take approximately 84 days, resulting in an 88% capacity factor. Rigorous engineering constraints such as temperature and stress limits are enforced. - oai:arXiv.org:2512.08027v2 + Electron-positron pair generation using a single kJ-class laser pulse in a foam-reflector setup + https://arxiv.org/abs/2509.15853 + arXiv:2509.15853v2 Announce Type: replace +Abstract: We investigate the process of creating electron-positron pairs from laser-matter interaction in pre-ionised foam targets using particle-in-cell simulations. A high-intensity laser pulse drives electrons via direct laser acceleration up to a cone-shaped reflector. The high-energy electrons interact with the reflected laser pulse, generating abundant pairs. The effects of the plasma-channel shape on the propagation of the laser pulse and subsequent pair production is studied. The results show that the number of Compton emission and Breit-Wheeler pair creation events is highly sensitive to the diffraction of the laser due to its interaction with the foam. + oai:arXiv.org:2509.15853v2 physics.plasm-ph - Fri, 12 Dec 2025 00:00:00 -0500 + Fri, 19 Dec 2025 00:00:00 -0500 replace http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - C. P. S. Swanson, S. T. A. Kumar, D. W. Dudt, E. R. Flom, W. B. Kalb, T. G. Kruger, M. F. Martin, J. R. Olatunji, S. Pasmann, L. Z. Tang, J. von der Linden, J. Wasserman, M. Avida, A. S. Basurto, M. Dickerson, N. de Boer, M. J. Donovan, A. H. Doudna Cate, D. Fort, W. Harris, U. Khera, A. Koen, J. A. Labbate, N. Maitra, A. Ottaviano, R. K. Parmar, E. J. Paul, B. Reydel, A. van Riel, P. K. Romano, M. Savastianov, S. Saxena, S. Seethalla, S. Srinivasan, R. H. Wu, D. Nash, J. Priebe, M. Slepchenkov, S. Walsh, B. Berzin, D. A. Gates, the Thea Energy team + Oliver Mathiak, Lars Reichwein, Alexander Pukhov - Injection dynamics in spin-wave active ring oscillator (SWARO) - https://arxiv.org/abs/2512.08796 - arXiv:2512.08796v2 Announce Type: replace -Abstract: We investigated injection locking in spin-wave active ring oscillators (SWAROs) operating in the multi-mode regime. By applying external RF signals with varying frequency and power, we identified the locking behavior of individual modes and extracted the total locking ranges from spectral measurements. The results show asymmetric evolution of the lower and upper locking boundaries with drive power for the lower-frequency SWARO modes, while the highest-frequency mode exhibits nearly symmetric behavior. A maximum locking range of over 11 MHz is observed at a drive power of -10 dBm. To interpret these results, we develop an Adler-like model that captures the dependence of the locking range on drive power, showing good agreement for the higher-frequency modes. For the lowest-frequency mode, however, the model underestimates the locking range at low drive and saturates at high drive power levels, while the experimental range increases monotonically, indicating the influence of multi-mode interactions. These findings establish SWARO as a useful platform for exploring injection phenomena in spin-wave ring systems with delayed feedback and motivate the development of extended injection models that account for multi-mode dynamics. - oai:arXiv.org:2512.08796v2 - physics.app-ph - Fri, 12 Dec 2025 00:00:00 -0500 - replace - http://creativecommons.org/licenses/by-nc-nd/4.0/ - Anirban Mukhopadhyay, Ihor I. Syvorotka, Anil Prabhakar - - - Functional Percolation: A Perspective on Criticality of Form and Function - https://arxiv.org/abs/2512.09317 - arXiv:2512.09317v2 Announce Type: replace -Abstract: Understanding the physical constraints and minimal conditions that enable information processing in extended systems remains a central challenge across disciplines, from neuroscience and artificial intelligence to social and physical networks. Here we study how network connectivity both limits and enables information processing by analyzing random networks across the structural percolation transition. Using cascade-mediated dynamics as a minimal and universal mechanism for propagating state-dependent responses, we examine structural, functional, and information-theoretic observables as functions of mean degree in Erdos-Renyi networks. We find that the emergence of a giant connected component coincides with a sharp transition in realizable information processing: complex input-output response functions become accessible, functional diversity increases rapidly, output entropy rises, and directed information flow quantified by transfer entropy extends beyond local neighborhoods. These coincident transitions define a regime of functional percolation, referring to a sharp expansion of the space of realizable input-output functions at the structural percolation transition. Near criticality, networks exhibit a Pareto-optimal tradeoff between functional complexity and diversity, suggesting that percolation criticality provides a universal organizing principle for information processing in systems with local interactions and propagating influences. - oai:arXiv.org:2512.09317v2 - physics.soc-ph - cond-mat.stat-mech - cs.AI + Hybrid Delta Tracking Schemes Using a Track-Length Estimator + https://arxiv.org/abs/2510.00152 + arXiv:2510.00152v2 Announce Type: replace +Abstract: In Monte Carlo radiation transport calculations, Woodcock-delta tracking is a common alternative to the more popular surface tracking technique. In this work we introduce a delta-tracking algorithm that tallies fluxes to a structured rectilinear mesh using the track-length estimator. This development also enables hybrid surface-delta tracking algorithms, because the track-length tally can be used everywhere for scalar flux estimation regardless of which tracking algorithm is employed. We use this tallying technique to develop a novel hybrid-in-energy method. We also implement a hybrid-in-material method, like what is implemented in Serpent2. We demonstrate that these delta tracking algorithms can be used in conjunction with continuously moving surfaces. We compare these methods showing figures of merit on four time-dependent problems (multi-group and continuous energy) solved with CPU- and GPU-based computers. Our implementation of delta tracking with a track length tally modestly improves figures of merit compared to standard delta tracking with a collision estimator and surface tracking with a track length estimator (1.5X 2.5X) for a problem with significant void regions. For both multi-group and continuous energy pressurized water reactor benchmarks, standard delta tracking with a collision estimator performs best. Hybrid-in-energy methods show significant improvements (7X-11X) for a continuous energy reactor benchmark problem. + oai:arXiv.org:2510.00152v2 physics.comp-ph - Fri, 12 Dec 2025 00:00:00 -0500 + Fri, 19 Dec 2025 00:00:00 -0500 replace http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Galen J. Wilkerson + Joanna Piper Morgan, Ilham Variansyah, Kayla B. Clements, Todd S. Palmer, Kyle E. Niemeyer - A unified framework for identifying influential nodes in hypergraphs - https://arxiv.org/abs/2512.09606 - arXiv:2512.09606v2 Announce Type: replace -Abstract: Identifying influential nodes plays a pivotal role in understanding, controlling, and optimizing the behavior of complex systems, ranging from social to biological and technological domains. Yet most centrality-based approaches rely on pairwise topology and are purely structural, neglecting the higher-order interactions and the coupling between structure and dynamics. Consequently, the practical effectiveness of existing approaches remains uncertain when applied to complex spreading processes. To bridge this gap, we propose a unified framework, Initial Propagation Score (IPS), to directly embed propagation dynamics into influence assessment on higher-order networks. We analytically derive mechanism-aware influence measures by relating the early-stage dynamics and local topological characteristics to long-term outbreak sizes, and such explicit physical context endows IPS with robustness, transferability, and interpretability. Extensive experiments across multiple dynamics and more than 20 real-world hypergraphs show that IPS consistently outperforms other leading baseline centralities. Furthermore, IPS estimates node influence with only local neighborhood information, yielding computational efficiency and scalability to large-scale networks. This work underscores the necessity of considering dynamics for reliable identification of influential nodes and provides a concise principled basis for optimizing interventions in epidemiology, information diffusion, and collective intelligence. - oai:arXiv.org:2512.09606v2 - physics.soc-ph - Fri, 12 Dec 2025 00:00:00 -0500 + The impact of plasma turbulence on atomic reaction rates in detached divertors + https://arxiv.org/abs/2510.09579 + arXiv:2510.09579v2 Announce Type: replace +Abstract: Numerical modeling of the edge and scrape-off layer (SOL) must account for atomic processes such as hydrogenic ionization and recombination, charge-exchange, and line radiation. Their reaction rates depend non-linearly on density and temperature and are thus sensitive to turbulent fluctuations, whose inclusion/omission may significantly affect model outcomes. We quantify the impact of fluctuations by studying global turbulence simulations of the edge and SOL of ASDEX-Upgrade in both attached and detached conditions. While the effect of fluctuations is minimal for the attached state, pronounced discrepancies emerge in colder, detached conditions. When accounting for turbulent fluctuations, ionization and radiation rates at the detachment front are reduced by a factor of 2 when compared to mean-field calculations. The effect arises from fluctuations crossing below the ionization temperature threshold, facilitated by low mean temperature and increased fluctuation amplitudes at the detachment front. The rate reduction (rather than rate increase) is explained by the character of divertor fluctuations (negative density-temperature correlation, i.e. cold and dense blobs), notably distinct from characteristic fluctuations found at the outboard-midplane (positive correlation, i.e. hot and dense blobs). Furthermore, the cold and dense fluctuations enable efficient plasma recombination even at average temperatures above the recombination threshold. In detached conditions, the combined plasma particle source from ionization and recombination is therefore effectively reduced by at least 50% when compared to the standard mean-field source. + oai:arXiv.org:2510.09579v2 + physics.plasm-ph + Fri, 19 Dec 2025 00:00:00 -0500 replace http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Yajing Hao, Longzhao Liu, Xin Wang, Zhihao Han, Ming Wei, Zhiming Zheng, Shaoting Tang + Konrad Eder, Wladimir Zholobenko, Andreas Stegmeir, Kaiyu Zhang, Frank Jenko - Conjugate gradient for ill-posed problems: regularization by preconditioning, preconditioning by regularization - https://arxiv.org/abs/2406.04695 - arXiv:2406.04695v2 Announce Type: replace-cross -Abstract: This paper investigates using the conjugate gradient iterative solver for ill-posed problems. We show that preconditioner and Tikhonov-regularization work in conjunction. In particular when they employ the same symmetric positive semi-definite operator, a powerful Ritz analysis allows one to estimate at negligible computational cost the solution for any Tikhonov's weight. This enhanced linear solver is applied to the boundary data completion problem and as the inner solver for the optical flow estimator. - oai:arXiv.org:2406.04695v2 - math.NA - cs.NA - physics.class-ph - Fri, 12 Dec 2025 00:00:00 -0500 - replace-cross + Picosecond Precision Heavy Ion Detector for {\Lambda} Hypernuclei Lifetime Studies + https://arxiv.org/abs/2510.21375 + arXiv:2510.21375v2 Announce Type: replace +Abstract: In this paper, we present the design and preliminary performance evaluation of a new heavy ion detector for direct measurements of heavy {\Lambda} hypernuclei lifetime. The detector employs the previously developed 10 picosecond resolution Radio Frequency (RF) Timer, which converts the temporal information of incident particles into spatial coordinates of secondary or photoelectrons on a position-sensitive detector by means of circular RF scanning in the 500-1000 MHz range. Here, we report the detector design to achieve efficient suppression of accidental background and effective separation of prompt reaction products and delayed events from {\Lambda} hypernuclei decays, results of test studies carried out with RF synchronized laser as well as preliminary results obtained by using alpha particles. Dedicated Monte-Carlo simulations have been performed to estimate the detector's performance under realistic experimental conditions at RF-driven electron, photon, or proton beams. The results confirm the feasibility of the proposed design and provide a basis for upcoming experimental measurements, based on the delayed fission detection. + oai:arXiv.org:2510.21375v2 + physics.ins-det + Fri, 19 Dec 2025 00:00:00 -0500 + replace http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Ahmed Chabib (LaMcube), Jean-Francois Witz (LaMcube), Vincent Magnier (LaMcube), Pierre Gosselet (LaMcube) - - - Correcting Delocalization Error in Materials with Localized Orbitals and Linear-Response Screening - https://arxiv.org/abs/2406.07351 - arXiv:2406.07351v4 Announce Type: replace-cross -Abstract: Delocalization error prevents density functional theory (DFT) from reaching its full potential, causing problems like systematically underestimated band gaps and misaligned energy levels at interfaces. We introduce lrLOSC to correct delocalization error in materials over a wide range of band gaps. We predict eleven materials' fundamental gaps to within 0.22 eV, while offering a nonzero total energy correction; molecular properties are improved with a parallel implementation of the same theory [J. Phys. Chem. Lett. 16, 2492 (2025)]. lrLOSC is an essential step toward modeling molecules, materials, and their interfaces within the same DFT framework. - oai:arXiv.org:2406.07351v4 - cond-mat.mtrl-sci - physics.chem-ph - Fri, 12 Dec 2025 00:00:00 -0500 - replace-cross - http://creativecommons.org/licenses/by-sa/4.0/ - Jacob Z. Williams, Weitao Yang + Simon Zhamkochyan, Sergey Abrahamyan, Amur Margaryan, Hayk Elbakyan, Aram Kakoyan, Samvel Mayilyan, Artashes Papyan, Hasmik Rostomyan, Anna Safaryan, Gagik Sughyan, Narek Margaryan, Garnik Ayvazyan, John Annand, Kenneth Livingston, Rachel Montgomery, Patrick Achenbach, Josef Pochodzalla, Dimiter Balabanski, Satoshi Nakamura, Ani Aprahamian, Vanik Kakoyan - Dynamical signature of vortex mass in Fermi superfluids - https://arxiv.org/abs/2410.12417 - arXiv:2410.12417v2 Announce Type: replace-cross -Abstract: Quantum vortices are commonly described as funnel-like objects around which the superfluid swirls, and their motion is typically modeled in terms of massless particles. Here we show that in Fermi superfluids the normal component confined in the vortex core provides the vortex with a finite inertial mass. This inertia imparts an unambiguous signature to the dynamic behavior of vortices, specifically manifesting as small-amplitude transverse oscillations which remarkably follow the prediction of a simple point-like model supplemented by an effective mass. We demonstrate this phenomenon through large-scale time-dependent simulations of Fermi superfluids across a wide range of interaction parameters, at both zero and finite temperatures, and for various initial conditions. Our findings pave the way for the exploration of inertial effects in superfluid vortex dynamics. - oai:arXiv.org:2410.12417v2 - cond-mat.quant-gas + Data-driven Augmentation of a Turbulence Model in Three-dimensional Separated Flows + https://arxiv.org/abs/2510.22469 + arXiv:2510.22469v2 Announce Type: replace +Abstract: Classic turbulence models often struggle to accurately predict complex flows. Although data-driven techniques have addressed these shortcomings, most existing research has concentrated on two-dimensional (2D) cases. This study bridges this gap by enhancing a data-driven turbulence model, the SST-CND (shear stress transport-conditioned) model, which was originally trained on 2D separated flows, in 3D scenarios. An additional correction term, \b{eta}_3D, is introduced to account for 3D effects. The distribution of this term is determined through a 3D field inversion process using high-fidelity data obtained from the flow around a cube. An algebraic expression for \b{eta}_3D is then derived through symbolic regression and formulated to degrade to zero in 2D cases. The performance of the resulting SST-CND3D model is evaluated across a range of flows. In 2D flows, the SST-CND3D model performs identically to its 2D-trained predecessor. However, the model exhibits superior performance in 3D flows, such as the flow around the complex JAXA standard model high-lift configuration. These findings indicate that a sequential approach, constructing a 3D correction term that vanishes in 2D on top of a 2D-trained model, constitutes a promising method for developing data-driven turbulence models that perform accurately in 3D while preserving their effectiveness in 2D. + oai:arXiv.org:2510.22469v2 physics.flu-dyn - Fri, 12 Dec 2025 00:00:00 -0500 - replace-cross + Fri, 19 Dec 2025 00:00:00 -0500 + replace http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - 10.1103/zcb4-dldf - Phys. Rev. A 112, L051306 (2025) - Andrea Richaud, Matteo Caldara, Massimo Capone, Pietro Massignan, Gabriel Wlaz{\l}owski + Chenyu Wu, Shaoguang Zhang, Yufei Zhang - Convection can enhance the capacitive charging of porous electrodes - https://arxiv.org/abs/2410.12653 - arXiv:2410.12653v2 Announce Type: replace-cross -Abstract: Charge transport in porous electrodes is foundational for modern energy storage technologies like supercapacitors, fuel cells, and batteries. Supercapacitors in particular rely solely on storing energy in charged pores. Here, we simulate the charging of a single electrolyte-filled pore using the modified Poisson-Nernst-Planck and Navier-Stokes equations. We find that electroconvection can substantially speed up the charging dynamics. We uncover the fundamental mechanism of electroconvection during pore charging through an analytical model that predicts the induced flow field and the electric current arising due to convection. Our findings suggest that convection is especially important in the limit of slender pores with thin electric double layers, and becomes significant beyond a certain threshold voltage that is an inherent electrolyte property. - oai:arXiv.org:2410.12653v2 - cond-mat.soft - physics.flu-dyn - Fri, 12 Dec 2025 00:00:00 -0500 - replace-cross + An Efficient Regional Storm Surge Surrogate Model Training Strategy Under Evolving Landscape and Climate Scenarios + https://arxiv.org/abs/2511.07269 + arXiv:2511.07269v3 Announce Type: replace +Abstract: Coastal communities face significant risk from storm-induced coastal flooding, which causes substantial societal and economic losses worldwide. Machine learning techniques have increasingly been integrated into coastal hazard modeling, particularly for storm surge prediction, due to advances in computational capacity. However, incorporating multiple projected future climate and landscape scenarios requires extensive numerical simulations of synthetic storm suites over large geospatial domains, resulting in rapidly escalating computational costs. This study proposes a cost-effective training data reduction strategy for machine learning based storm surge surrogate models that enables efficient incorporation of new future scenarios while minimizing computational burden. The proposed strategy reduces training data across three dimensions: grid points, input features, and storm suite size. Reducing the storm suite size for future scenario simulations is highly effective in guiding numerical simulations, yielding substantial reductions in simulation cost. The performance of surrogate models trained on reduced datasets was evaluated using different machine learning algorithms. Results demonstrate that the proposed reduction strategy is robust across different model types. When trained using 5,000 out of 80,000 grid points, 10 out of 12 input features, and 60 out of 90 storms, the total training dataset is reduced to approximately 5% of its original size. Despite this reduction, the trained model achieves a correlation coefficient of 0.94, comparable to models trained on the full dataset. In addition, storm selection methodologies are introduced to support efficient storm set expansion for future scenario analyses. + oai:arXiv.org:2511.07269v3 + physics.ao-ph + Fri, 19 Dec 2025 00:00:00 -0500 + replace http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - 10.1073/pnas.2504322122 - Proceedings of the National Academy of Sciences of the United States of America 122, e2504322122 (2025) - Aaron D. Ratschow, Alexander J. Wagner, Mathijs Janssen, Steffen Hardt + Ziyue Liu, Mohammad Ahmadi Gharehtoragh, Brenna Kari Losch, David R. Johnson - Bringing together African & European research communities with an inclusive astronomy conference - https://arxiv.org/abs/2411.12834 - arXiv:2411.12834v2 Announce Type: replace-cross -Abstract: We report on an international scientific conference, where we brought together African and European academic astronomers. This aimed to bridge the gap between those in position of privilege, with ease of access to international events (i.e., the typical experience of academics in Western institutions), with those historically excluded (affecting the majority of African scientists/institutions). We describe how we designed the conference around cutting-edge research problems, but with a parallel focus on building networking and professional relationships. Significant effort went into: (1) ensuring a diversity of participants; (2) practically and financially supporting those who may never have attended an international conference and; (3) creating an inclusive and supportive environment through a careful programme of activities, both before and during the event. Maintaining scientific integrity was a core commitment throughout. We summarise successes, challenges and lessons learnt from organising this conference. We also present feedback obtained from participants immediately after the conference, and a discussion of some longer-term impacts, which we identified around 1 year later. We found an overall achievement of our objectives, and multiple longer-term benefits. With this report we provide some key recommendations for groups, from any research field, who may wish to lead similar initiatives. - oai:arXiv.org:2411.12834v2 - astro-ph.IM - astro-ph.GA - physics.ed-ph + Friendship-paradox paradox: Do most people's friends really have more friends than they do? + https://arxiv.org/abs/2511.13957 + arXiv:2511.13957v5 Announce Type: replace +Abstract: The classical friendship paradox asserts that, on average, an individual's neighbors have a higher degree than the individual. This statement concerns network-level means and does not describe how often a typical node is locally dominated by its neighbors. Motivated by this distinction, we develop a framework that separates mean-based friendship paradox inequalities from two majority-type quantities: a global fraction measuring how many nodes have a degree smaller than the mean degree of their neighbors, and a local fraction based on hub centrality that measures how many nodes are dominated in a median-based sense. We show that neither fraction is constrained by the classical friendship paradox and that they can behave independently of each other. A simple example and two empirical networks illustrate how quadrant patterns in the joint distribution of a node's degree and its neighbors' degree determine the signs and magnitudes of the two fractions, and how left- or right-skewed degree distributions of neighboring nodes can yield opposite conclusions for mean-based and median-based comparisons. The resulting framework offers a clearer distinction between population averages and local majority relations and provides a foundation for future analyses of local advantage, disadvantage, and perception asymmetry in complex networks. + oai:arXiv.org:2511.13957v5 physics.soc-ph - Fri, 12 Dec 2025 00:00:00 -0500 - replace-cross - http://creativecommons.org/licenses/by/4.0/ - Chris M. Harrison (Newcastle University), Leah Morabito (Durham University), Ann Njeri (Newcastle University, on behalf of the Organising Committees) - - - Enhanced Spatial Clustering of Single-Molecule Localizations with Graph Neural Networks - https://arxiv.org/abs/2412.00173 - arXiv:2412.00173v2 Announce Type: replace-cross -Abstract: Single-molecule localization microscopy generates point clouds corresponding to fluorophore localizations. Spatial cluster identification and analysis of these point clouds are crucial for extracting insights about molecular organization. However, this task becomes challenging in the presence of localization noise, high point density, or complex biological structures. Here, we introduce MIRO (Multifunctional Integration through Relational Optimization), an algorithm that uses recurrent graph neural networks to transform the point clouds in order to improve clustering efficiency when applying conventional clustering techniques. We show that MIRO supports simultaneous processing of clusters of different shapes and at multiple scales, demonstrating improved performance across varied datasets. Our comprehensive evaluation demonstrates MIRO's transformative potential for single-molecule localization applications, showcasing its capability to revolutionize cluster analysis and provide accurate, reliable details of molecular architecture. In addition, MIRO's robust clustering capabilities hold promise for applications in various fields such as neuroscience, for the analysis of neural connectivity patterns, and environmental science, for studying spatial distributions of ecological data. - oai:arXiv.org:2412.00173v2 - cs.LG - physics.bio-ph - physics.data-an - q-bio.QM - Fri, 12 Dec 2025 00:00:00 -0500 - replace-cross + cond-mat.stat-mech + Fri, 19 Dec 2025 00:00:00 -0500 + replace http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - 10.1038/s41467-025-65557-7 - Nat Commun 16, 9693 (2025) - Jes\'us Pineda, Sergi Mas\'o-Orriols, Montse Masoliver, Joan Bertran, Mattias Goks\"or, Giovanni Volpe, Carlo Manzo - - - Eigenstructure Analysis of Bloch Wave and Multislice Formulations for Dynamical Scattering in Transmission Electron Microscopy - https://arxiv.org/abs/2412.21119 - arXiv:2412.21119v2 Announce Type: replace-cross -Abstract: We investigate the eigenstructure of matrix formulations used for modeling scattering processes within materials in transmission electron microscopy. Dynamical scattering is crucial for describing the interaction between an electron wave and the material under investigation. Unlike the Bloch wave formulation, which defines the transmission function via the scattering matrix, the traditional multislice method is lacking a pure transmission function due to the entanglement of electron waves with the propagation function. To address this, we reformulate the multislice method into a matrix framework, which we refer to as the transmission matrix. This allows a direct comparison to the scattering matrix derived from Bloch waves in terms of their eigenstructures. Through theory, we demonstrate their equivalence with eigenvectors related by a two-dimensional Fourier matrix, given that the eigenvalue angles differ by modulo $2\pi n$ (integer $n$). We numerically verify our findings as well as demonstrate the application of the eigenstructure for the estimation of the mean inner potential. - oai:arXiv.org:2412.21119v2 - cond-mat.mtrl-sci - cond-mat.mes-hall - physics.comp-ph - Fri, 12 Dec 2025 00:00:00 -0500 - replace-cross - http://creativecommons.org/licenses/by/4.0/ - Arya Bangun, Oleh Melnyk, Benjamin M\"arz + Sang Hoon Lee - AI-Newton: A Concept-Driven Physical Law Discovery System without Prior Physical Knowledge - https://arxiv.org/abs/2504.01538 - arXiv:2504.01538v2 Announce Type: replace-cross -Abstract: While current AI-driven methods excel at deriving empirical models from individual experiments, a significant challenge remains in uncovering the common fundamental physics that underlie these models -- a task at which human physicists are adept. To bridge this gap, we introduce AI-Newton, a novel framework for concept-driven scientific discovery. Our system autonomously derives general physical laws directly from raw, multi-experiment data, operating without supervision or prior physical knowledge. Its core innovations are twofold: (1) proposing interpretable physical concepts to construct laws, and (2) progressively generalizing these laws to broader domains. Applied to a large, noisy dataset of mechanics experiments, AI-Newton successfully rediscovers foundational and universal laws, such as Newton's second law, the conservation of energy, and the universal gravitation. This work represents a significant advance toward autonomous, human-like scientific discovery. - oai:arXiv.org:2504.01538v2 - cs.AI - cs.LG - cs.SC - hep-ph - physics.class-ph - Fri, 12 Dec 2025 00:00:00 -0500 - replace-cross + Real-time 3D Ultrasonic Needle Tracking with a Photoacoustic Beacon + https://arxiv.org/abs/2511.20514 + arXiv:2511.20514v3 Announce Type: replace +Abstract: Many minimally invasive procedures, such as core needle biopsy of focal liver lesions, nerve blocks, and fetal and vascular interventions, are typically performed under ultrasound guidance, which provides real-time, high-resolution visualisation of tissue anatomy. Accurate and efficient localisation of the needle tip relative to patient anatomy is essential for guiding the needle towards the procedure target, avoiding adverse events and reducing the need for repeat procedures. However, the 3D nature of the procedure and poor image contrast of the needle in heterogeneous tissue or at steep insertion angles often leads to confusion over the true location of the tip within the 2D guidance images, and existing methods to enhance needle visibility largely remain limited to 2D. Here, we present a novel interventional ultrasound system capable of 2D B-mode imaging and 3D needle tracking. The tip location is determined from the time-of-flight of ultrasound generated by a photoacoustic beacon embedded in the needle bevel and received by a sparse receiver array distributed around the imaging system's curvilinear ultrasound probe. The measured tracking accuracy was better than 2 mm for depths up to 140 mm in water, and approximately 2 mm on average in an ex vivo tissue phantom, with referenced positions derived from X-ray CT. In a usability study involving 12 clinicians performing biopsy procedures in a ex vivo tissue phantom, the failure rate was reduced by 35 %, from 15.8 % to 10.3 % after only a few minutes of training. These results demonstrate that the proposed system has strong potential to support a wide range of minimally invasive procedures by enabling clinicians to accurately target anatomical structures with millimetre-level precision, improving the efficiency and effectiveness of diagnostic sampling and therapeutic delivery or ablation, and reducing the risk of adverse events. + oai:arXiv.org:2511.20514v3 + physics.med-ph + Fri, 19 Dec 2025 00:00:00 -0500 + replace http://creativecommons.org/licenses/by/4.0/ - You-Le Fang, Dong-Shan Jian, Xiang Li, Yan-Qing Ma - - - Demonstration of Efficient Radon Removal by Silver-Zeolite in a Dark Matter Detector - https://arxiv.org/abs/2505.07979 - arXiv:2505.07979v2 Announce Type: replace-cross -Abstract: We present the performance of an efficient radon trap using silver-zeolite Ag-ETS-10, measured with a spherical proportional counter filled with an argon/methane mixture. Our study compares the radon reduction capabilities of silver-zeolite and the widely used activated charcoal, both at room temperature. We demonstrate that silver-zeolite significantly outperforms activated charcoal by three orders of magnitude in radon capture. Given that radon is a major background contaminant in rare event searches, our findings highlight silver-zeolite as a highly promising adsorbent, offering compelling operational advantages for both current and future dark matter and neutrino physics experiments. Furthermore, this not only offers great promise for developing future radon reduction systems in underground laboratories, but also paves the way for innovative, multidisciplinary advancements with far-reaching implications in science, engineering and environmental health. - oai:arXiv.org:2505.07979v2 - hep-ex - physics.ins-det - Fri, 12 Dec 2025 00:00:00 -0500 - replace-cross - http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Daniel Durnford, Yuqi Deng, Carter Garrah, Patrick B. O'Brien, Philippe Gros, Michel Gros, Jos\'e Busto, Steven Kuznicki, Marie-C\'ecile Piro + Christian Baker, Weidong Liang, Richard Colchester, Peng Lei, Francois Joubert, Sebastien Ourselin, Simeon West, Adrien Desjardins, Athanasios Diamantopoulos, Wenfeng Xia - Potential Landscapes Reveal Spatiotemporal Structure in Urban Mobility: Hodge Decomposition and Principal Component Analysis of Tokyo Before and During COVID-19 - https://arxiv.org/abs/2505.20929 - arXiv:2505.20929v4 Announce Type: replace-cross -Abstract: Understanding human mobility is vital to solving societal challenges, such as epidemic control and urban transportation optimization. Recent advancements in data collection now enable the exploration of dynamic mobility patterns in human flow. However, the vast volume and complexity of mobility data make it difficult to interpret spatiotemporal patterns directly, necessitating effective information reduction. The core challenge is to balance data simplification with information preservation: methods must retain location-specific information about human flows from origins to destinations while reducing the data to a comprehensible level. This study proposes a two-step dimensionality reduction framework: First, combinatorial Hodge theory is applied to the given origin--destination (OD) matrices with timestamps to construct a set of potential landscapes of human flow, preserving imbalanced trip information between locations. Second, principal component analysis (PCA) expresses the time series of potential landscapes as a linear combination of a few static spatial components, with their coefficients representing temporal variations. The framework systematically decouples the spatial and temporal components of the given data. By implementing this two-step reduction method, we reveal large weight variations during a pandemic, characterized by an overall decline in mobility and stark contrasts between weekdays and holidays. These findings demonstrate the effectiveness of our framework in uncovering complex mobility patterns and its potential to inform urban planning and public health interventions. - oai:arXiv.org:2505.20929v4 - cs.SI - physics.soc-ph - stat.AP - Fri, 12 Dec 2025 00:00:00 -0500 - replace-cross + Parity Nonconservation in Rb and Sr$^+$ due to Low-Mass Vector Boson + https://arxiv.org/abs/2512.12882 + arXiv:2512.12882v2 Announce Type: replace +Abstract: We calculate the parity non-conserving (PNC) electric-dipole ($E1$) transition amplitudes for the $5s - 6s$ and $5s - 4d_{3/2}$ transitions in Rb and Sr$^+$. Our results include both the nuclear-spin-independent and nuclear-spin-dependent contributions, with particular emphasis on the potential effects of a hypothetical additional $Z'$-boson. We highlight possible advantages of using light atoms in searches for such new interaction. The ratio of the contribution of a low mass $Z'$-boson to the contribution of the Standard model $Z$-boson to PNC effects increases rapidly (faster than $1/Z^2$) with decreasing nuclear charge $Z$. Another advantage is that theoretical interpretations of experiments in lighter systems may be carried out with a higher accuracy than that in Cs, Ba$^+$, Fr and Ra$^+$. + oai:arXiv.org:2512.12882v2 + physics.atom-ph + Fri, 19 Dec 2025 00:00:00 -0500 + replace http://creativecommons.org/licenses/by/4.0/ - Yunhan Du, Takaaki Aoki, Naoya Fujiwara + V. A. Dzuba, V. V. Flambaum, G. K. Vong - Efficient absolute interface energy calculations for heterostructures: Synergy between localized basis sets and surface passivation techniques - https://arxiv.org/abs/2506.03769 - arXiv:2506.03769v2 Announce Type: replace-cross -Abstract: Heterostructures combining diverse physico-chemical properties are increasingly in demand for a wide range of applications in modern science and technology. However, despite their importance in materials science, accurately determining absolute interface energies remains a major challenge. Here, we present a computationally efficient framework for determining interface energies by incorporating a surface passivation technique, demonstrated using pseudo H passivation with a localized basis set method and an explicit chemical potential. This framework is applied to calculate absolute interface energies and analyze the electronic properties of quasi lattice matched and lattice mismatched III and V on Si interfaces, with results compared to conventional reconstructed surface calculations. By combining localized basis sets with surface passivation techniques, this framework allows for accurate estimation of absolute interface energies in heterogeneous material systems. This approach effectively addresses issues associated with surface reconstructions while significantly reducing computational costs within the framework of density functional theory, and moreover offers considerable potential for calculating interface energies across diverse material systems. - oai:arXiv.org:2506.03769v2 - cond-mat.mtrl-sci + Lagrangian Heterogeneous Multiscale Method (LHMM) for Simulating Polymer Solutions/Melts Behavior under Complex Flows using DPD-SPH + https://arxiv.org/abs/2512.13267 + arXiv:2512.13267v2 Announce Type: replace +Abstract: We present a Lagrangian Heterogeneous Multiscale Method (LHMM) for simulating the non-Newtonian rheology of polymer melts in complex two-dimensional flows. The method couples Dissipative Particle Dynamics (DPD) at the microscale with a GENERIC-compliant Smoothed Particle Hydrodynamics (SPH) at the macroscale, in a concurrent framework, overcoming the limitations of traditional Eulerian-based methods in capturing long-memory and history-dependent effects. At the microscale, DPD serves as a virtual rheometer, employing FENE (Finitely Extensible Nonlinear Elastic) bead-spring polymer chains. This approach provides key rheological properties, including shear-thinning and zero-shear-rate viscosities, relaxation times, and viscoelastic dynamics, which are quantified via Carreau-Yasuda fitting and spectral analysis. The LHMM couples SPH-derived strain rates with microscopic stress responses using the Irving-Kirkwood formalism. This approach enables a concurrent interaction between macroscopic strain rates and microscopic stress tensors, ensuring a consistent viscoelastic response across scales. The method is validated against benchmark flows, including Reverse Poiseuille Flow and flow through a Periodic Array of Cylinders, across Weissenberg numbers $0.5 < \text{Wi} < 30$ and low Reynolds numbers ($\text{Re} < 1$). A final demonstration of flow in a 2D porous medium highlights LHMM's capability to handle highly heterogeneous geometries. The LHMM is implemented in LAMMPS, making it suitable for integrating multiple models to describe microscales. In contrast, large-scale simulations efficiently utilize GPU and CPU resources, managing multiple coupling and time-scaling levels to maintain numerical stability and accuracy. The framework offers a predictive, constitutive-free tool that links microscopic polymer dynamics to macroscopic flow behavior, making it suitable for multiscale applications. + oai:arXiv.org:2512.13267v2 + physics.flu-dyn physics.app-ph - physics.chem-ph - physics.comp-ph - Fri, 12 Dec 2025 00:00:00 -0500 - replace-cross - http://creativecommons.org/licenses/by/4.0/ - Sreejith Pallikkara Chandrasekharan, Sofia Apergi, Charles Cornet, Laurent Pedesseau - - - Synchronization of Dirac-Bianconi driven oscillators - https://arxiv.org/abs/2506.20163 - arXiv:2506.20163v2 Announce Type: replace-cross -Abstract: In dynamical systems on networks, one assigns the dynamics to nodes, which are then coupled via links. This approach does not account for group interactions and dynamics on links and other higher dimensional structures. Higher-order network theory addresses this by considering variables defined on nodes, links, triangles, and higher-order simplices, called topological signals (or cochains). Moreover, topological signals of different dimensions can interact through the Dirac-Bianconi operator, which allows coupling between topological signals defined, for example, on nodes and links. Such interactions can induce various dynamical behaviors, for example, periodic oscillations. The oscillating system consists of topological signals on nodes and links whose dynamics are driven by the Dirac-Bianconi coupling, hence, which we call it Dirac-Bianconi driven oscillator. Using the phase reduction method, we obtain a phase description of this system and apply it to the study of synchronization between two such oscillators. This approach offers a way to analyze oscillatory behaviors in higher-order networks beyond the node-based paradigm, while providing a ductile modeling tool for node- and edge-signals. - oai:arXiv.org:2506.20163v2 - nlin.PS - math-ph - math.MP - nlin.AO - physics.comp-ph - Fri, 12 Dec 2025 00:00:00 -0500 - replace-cross - http://creativecommons.org/licenses/by/4.0/ - Riccardo Muolo, Iv\'an Le\'on, Yuzuru Kato, Hiroya Nakao + Fri, 19 Dec 2025 00:00:00 -0500 + replace + http://creativecommons.org/licenses/by-nc-nd/4.0/ + Edgar A. Pati\~no-Nari\~no, Nicolas Moreno, Marco Ellero - Addressing the Infinite Variance Problem in Fermionic Monte Carlo Simulations: Retrospective Error Remediation and the Exact Bridge Link Method - https://arxiv.org/abs/2507.08937 - arXiv:2507.08937v2 Announce Type: replace-cross -Abstract: We revisit the infinite variance problem in fermionic Monte Carlo simulations, which is widely encountered in areas ranging from condensed matter to nuclear and high-energy physics. The different algorithms, which we broadly refer to as determinantal quantum Monte Carlo (DQMC), are applied in many situations and differ in details, but they share a foundation in field theory, and often involve fermion determinants whose symmetry properties make the algorithm sign-problem-free. We show that the infinite variance problem arises as the observables computed in DQMC tend to form heavy-tailed distributions. To remedy this issue retrospectively, we introduce a tail-aware error estimation method to correct the otherwise unreliable estimates of confidence intervals. Furthermore, we demonstrate how to perform DQMC calculations that eliminate the infinite variance problem for a broad class of observables. Our approach is an exact bridge link method, which involves a simple and efficient modification to the standard DQMC algorithm. The method introduces no systematic bias and is straightforward to implement with minimal computational overhead. Our results establish a practical and robust solution to the infinite variance problem, with broad implications for improving the reliability of a variety of fundamental fermion simulations. - oai:arXiv.org:2507.08937v2 - cond-mat.str-el + An interpretation of the Brownian bridge as a physics-informed prior for the Poisson equation + https://arxiv.org/abs/2503.00213 + arXiv:2503.00213v2 Announce Type: replace-cross +Abstract: Many inverse problems require reconstructing physical fields from limited and noisy data while incorporating known governing equations. A growing body of work within probabilistic numerics formalizes such tasks via Bayesian inference in function spaces by assigning a physically meaningful prior to the latent field. In this work, we demonstrate that Brownian bridge Gaussian processes can be viewed as a softly-enforced physics-constrained prior for the Poisson equation. We first show equivalence between the variational problem associated with the Poisson equation and a kernel ridge regression objective. Then, through the connection between Gaussian process regression and kernel methods, we identify a Gaussian process for which the posterior mean function and the minimizer to the variational problem agree, thereby placing this PDE-based regularization within a fully Bayesian framework. This connection allows us to probe different theoretical questions, such as convergence and behavior of inverse problems. We then develop a finite-dimensional representation in function space and prove convergence of the projected prior and resulting posterior in Wasserstein distance. Finally, we connect the method to the important problem of identifying model-form error in applications, providing a diagnostic for model misspecification. + oai:arXiv.org:2503.00213v2 + stat.ML + cs.LG physics.comp-ph - Fri, 12 Dec 2025 00:00:00 -0500 + Fri, 19 Dec 2025 00:00:00 -0500 replace-cross http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - 10.1103/s4zw-qt8f - Phys. Rev. E 112, 065309 (2025) - Zhou-Quan Wan, Shiwei Zhang + Alex Alberts, Ilias Bilionis - RoFt-Mol: Benchmarking Robust Fine-Tuning with Molecular Graph Foundation Models - https://arxiv.org/abs/2509.00614 - arXiv:2509.00614v3 Announce Type: replace-cross -Abstract: In the era of foundation models, fine-tuning pre-trained models for specific downstream tasks has become crucial. This drives the need for robust fine-tuning methods to address challenges such as model overfitting and sparse labeling. Molecular graph foundation models (MGFMs) face unique difficulties that complicate fine-tuning. These models are limited by smaller pre-training datasets and more severe data scarcity for downstream tasks, both of which require enhanced model generalization. Moreover, MGFMs must accommodate diverse objectives, including both regression and classification tasks. To better understand and improve fine-tuning techniques under these conditions, we classify eight fine-tuning methods into three mechanisms: weight-based, representation-based, and partial fine-tuning. We benchmark these methods on downstream regression and classification tasks across supervised and self-supervised pre-trained models in diverse labeling settings. This extensive evaluation provides valuable insights and informs the design of a refined robust fine-tuning method, ROFT-MOL. This approach combines the strengths of simple post-hoc weight interpolation with more complex weight ensemble fine-tuning methods, delivering improved performance across both task types while maintaining the ease of use inherent in post-hoc weight interpolation. - oai:arXiv.org:2509.00614v3 - cs.LG - physics.chem-ph - Fri, 12 Dec 2025 00:00:00 -0500 + Enhanced Variational Quantum Kolmogorov-Arnold Network + https://arxiv.org/abs/2503.22604 + arXiv:2503.22604v3 Announce Type: replace-cross +Abstract: The Kolmogorov-Arnold Network (KAN) is a novel multi-layer network model recognized for its efficiency in neuromorphic computing, where synapses between neurons are trained linearly. Computations in KAN are performed by generating a polynomial vector from the state vector and layer-wise trained synapses, enabling efficient processing. While KAN can be implemented on quantum computers using block encoding and Quantum Signal Processing, these methods require fault-tolerant quantum devices, making them impractical for current Noisy Intermediate-Scale Quantum (NISQ) hardware. We propose the Enhanced Variational Quantum Kolmogorov-Arnold Network (EVQKAN) to overcome this limitation, which emulates KAN through variational quantum algorithms. The EVQKAN ansatz employs a tiling technique to emulate layer matrices, leading to significantly higher accuracy compared to conventional Variational Quantum Kolmogorov-Arnold Network (VQKAN) and Quantum Neural Networks (QNN), even with a smaller number of layers. EVQKAN achieves superior performance with a single-layer architecture, whereas QNN and VQKAN typically struggle. Additionally, EVQKAN eliminates the need for Quantum Signal Processing, enhancing its robustness to noise and making it well-suited for practical deployment on NISQ-era quantum devices. + oai:arXiv.org:2503.22604v3 + quant-ph + physics.comp-ph + Fri, 19 Dec 2025 00:00:00 -0500 replace-cross http://creativecommons.org/licenses/by/4.0/ - Shikun Liu, Deyu Zou, Nima Shoghi, Victor Fung, Kai Liu, Pan Li + Hikaru Wakaura, Rahmat Mulyawan, Andriyan B. Suksmono - Topological transitions controlled by the interaction range - https://arxiv.org/abs/2509.24682 - arXiv:2509.24682v2 Announce Type: replace-cross -Abstract: We study a one-dimensional topological model featuring a Su-Schrieffer-Heeger type pattern of nearest-neighbor couplings in combination with the longer-range interactions exponentially decaying with the distance. We demonstrate that even relatively weak long-range couplings can trigger the topological transition if their range is large enough. This provides an additional facet in the control of topological phases. - oai:arXiv.org:2509.24682v2 - cond-mat.mes-hall + Scalable low-latency entanglement distribution for distributed quantum computing + https://arxiv.org/abs/2504.05567 + arXiv:2504.05567v3 Announce Type: replace-cross +Abstract: Practical distributed quantum computing and error correction require quantum networks with high-qubit-rate, high-fidelity, and low-reconfiguration-latency. Unfortunately, current approaches are limited by fundamental constraints: single-channel entanglement rates remain at the MHz level with millisecond-level reconfiguration, which is insufficient for fault-tolerant distributed quantum computing. Here, we propose a quantum network architecture that leverages reconfigurable quantum interfaces and wavelength-selective switches to overcome bandwidth and latency constraints. By tuning the frequency and temporal modes of photonic qubits across dense wavelength division multiplexing (DWDM) channels, our protocol achieves an entanglement generation rate of up to 183.4 MHz based on our comprehensive modeling of the networked cold atom computing systems. Our architecture enables nanosecond-scale network reconfiguration with low loss, low infidelity, and high dimensionality. Our modeling and simulation are designed for deployable distributed quantum computing and error correction, integrating the quantum interface, network switching, circuit compilation, and execution into a unified framework. The proposed architecture is fully compatible with industry-standard DWDM infrastructure, providing a scalable and cost-effective foundation for distributed quantum computing. + oai:arXiv.org:2504.05567v3 + quant-ph physics.optics - Fri, 12 Dec 2025 00:00:00 -0500 - replace-cross - http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Vlad Simonyan, Maxim A. Gorlach - - - Simulation of Muon-induced Backgrounds for the Colorado Underground Research Institute (CURIE) - https://arxiv.org/abs/2510.06150 - arXiv:2510.06150v2 Announce Type: replace-cross -Abstract: We present a comprehensive Monte Carlo simulation of muon-induced backgrounds for the Colorado Underground Research Institute (CURIE), a shallow-underground facility with $\approx 415$~m.w.e. overburden. Using coupled \textsc{mute} and \textsc{geant4} frameworks, we characterize the production and transport of muon-induced secondaries through site-specific rock compositions and geometries, establishing a proof-of-concept for high-precision, end-to-end simulations. Our simulations employ angular-dependent muon energy distributions, which improve secondary flux accuracy. For the Subatomic Particle Hideout and Cryolab I research spaces, we predict total muon-induced neutron fluxes of $(8.52 \pm 1.30_{\text{sys}}) \times 10^{-3}$~m$^{-2}$s$^{-1}$ and $(8.86 \pm 1.62_{\text{sys}}) \times 10^{-3}$~m$^{-2}$s$^{-1}$, respectively. Additionally, we develop a Depth-Intensity Relation (DIR) to predict the muon-induced neutron flux as a function of facility depth, which is consistent with measurements across a broad range of underground depths. These results provide quantitative background predictions for experimental design and sensitivity projections at shallow- and deep-underground facilities. They further demonstrate that local geology and overburden geometry influence muon-induced secondary yields and energy spectra, emphasizing the need for site-specific simulations for accurate underground background characterization. Therefore, the simulation framework has been made publicly available at \href{https://doi.org/10.5281/zenodo.17196581}{https://doi.org/10.5281/zenodo.17196581}, for the broader low-background physics community to enable meaningful inter-facility comparisons. - oai:arXiv.org:2510.06150v2 - hep-ex - physics.comp-ph - physics.ins-det - Fri, 12 Dec 2025 00:00:00 -0500 - replace-cross - http://creativecommons.org/licenses/by-nc-sa/4.0/ - Dakota K. Keblbeck, Eric Mayotte, Uwe Greife, Kyle G. Leach, Wouter Van De Pontseele, Caitlyn Stone-Whitehead, Luke Wanner, Grace Wagner - - - Time crystalline solitons and their stochastic dynamics in a driven-dissipative \phi^4 model - https://arxiv.org/abs/2510.19587 - arXiv:2510.19587v2 Announce Type: replace-cross -Abstract: Periodically driven systems provide unique opportunities to investigate the dynamics of topological excitations far from equilibrium. In this paper, we report a time-crystalline soliton (TCS) state in a driven-dissipative $\phi^4$ model. This state exhibits spontaneous breaking of discrete time-translational symmetry while simultaneously displaying spatial soliton behavior. During time evolution, the soliton pattern periodically oscillates between kink and anti-kink configurations. We further study TCS dynamics under noise, demonstrating that soliton random walk can induce a dynamical transition between two distinct $Z_2$ symmetry-breaking time-crystalline phases in time domain. Finally, we examine the annihilation of two spatially separated TCSs under noise. Importantly, in contrast to the confined behavior of time-crystalline monopoles reported in [Phys. Rev. Lett. 131, 056502 (2023)], the dynamics of time-crystalline solitons is deconfined despite the nonequilibrium nature of our model: the statistically averaged annihilation time scales as a power law with the solitons' initial separation. - oai:arXiv.org:2510.19587v2 - cond-mat.stat-mech - physics.comp-ph - Fri, 12 Dec 2025 00:00:00 -0500 + Fri, 19 Dec 2025 00:00:00 -0500 replace-cross http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Xingdong Luo, Zhizhen Chen - - - Impacting spheres: from liquid drops to elastic beads - https://arxiv.org/abs/2510.24855 - arXiv:2510.24855v2 Announce Type: replace-cross -Abstract: A liquid drop impacting a non-wetting rigid substrate laterally spreads, then retracts, and finally jumps off again. An elastic solid, by contrast, undergoes a slight deformation, contacts briefly, and bounces. The impact force on the substrate - crucial for engineering and natural processes - is classically described by Wagner's (liquids) and Hertz's (solids) theories. This work bridges these limits by considering a generic viscoelastic medium. Using direct numerical simulations, we study a viscoelastic sphere impacting a rigid, non-contacting surface and quantify how the elasticity number ($El$, dimensionless elastic modulus) and the Weissenberg number ($Wi$, dimensionless relaxation time) dictate the impact force. We recover the Newtonian liquid response as either $El \to 0$ or $Wi \to 0$, and obtain elastic-solid behavior in the limit $Wi \to \infty$ and $El \ne 0$. In this elastic-memory limit, three regimes emerge - capillary-dominated, Wagner scaling, and Hertz scaling - with a smooth transition from the Wagner to the Hertz regime. Sweeping $Wi$ from 0 to $\infty$ reveals a continuous shift from materials with no memory to materials with permanent memory of deformation, providing an alternate, controlled route from liquid drops to elastic beads. The study unifies liquid and solid impact processes and offers a general framework for the liquid-to-elastic transition relevant across systems and applications. - oai:arXiv.org:2510.24855v2 - cond-mat.soft - physics.flu-dyn - Fri, 12 Dec 2025 00:00:00 -0500 - replace-cross - http://creativecommons.org/licenses/by/4.0/ - Saumili Jana, John Kolinski, Detlef Lohse, Vatsal Sanjay - - - High-impact Scientific Software in Astronomy and its creators - https://arxiv.org/abs/2511.12195 - arXiv:2511.12195v2 Announce Type: replace-cross -Abstract: In the last decades, scientific software has graduated from a hidden side-product to a first-class member of the astrophysics literature. We aim to quantify the activity and impact of software development for astronomy, using a systematic survey. Starting from the Astrophysics Source Code Library and the Journal of Open Source Software, we analyse 3432 public git-based scientific software packages. Paper abstract text analysis suggests seven dominant themes: cosmology, data reduction pipelines, exoplanets, hydrodynamic simulations, radiative transfer spectra simulation, statistical inference and galaxies. We present key individual software contributors, their affiliated institutes and countries of high-impact software in astronomy & astrophysics. We consider the number of citations to papers using the software and the number of person-days from their git repositories, as proxies for impact and complexity, respectively. We find that half of the mapped development is through US-affiliated institutes, and a large number of high-impact projects are led by a single person. Our results indicate that there are currently over 200 people active on any given day to improve software in astronomy. - oai:arXiv.org:2511.12195v2 - astro-ph.IM - physics.soc-ph - Fri, 12 Dec 2025 00:00:00 -0500 - replace-cross - http://creativecommons.org/licenses/by-nc-sa/4.0/ - 10.3847/25c2cfeb.fe9c1f84 - Bulletin of the AAS, 2025, Dec 11, Volume 57 - Johannes Buchner + 10.1364/OPTICAQ.569352 + Optica Quantum Vol. 3, Issue 6, pp. 606-616 (2025) + Jiapeng Zhao, Yang Xu, Xiyuan Lu, Eneet Kaur, Michael Kilzer, Ramana Kompella, Robert W. Boyd, Reza Nejabati - Enforcing hidden physics in physics-informed neural networks - https://arxiv.org/abs/2511.14348 - arXiv:2511.14348v2 Announce Type: replace-cross -Abstract: Physics-informed neural networks (PINNs) represent a new paradigm for solving partial differential equations (PDEs) by integrating physical laws into the learning process of neural networks. However, ensuring that such frameworks fully reflect the physical structure embedded in the governing equations remains an open challenge, particularly for maintaining robustness across diverse scientific problems. In this work, we address this issue by introducing a simple, generalized, yet robust irreversibility-regularized strategy that enforces hidden physical laws as soft constraints during training, thereby recovering the missing physics associated with irreversible processes in the conventional PINN. This approach ensures that the learned solutions consistently respect the intrinsic one-way nature of irreversible physical processes. Across a wide range of benchmarks spanning traveling wave propagation, steady combustion, ice melting, corrosion evolution, and crack growth, we observe substantial performance improvements over the conventional PINN, demonstrating that our regularization scheme reduces predictive errors by more than an order of magnitude, while requiring only minimal modification to existing PINN frameworks. - oai:arXiv.org:2511.14348v2 - cs.LG + Atomic structure of the PL5 defect in silicon carbide revealed by single-spin spectroscopy and oxygen implantation + https://arxiv.org/abs/2504.07558 + arXiv:2504.07558v2 Announce Type: replace-cross +Abstract: PL5 and PL6 centers in 4H-SiC are promising for quantum applications due to their superior charge stability and optically detected magnetic resonance (ODMR) properties at room temperature. However, their atomic structures remain unresolved, with ongoing controversy regarding their potential association with stacking faults. Previous measurements relying on spin ensemble detection were insufficient to draw definitive conclusions. In this work, we conduct correlative imaging of stacking faults and PL5/PL6 at the single-defect level, definitively ruling out any spatial correlation and demonstrating that these centers are not associated with stacking faults. Furthermore, we find that substituting oxygen for nitrogen in ion implantation enhances the yields of PL5 and PL6 by more than $11$-fold and $23$-fold, respectively. Single-spin ODMR spectroscopy of PL5 reveals six distinct orientations, determines the transverse zero-field splitting parameter $E$, and characterizes the hyperfine coupling. Combined with our ab initio calculations, these results provide compelling evidence for the assignment of PL5 as an OV($kh$) defect, consisting of an oxygen atom occupying the C($k$) site as the nearest neighbor to a Si($h$) vacancy. The structural analysis together with the demonstrated defect yield enhancement lays the foundation for fabricating high-sensitivity, high-contrast ensemble quantum sensors in two and three dimensions. + oai:arXiv.org:2504.07558v2 + cond-mat.mtrl-sci + cond-mat.mes-hall physics.comp-ph - Fri, 12 Dec 2025 00:00:00 -0500 - replace-cross - http://creativecommons.org/licenses/by-nc-nd/4.0/ - Nanxi Chen, Sifan Wang, Rujin Ma, Airong Chen, Chuanjie Cui - - - On the First Quantum Correction to the Second Virial Coefficient of a Generalized Lennard-Jones Fluid - https://arxiv.org/abs/2511.14399 - arXiv:2511.14399v2 Announce Type: replace-cross -Abstract: We derive an explicit analytic expression for the first quantum correction to the second virial coefficient of a $d$-dimensional fluid whose particles interact via the generalized Lennard-Jones $(2n,n)$ potential. By introducing an appropriate change of variable, the correction term is reduced to a single integral that can be evaluated in closed form in terms of parabolic cylinder or generalized Hermite functions. The resulting expression compactly incorporates both dimensionality and stiffness, providing direct access to the low- and high-temperature asymptotic regimes. In the special case of the standard Lennard-Jones fluid ($d=3$, $n=6$), the formula obtained is considerably more compact than previously reported representations based on hypergeometric functions. The knowledge of this correction allows us to determine the first quantum contribution to the Boyle temperature, whose dependence on dimensionality and stiffness is explicitly analyzed, and enables quantitative assessment of quantum effects in noble gases such as helium, neon, and argon. Moreover, the same methodology can be systematically extended to obtain higher-order quantum corrections. - oai:arXiv.org:2511.14399v2 - cond-mat.stat-mech - cond-mat.soft - physics.class-ph - Fri, 12 Dec 2025 00:00:00 -0500 + quant-ph + Fri, 19 Dec 2025 00:00:00 -0500 replace-cross http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - 10.3390/e27121251 - Entropy 27, 1251 (2025) - Daniel Parejo, Andr\'es Santos + Yu Chen, Qi Zhang, Mingzhe Liu, Junda Wu, Jinpeng Liu, Xin Zhao, Jingyang Zhou, Pei Yu, Shaochun Lin, Yuanhong Teng, Wancheng Yu, Ya Wang, Changkui Duan, Fazhan Shi - Composition-Dependent Properties of $\mathrm{Ce_{x}La_{0.95-x}Tb_{0.05}F_{3}}$ Nanopowders Tailored for X-Ray Photodynamic Therapy and Cathodoluminescence Imaging - https://arxiv.org/abs/2511.14500 - arXiv:2511.14500v2 Announce Type: replace-cross -Abstract: This study investigates the synthesis and luminescence behavior of $\mathrm{Ce_{x}La_{0.95-x}Tb_{0.05}F_{3}}$ nanoparticles with varying $\mathrm{Ce^{3+}}$ content. The materials were prepared via a wet chemical route and thermally annealed to improve crystallinity and reduce defects. Phase composition and structural parameters were examined by X-ray diffraction (XRD), while elemental composition was determined by X-ray fluorescence (XRF). Cathodoluminescence (CL) intensity mapping was used to evaluate emission uniformity and monitor the degradation of luminescence under electron beam exposure. Photoluminescence (PL) and radioluminescence (RL) spectroscopy confirmed energy transfer from $\mathrm{Ce^{3+}}$ to $\mathrm{Tb^{3+}}$ ions. Luminescence intensities were found to depend strongly on both Ce content and thermal treatment. The results contribute to the understanding of defect-related quenching mechanisms and are relevant for the design of rare-earth-based luminescent nanomaterials for biomedical applications. - oai:arXiv.org:2511.14500v2 + Electrical generation of surface plasmon polaritons in plasmonic heterostructures + https://arxiv.org/abs/2505.02358 + arXiv:2505.02358v2 Announce Type: replace-cross +Abstract: Surface plasmon polaritons (SPPs) can be understood as two-dimensional light confined to a conductor-dielectric interface via plasmonic excitations. While low-energy SPPs behave similarly to photons, higher-frequency SPPs resemble surface plasmons. Electrically generating mid-range SPPs is particularly challenging because it requires compensating for momentum mismatch, a process conventionally achieved through inelastic electron transport in nanostructures. Here, we theoretically demonstrate that electrical SPP generation is possible by directly coupling electron-hole dipoles to the quantized SPP field across an insulating spacer without accompanying electron transport. This approach can be realized in plasmonic van der Waals heterostructures composed of strongly-biased monolayer graphene as the emitter, few-layer hexagonal boron nitride as the spacer, and silver (or gold) as the plasmonic material. In this configuration, graphene's remarkable ability to support a strongly non-equilibrium steady-state electron-hole population results in non-thermal, bias-tunable SPP emission that is uniform along the hBN/Ag interface, achieving a power conversion efficiency of up to 1% and a Purcell factor of up to 100. These findings pave the way for integrating photonic and electronic functionalities within a single two-dimensional heterostructure. + oai:arXiv.org:2505.02358v2 + cond-mat.mes-hall cond-mat.mtrl-sci - physics.med-ph - Fri, 12 Dec 2025 00:00:00 -0500 + physics.optics + Fri, 19 Dec 2025 00:00:00 -0500 replace-cross - http://creativecommons.org/licenses/by-nc-nd/4.0/ - 10.1016/j.radmeas.2025.107536 - Xenie Lytvynenko, Marie Urbanov\'a, Ond\v{r}ej Lalinsk\'y, Vil\'em Vojta, Jan B\'arta, Lenka Prouzov\'a Proch\'azkov\'a, V\'aclav \v{C}uba + http://arxiv.org/licenses/nonexclusive-distrib/1.0/ + Maxim Trushin - Deformation and organization of droplet-encapsulated soft beads - https://arxiv.org/abs/2511.18002 - arXiv:2511.18002v2 Announce Type: replace-cross -Abstract: Many biological, culinary, and engineering processes lead to the co-encapsulation of several soft particles within a liquid interface. In these situations the particles are bound together by the capillary forces that deform them and influence their biological or rheological properties. Here we introduce an experimental approach to encapsulate a controlled number of soft beads within aqueous droplets in oil. These droplet-encapsulated gels are manipulated in a deformable microfluidic device to merge them and modify the liquid fraction. In the dry limit the contact surface between the hydrogels is found to be determined by the elastocapillary number $E_c$, with the contact radius scaling as $E_c^{1/3}$, indicating that the deformation increases for soft or small particles. When multiple beads are co-encapsulated within a single droplet they can be arranged into linear or three-dimensional aggregates that remain at a local energy minimum. - oai:arXiv.org:2511.18002v2 - cond-mat.soft + A new data-driven energy-stable Evolve-Filter-Relax model for turbulent flow simulation + https://arxiv.org/abs/2507.17423 + arXiv:2507.17423v2 Announce Type: replace-cross +Abstract: We present a novel approach to define the filter and relax steps in the evolve-filter-relax (EFR) framework for simulating turbulent flows. The EFR main advantages are its ease of implementation and computational efficiency. However, as it only contains two parameters (one for the filter step and one for the relax step) its flexibility is rather limited. In this work, we propose a data-driven approach in which the optimal filter is found based on DNS data in the frequency domain. The optimization step is computationally efficient and only involves one-dimensional least-squares problems for each wavenumber. Across both decaying turbulence and Kolmogorov flow, our learned filter decisively outperforms the standard differential filter and the Smagorinsky model, yielding significantly improved accuracy in energy spectra and in the temporal evolution of both energy and enstrophy. In addition, the relax parameter is determined by requiring energy and/or enstrophy conservation, which enforces stability of the method and reduces the appearance of numerical wiggles, especially when the filter is built in scarce data regimes. Applying the learned filter is also more computationally efficient compared to traditional differential filters, as it circumvents solving a linear system. + oai:arXiv.org:2507.17423v2 + math.NA + cs.NA physics.flu-dyn - Fri, 12 Dec 2025 00:00:00 -0500 - replace-cross - http://creativecommons.org/licenses/by-nc-sa/4.0/ - Shunsuke Saita, Finn Bastian Molzahn, Clara Delahousse, Julien Husson, Charles N. Baroud - - - Exciton spin structure in lead halide perovskite semiconductors explored via the spin dynamics in magnetic field - https://arxiv.org/abs/2512.02885 - arXiv:2512.02885v2 Announce Type: replace-cross -Abstract: We theoretically investigate the spin structure and spin dynamics of excitons in bulk lead halide perovskite semiconductors with cubic, tetragonal, and orthorhombic crystal symmetry. The exciton spin structure and its modification by an external magnetic field are modeled for different regimes defined by the relative magnitude of the electron-hole exchange interaction (splitting between dark and bright states) and the Zeeman spin splitting. The effects of crystal symmetry and magnetic field orientation with respect to the crystal axes are considered for lead halide perovskite crystals with band gaps in the range 1.4 - 3.5 eV, having different ratios of electron and hole g-factors. For cubic symmetry, in a longitudinal magnetic field, our theory predicts quantum beats between the bright exciton states under linearly polarized excitation and detection, while the dark exciton remains optically inactive. In a transverse magnetic field, all exciton spin states become optically active and can be excited by circularly polarized light. Reduction of the crystal symmetry leads to a zero-field offset of the exciton Larmor precession frequencies, modifying the Zeeman splitting energy dependence on magnetic field. This theoretical framework allows for the extraction of the strength of the exchange interaction and the crystal symmetry. Experimentally, we measure the exciton spin coherence via time-resolved photoluminescence at a temperature of 1.6 K in longitudinal and transverse magnetic fields in orthorhombic MAPbI3 crystals. Polarization beats at the frequency of the bright exciton are observed in both configurations. Comparison with theory indicates that the excitons are in the strong exchange interaction regime, and the reduction of symmetry does not lead to a significant splitting of the exciton spin levels. - oai:arXiv.org:2512.02885v2 - cond-mat.other - physics.optics - Fri, 12 Dec 2025 00:00:00 -0500 + Fri, 19 Dec 2025 00:00:00 -0500 replace-cross - http://creativecommons.org/licenses/by-nc-nd/4.0/ - Vladimir L. Zhiliakov, Nataliia E. Kopteva, Irina A. Yugova, Dmitri R. Yakovlev, Ilya A. Akimov, Manfred Bayer + http://arxiv.org/licenses/nonexclusive-distrib/1.0/ + 10.1016/j.cma.2025.118654 + Anna Ivagnes, Toby van Gastelen, Syver D{\o}ving Agdestein, Benjamin Sanderse, Giovanni Stabile, Gianluigi Rozza - Practical protein-pocket hydration-site prediction for drug discovery on a quantum computer - https://arxiv.org/abs/2512.08390 - arXiv:2512.08390v2 Announce Type: replace-cross -Abstract: Demonstrating the practical utility of Noisy Intermediate-Scale Quantum (NISQ) hardware for recurrent tasks in Computer-Aided Drug Discovery is of paramount importance. We tackle this challenge by performing three-dimensional protein pockets hydration-site prediction on a quantum computer. Formulating the water placement problem as a Quadratic Unconstrained Binary Optimization (QUBO), we use a hybrid approach coupling a classical three-dimensional reference-interaction site model (3D-RISM) to an efficient quantum optimization solver, to run various hardware experiments up to 123 qubits. Matching the precision of classical approaches, our results reproduced experimental predictions on real-life protein-ligand complexes. Furthermore, through a detailed resource estimation analysis, we show that accuracy can be systematically improved with increasing number of qubits, indicating that full quantum utility is in reach. Finally, we provide evidence that advantageous situations could be found for systems where classical optimization struggles to provide optimal solutions. The method has potential for assisting simulations of protein-ligand complexes for drug lead optimization and setup of docking calculations. - oai:arXiv.org:2512.08390v2 - quant-ph - physics.bio-ph - physics.chem-ph - Fri, 12 Dec 2025 00:00:00 -0500 + Entanglement across scales: Quantics tensor trains as a natural framework for renormalization + https://arxiv.org/abs/2507.19069 + arXiv:2507.19069v2 Announce Type: replace-cross +Abstract: Understanding entanglement remains one of the most intriguing problems in physics. While particle and site entanglement have been studied extensively, the investigation of length or energy scale entanglement, quantifying the information exchange between different length scales, has received far less attention. Here, we identify the quantics tensor train (QTT) technique, a matrix product state-inspired approach for overcoming computational bottlenecks in resource-intensive numerical calculations, as a renormalization group method by analytically expressing an exact cyclic reduction-based real-space renormalization scheme in QTT language, which serves as a natural formalism for the method. In doing so, we precisely match the QTT bond dimension, a measure of length scale entanglement, to the number of rescaled couplings generated in each coarse-graining renormalization step. While QTTs have so far been applied almost exclusively to numerical problems in physics, our analytical calculations demonstrate that they are also powerful tools for mitigating computational costs in semi-analytical treatments. We present our results for the one-dimensional tight-binding model with n-th-nearest-neighbor hopping, where the 2n rescaled couplings generated in the renormalization procedure precisely match the QTT bond dimension of the one-particle Green's function. + oai:arXiv.org:2507.19069v2 + cond-mat.str-el + math-ph + math.MP + physics.comp-ph + Fri, 19 Dec 2025 00:00:00 -0500 replace-cross http://creativecommons.org/licenses/by/4.0/ - Daniele Loco, Kisa Barkemeyer, Andre R. R. Carvalho, Jean-Philip Piquemal + 10.1103/qlrs-6f8t + Phys. Rev. Research 7, 043313 (2025) + Stefan Rohshap, Jheng-Wei Li, Alena Lorenz, Serap Hasil, Karsten Held, Anna Kauch, Markus Wallerberger - High-OAM Deep Ultraviolet Twisted Light Generation for RF-Photoinjector Applications - https://arxiv.org/abs/2512.08442 - arXiv:2512.08442v3 Announce Type: replace-cross -Abstract: We report on the generation and characterization of ultraviolet (wavelength 266 nm) twisted light with high orbital angular momentum (OAM) using three types of fabricated diffractive optical elements (DOEs): a reflective fork grating, a high-charge spiral phase plate (SPP), and binary axicons. All elements were integrated into a drive-laser beamline of an electron RF-photoinjector, enabling direct evaluation under accelerator-relevant conditions. The SPP produced a high-purity Laguerre-Gaussian mode with OAM l = 64 and a measured conversion efficiency of approximately 80%. Binary axicons generated quasi-Bessel twisted light with topological charges up to m = 10, exhibiting low divergence and stable multi-lobe ring structures. The fork grating reliably produced lower-order modes, l = 2-8, with good agreement between simulations and cylindrical-lens diagnostics. These results constitute, to our knowledge, the first comprehensive experimental demonstration of deep-UV high-OAM beams generated with fabricated DOEs and validated through mode-conversion measurements. The demonstrated techniques are compatible with high-power UV laser systems used in RF-photoinjectors and offer a practical route toward structured photocathode illumination and the generation of relativistic vortex electrons at a particle accelerator facility. - oai:arXiv.org:2512.08442v3 + Quantum Fisher information as a witness of non-Markovianity and criticality in the spin-boson model + https://arxiv.org/abs/2508.16413 + arXiv:2508.16413v3 Announce Type: replace-cross +Abstract: The quantum Fisher information, the quantum analogue of the classical Fisher information, is a central quantity in quantum metrology and quantum sensing due to its connection to parameter estimation and fidelity susceptibility. Using numerically exact methods applied to a paradigmatic open quantum system, the spin-boson model, we calculate both static and dynamical quantum Fisher information matrix elements with respect to spin-bath couplings and magnetic field strengths. As the spin-bath interaction increases, we first show that the coupling-coupling matrix elements relative to the ground state of the Hamiltonian are linked to the entanglement growth and signal the Berezinskii-Kosterlitz-Thouless quantum phase transition through their non-monotonic behavior. We also point out that the static quantum Fisher information exhibits a non-perturbative behavior in the zero-coupling limit, which we justify with an analytic argument. Furthermore, we demonstrate that the time-dependent matrix elements can reveal non-Markovian effects as well as the transition from the coherent to incoherent regime at the Toulouse point, remaining robust under pure dephasing noise. Non-monotonic signatures of the quantum Fisher information matrix reflect changes in quantum resources such as entanglement and coherence, quantify non-Markovian behavior, and enable criticality-enhanced quantum sensing, thereby shedding light on key features of open quantum systems. + oai:arXiv.org:2508.16413v3 quant-ph - physics.acc-ph - physics.optics - Fri, 12 Dec 2025 00:00:00 -0500 - replace-cross - http://creativecommons.org/licenses/by/4.0/ - A. S. Dyatlov, D. M. Dolgintsev, V. V. Gerasimov, V. V. Kobets, V. P. Nazmov, M. A. Nozdrin, A. N. Sergeev, D. S. Shokin, K. E. Yunenko, D. V. Karlovets - - - Many interacting particles in solution. II. Screening-ranged expansion of electrostatic forces - https://arxiv.org/abs/2512.08682 - arXiv:2512.08682v2 Announce Type: replace-cross -Abstract: We present a fully analytical integration of the Maxwell stress tensor and derive exact relations for interparticle forces in systems of multiple dielectric spheres immersed in a polarizable ionic solvent, within the framework of the linearized Poisson--Boltzmann theory. Building upon the screening-ranged (in ascending orders of Debye screening) expansions of the potentials developed and rigorously analyzed in the accompanying works arXiv:2512.08407, arXiv:2512.08684, arXiv:2512.09421, we construct exact screening-ranged many-body expansions for electrostatic forces in explicit analytical form. These results establish a rigorous foundation for evaluating screened electrostatic interactions in complex particle systems and provide direct analytical connections to, and systematic improvements upon, various earlier approximate or limited-case formulations available in the literature, both at zero and finite ionic strength. - oai:arXiv.org:2512.08682v2 - cond-mat.soft - math-ph - math.MP - physics.bio-ph - physics.chem-ph + cond-mat.stat-mech physics.comp-ph - Fri, 12 Dec 2025 00:00:00 -0500 + Fri, 19 Dec 2025 00:00:00 -0500 replace-cross - http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Sergii V. Siryk, Walter Rocchia + http://creativecommons.org/licenses/by/4.0/ + 10.1103/fq4l-8v5g + Phys. Rev. B 112, 224314 (2025) + Daniele Parlato, Grazia Di Bello, Fabrizio Pavan, Giulio De Filippis, Carmine Antonio Perroni - Many interacting particles in solution. III. Spectral analysis of the associated Neumann--Poincar\'e-type operators - https://arxiv.org/abs/2512.08684 - arXiv:2512.08684v2 Announce Type: replace-cross -Abstract: The interaction of particles in an electrolytic medium can be calculated by solving the Poisson equation inside the solutes and the linearized Poisson--Boltzmann equation in the solvent, with suitable boundary conditions at the interfaces. Analytical approaches often expand the potentials in spherical harmonics, relating interior and exterior coefficients and eliminating some coefficients in favor of others, but a rigorous spectral analysis of the corresponding formulations is still lacking. Here, we introduce pertinent composite many-body Neumann--Poincar\'e-type operators and prove that they are compact with spectral radii strictly less than one. These results provide the foundation for systematic screening-ranged expansions, in powers of the Debye screening parameters, of electrostatic potentials, interaction energies, and forces, and establish the analytical framework for the accompanying works arXiv:2512.09421, arXiv:2512.08407, arXiv:2512.08682. - oai:arXiv.org:2512.08684v2 + Phase field modelling of the growth and detachment of bubbles in a hydrogen electrolyzer + https://arxiv.org/abs/2508.16585 + arXiv:2508.16585v3 Announce Type: replace-cross +Abstract: We develop and implement numerically a phase field model for the growth and detachment of a gas bubble resting on an electrode and being filled with hydrogen produced by water electrolysis. The bubble is surrounded by a viscous liquid, has a prescribed static contact angle and is also subject to gravitational forces. We compute, as a function of the static contact angle, the time at which the bubble detaches from the substrate and what volume it has at that time. We also investigate de dependence of the detachment time on other parameters such as the applied voltage and the hydrogen ion concentration at the fluid bulk. + oai:arXiv.org:2508.16585v3 cond-mat.soft - math-ph - math.MP - physics.bio-ph - physics.chem-ph - physics.comp-ph - Fri, 12 Dec 2025 00:00:00 -0500 + cond-mat.mtrl-sci + physics.flu-dyn + Fri, 19 Dec 2025 00:00:00 -0500 replace-cross http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Sergii V. Siryk, Walter Rocchia + Carlos Uriarte, Marco A. Fontelos, Manuel Array\'as - GEARS - A Fully Run-Time Configurable Geant4 Application - https://arxiv.org/abs/2512.09246 - arXiv:2512.09246v2 Announce Type: replace-cross -Abstract: The Geant4 toolkit is the standard for simulating the passage of particles through matter, but its conventional architecture often requires users to modify and recompile C++ code to alter fundamental simulation parameters such as geometry, physics list, and primary particle source. This architectural constraint introduces significant friction for new users and slows down the experimental iteration cycle. This paper introduces GEARS (Geant4 Example Application with Rich features yet Small footprint), a universally applicable Geant4 application that fundamentally addresses this issue. GEARS achieves complete simulation configurability without C++ recompilation by strictly utilizing external configuration methods: Geometry is defined via simple text-based configuration, the Physics List is selected via the standard PHYSLIST environment variable, and the Primary Source is defined through the General Particle Source (GPS) macro commands. Furthermore, regarding GEARS as an application instead of a framework, key features include a flat ntuple structure with short variable names for highly efficient analysis and a solution for capturing vital initial step data. Output creation is also fully managed via run-time macro commands and volume properties. The project is distributed as a ready-to-use Docker container to eliminate compilation barriers. Through these design considerations, GEARS transforms Geant4 into a practical, ready-to-use tool, enabling users to rapidly prototype and execute simulations for diverse experiments solely through simple text configuration files, without ever needing to modify or compile the underlying C++ source code. - oai:arXiv.org:2512.09246v2 - hep-ex + Direct probing of the simulation complexity of open quantum many-body dynamics + https://arxiv.org/abs/2508.19959 + arXiv:2508.19959v2 Announce Type: replace-cross +Abstract: Simulating open quantum systems is key to understanding non-equilibrium processes, as persistent influence from the environment induces dissipation and can give rise to steady-state phase transitions. A common strategy is to embed the system-environment into a larger unitary framework, but this obscures the intrinsic complexity of the reduced system dynamics. Here, we investigate the computational complexity of simulating open quantum systems, focusing on two physically relevant parameters -- correlation length and mixing time -- and explore whether it can be comparable (or even lower) to that of simulating their closed counterparts. In particular, we study the role of dissipation in simulating open-system dynamics using both quantum and classical methods, where the classical complexity is characterised by the bond dimension and operator entanglement entropy. Our results show that dissipation affects correlation length and mixing time in distinct ways at intermediate and long timescales. Moreover, we observe numerically that in classical tensor network simulations, classical complexity does not decrease with stronger dissipation, revealing a separation between quantum and classical resource scaling. + oai:arXiv.org:2508.19959v2 + quant-ph physics.comp-ph - Fri, 12 Dec 2025 00:00:00 -0500 + Fri, 19 Dec 2025 00:00:00 -0500 replace-cross - http://creativecommons.org/licenses/by-nc-nd/4.0/ - Jing Liu + http://creativecommons.org/licenses/by/4.0/ + Lucia Vilchez-Estevez, Alexander Yosifov, Jinzhao Sun - Meta-learning three-factor plasticity rules for structured credit assignment with sparse feedback - https://arxiv.org/abs/2512.09366 - arXiv:2512.09366v2 Announce Type: replace-cross -Abstract: Biological neural networks learn complex behaviors from sparse, delayed feedback using local synaptic plasticity, yet the mechanisms enabling structured credit assignment remain elusive. In contrast, artificial recurrent networks solving similar tasks typically rely on biologically implausible global learning rules or hand-crafted local updates. The space of local plasticity rules capable of supporting learning from delayed reinforcement remains largely unexplored. Here, we present a meta-learning framework that discovers local learning rules for structured credit assignment in recurrent networks trained with sparse feedback. Our approach interleaves local neo-Hebbian-like updates during task execution with an outer loop that optimizes plasticity parameters via \textbf{tangent-propagation through learning}. The resulting three-factor learning rules enable long-timescale credit assignment using only local information and delayed rewards, offering new insights into biologically grounded mechanisms for learning in recurrent circuits. - oai:arXiv.org:2512.09366v2 - q-bio.NC - cond-mat.dis-nn + TACE: A unified Irreducible Cartesian Tensor Framework for Atomistic Machine Learning + https://arxiv.org/abs/2509.14961 + arXiv:2509.14961v2 Announce Type: replace-cross +Abstract: Here, we introduce the Tensor Atomic Cluster Expansion (TACE), a unified framework formulated entirely in Cartesian space, enabling systematic and consistent prediction of arbitrary structure-dependent tensorial properties. TACE achieves this by decomposing atomic environments into a complete hierarchy of irreducible Cartesian tensors, ensuring symmetry-consistent representations that naturally encode invariance and equivariance constraints. Beyond geometry, TACE incorporates universal embeddings that flexibly integrate diverse attributes including computational levels, charges, magnetic moments and field perturbations. This allows explicit control over external invariants and equivariants in the prediction process. Long-range interactions are also accurately described through the Latent Ewald Summation module within the short-range approximation, providing a rigorous yet computationally efficient treatment of electrostatic and dispersion effects. We demonstrate that TACE attains accuracy, stability, and efficiency on par with or surpassing leading equivariant frameworks across finite molecules and extended materials. This includes in-domain and out-of-domain benchmarks, spectra, Hessian, external-field responses, charged and magnetic systems, multi-fidelity training, heterogeneous catalysis, and even superior performance within the uMLIP benchmark. Crucially, TACE bridges scalar and tensorial modeling and establishes a Cartesian-space paradigm that unifies and extends beyond the design space of spherical-tensor-based methods. This work lays the foundation for a new generation of universal atomistic machine learning models capable of systematically capturing the rich interplay of geometry, fields and material properties within a single coherent framework. + oai:arXiv.org:2509.14961v2 + stat.ML + cond-mat.mtrl-sci cs.LG - physics.bio-ph - Fri, 12 Dec 2025 00:00:00 -0500 + physics.chem-ph + Fri, 19 Dec 2025 00:00:00 -0500 replace-cross - http://creativecommons.org/licenses/by-nc-nd/4.0/ - Dimitra Maoutsa + http://creativecommons.org/licenses/by-nc-sa/4.0/ + Zemin Xu, Wenbo Xie, Daiqian Xie, P. Hu - Exact Screening-Ranged Expansions for Many-Body Electrostatics - https://arxiv.org/abs/2512.09421 - arXiv:2512.09421v2 Announce Type: replace-cross -Abstract: We present an exact many-body framework for electrostatic interactions among $N$ arbitrarily charged spheres in an electrolyte, modeled by the linearized Poisson--Boltzmann equation. Building on a spectral analysis of nonstandard Neumann--Poincar\'e-type operators introduced in a companion mathematical work arXiv:2512.08684, we construct convergent screening-ranged series for the potential, interaction energy, and forces, where each term is associated with a well-defined Debye--H\"uckel screening order and can be obtained evaluating an analytical expression rather than numerically solving an infinitely dimensional linear system. This formulation unifies and extends classical and recent approaches, providing a rigorous basis for electrostatic interactions among heterogeneously charged particles (including Janus colloids) and yielding many-body generalizations of analytical explicit-form results previously available only for two-body systems. The framework captures and clarifies complex effects such as asymmetric dielectric screening, opposite-charge repulsion, and like-charge attraction, which remain largely analytically elusive in existing treatments. Beyond its fundamental significance, the method leads to numerically efficient schemes, offering a versatile tool for modeling colloids and soft/biological matter in electrolytic solution. - oai:arXiv.org:2512.09421v2 - cond-mat.soft - math-ph - math.MP - physics.bio-ph - physics.chem-ph - physics.comp-ph - Fri, 12 Dec 2025 00:00:00 -0500 + Spectrometry of Captured Highly Charged Ions Produced Following Antiproton Annihilations + https://arxiv.org/abs/2510.08440 + arXiv:2510.08440v2 Announce Type: replace-cross +Abstract: We report a proof-of-principle study demonstrating the first capture and time-of-flight spectrometry of highly charged ions (HCIs) produced following antiproton annihilations in a Penning-Malmberg trap. A multi-step nested-trap technique was developed using the \aegis\ experiment to identify annihilation-linked captured ions. The trapping and spectrometry of helium and argon ions demonstrates the approach. This work establishes a foundation for the in-trap synthesis of radioactive HCIs and the study of cold nuclear annihilation fragments, with the long-term goal of enabling a sensitive tool for probing the outer nuclear periphery. + oai:arXiv.org:2510.08440v2 + nucl-ex + physics.atom-ph + Fri, 19 Dec 2025 00:00:00 -0500 replace-cross - http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Sergii V. Siryk, Walter Rocchia + http://creativecommons.org/licenses/by-nc-nd/4.0/ + F. P. Gustafsson, M. Volponi, J. Zielinski, A. Asare, I. Hwang, S. Alfaro Campos, M. Auzins, D. Bhanushali, A. Bhartia, M. Berghold, R. S. Brusa, K. Calik, A. Camper, R. Caravita, F. Castelli, G. Cerchiari, S. Chandran, A. Chehaimi, S. Choudapurkar, R. Ciury{\l}o, P. Conte, G. Consolati, M. Doser, R. Ferguson, M. Germann, A. Giszczak, L. T. Gl\"oggler, {\L}. Graczykowski, M. Grosbart, F. Guatieri, N. Gusakova, S. Haider, S. Huck, C. Hugenschmidt, M. Jakubowska, M. A. Janik, G. Kasprowicz, K. Kempny, G. Khatri, A. Kisiel, {\L}. K{\l}osowski, G. Kornakov, V. Krumins, L. Lappo, A. Linek, S. Mariazzi, P. Moskal, M. M\"unster, P. Pandey, L. Penasa, M. Piwi\'nski, F. Prelz, T. Rauschendorfer, B. S. Rawat, B. Rien\"acker, V. Rodin, H. Sandaker, S. Sharma, T. Sowi\'nski, E. T\=eberga, M. Tockner, C. P. Welsch, M. Zawada, N. Zurlo - Linear and Nonlinear Optical Properties of SiO$_2$/TiO$_2$ Heterostructures Grown by Plasma Enhanced Atomic Layer Deposition - https://arxiv.org/abs/2512.09819 - arXiv:2512.09819v2 Announce Type: replace-cross -Abstract: Second harmonic (SH) radiation can only be generated in non-centrosymmetric bulk crystals under the electric-dipole approximation. Nonlinear thin films made from bulk crystals are technologically challenging because of complex and high temperature fabrication processes. In this work, heterostructures made of amorphous materials SiO$_2$ and TiO$_2$ were prepared by a CMOS-compatible technique named plasma enhanced atomic layer deposition (PEALD) with deposition temperature at 100 {\deg}C. By using the uniaxial dispersion model, we characterized the form-birefringence properties, which can enable the phase matching condition in waveguides or other nonlinear optical applications. By applying a fringe-based technique, we determined the largest diagonal component of the effective second-order bulk susceptibility $\chi_{zzz}^{(2)}$ = 1.30$\pm$0.13 pm/V at a wavelength of 1032 nm. Noteworthy, we observed strong SH signals from two-component nanolaminates, which are several orders of magnitude larger than from single layers. The SH signals from our samples only require the broken inversion symmetry at the interface. Here optical properties of nanocomposites can be precisely tuned by the promising PEALD technology. - oai:arXiv.org:2512.09819v2 + Multiphase transport and compositional mixing mechanisms in twin-wire laser directed energy deposition: toward process stability and graded material fabrication + https://arxiv.org/abs/2511.13142 + arXiv:2511.13142v2 Announce Type: replace-cross +Abstract: Twin-wire laser directed energy deposition (TW-LDED) provides a promising route for alloying and fabrication of compositionally graded structures. However, inherent multiparameter coupling in twin-wire systems critically exacerbates both process instabilities and compositional inhomogeneity. This unresolved issue escalates into a fundamental technological bottleneck, as the underlying physical mechanisms remain poorly understood. This study developed a high-fidelity multi-physics and multiphase simulation framework coupled with experimental validation to reveal thermal-fluid behavior and heat-mass transfer mechanisms in TW-LDED using Inconel 718 and SS316L fine wires. Three distinct transition modes were identified: twin-wire melt droplet, twin-wire liquid bridge, and droplet-bridge mixed transitions, with the twin-wire liquid bridge regime delivering optimal stability and uniform mixing. Parametric analysis demonstrates that increasing wire feeding speed or decreasing wire initial height promotes stable liquid bridge formation, while small laser spots at low feeding speeds induce excessive volumetric energy density and bridge instability. Simulation and single-track experiments confirm that liquid bridge transitions reduce dimensional fluctuations by 85% while enhancing compositional homogeneity. Conversely, the melt droplet-bridge transition mode creates periodic flow switching and compositional discontinuities along the scan direction. Finally, a 60 mm functionally graded ring was successfully fabricated using optimized parameters, achieving uniform elemental distribution in the transition zone without significant segregation, validating the feasibility of TW-LDED for functionally graded components. + oai:arXiv.org:2511.13142v2 + nlin.CD cond-mat.mtrl-sci - physics.app-ph - Fri, 12 Dec 2025 00:00:00 -0500 + physics.flu-dyn + Fri, 19 Dec 2025 00:00:00 -0500 replace-cross - http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Jinsong Liu, Martin Mi\v{c}ulka, Raihan Rafi, Sebastian Beer, Denys Sevriukov, Stefan Nolte, Sven Schr\"oder, Andreas T\"unnermann, Isabelle Staude, Adriana Szeghalmi + http://creativecommons.org/licenses/by/4.0/ + Yi Li, Yuhui Li, Jianzhao Wu, Luxuan Zhang, Maoyuan Li, Chaochao Wu, Zhenzhong Wang - Programmable Assembly of Ground State Fermionic Tweezer Arrays - https://arxiv.org/abs/2512.09849 - arXiv:2512.09849v2 Announce Type: replace-cross -Abstract: We demonstrate deterministic preparation of arbitrary two-component product states of fermionic $^6$Li atoms in an 8$\times$8 optical tweezer array, achieving motional ground-state fidelities above $98.5\,\%$. Leveraging the large differential magnetic moments for spin-resolution, with parallelized site- and number-resolved control, our approach addresses key challenges for low-entropy quantum state engineering. Combined with high-fidelity spin-, site-, and density-resolved readout within a single $20\,\mathrm{\mu s}$ exposure, and $3\,\mathrm{s}$ experimental cycles, these advances establish a fast, scalable, and programmable architecture for fermionic quantum simulation. - oai:arXiv.org:2512.09849v2 - cond-mat.quant-gas - physics.atom-ph - quant-ph - Fri, 12 Dec 2025 00:00:00 -0500 + Resummed Distribution Functions: Making Perturbation Theory Positive and Normalized + https://arxiv.org/abs/2512.04160 + arXiv:2512.04160v2 Announce Type: replace-cross +Abstract: Fixed-order perturbative calculations for differential cross sections can suffer from non-physical artifacts: they can be non-positive, non-normalizable, and non-finite, none of which occur in experimental measurements. We propose a framework, the Resummed Distribution Function (RDF), that, given a perturbative calculation for an observable to some finite order in $\alpha_s$, will ``resum'' the expression in a way that is guaranteed to match the original expression order-by-order and be positive, normalized, and finite. Moreover, our ansatz parameterizes all possible finite, positive, and normalized completions consistent with the original fixed-order expression, which can include N$^n$LL resummed expressions. The RDF also enables a more direct notion of perturbative uncertainties, as we can directly vary higher-order parameters and treat them as nuisance parameters. We demonstrate the power of the RDF ansatz by matching to thrust to $\mathcal{O}(\alpha_s^3)$ and extracting $\alpha_s$ with perturbative uncertainties by fitting the RDF to ALEPH data. + oai:arXiv.org:2512.04160v2 + hep-ph + hep-ex + physics.data-an + Fri, 19 Dec 2025 00:00:00 -0500 replace-cross http://creativecommons.org/licenses/by/4.0/ - Naman Jain, Jin Zhang, Marcus Culemann, Philipp M. Preiss + Rikab Gambhir, Radha Mastandrea