Mathematical Physics
Heat Kernel and Resurgence
Si Li, Yong Li and Xinxing Tang
We study the resurgent structure of short–time heat kernel asymptotics from the viewpoint of Picard–Lefschetz theory. For a real analytic Riemannian
manifold, we show the heat kernel admits a 1– Gevrey small–time expansion whose Borel transform detects complex–
geometric data beyond the real geodesic sector. We formulate an infinite–dimensional Picard–Lefschetz problem of Morse–Floer type for the holomorphic energy functional on the complexified path space, and propose a heat–kernel analogue of the Picard–Lefschetz/Alien correspondence. In this framework, pointed alien operators acting on the asymptotic expansion associated with the real geodesic are predicted to produce the formal heat–kernel sectors associated with other holomorphic geodesics, with coefficients given by signed counts of connecting trajectories of the Morse flow. We perform a confirming test of this proposal on the
hyperbolic plane $\mathbb{H}_{\R}^2$.
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Optics
Per-Span Microwave Frequency Fiber Interferometry in Subsea Cables for Scalable Deep-Ocean Geophysical Monitoring
Georgios Aias Karydis, Nicolas L. Celli, David Craig et al. (+6 more)
We demonstrate low-cost microwave frequency fibre interferometry for per-span monitoring of a 1,770 km operational subsea cable connecting Ireland and Iceland. Over four months, this approach successfully resolved
tidal variations, storms, and teleseismic earthquakes, highlighting its potential for large-scale, cost-effective ocean monitoring.
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All authors Georgios Aias Karydis, Nicolas L. Celli, David Craig, Örn Jónsson, Andrés Arnar Hlynsson, Eoin Kenny, Charis Mesaritakis, Christopher J. Bean, Adonis Bogris
Statistical Mechanics
Nonlocal fractional Kardar-Parisi-Zhang dynamics of grain boundaries
Kai Zhao
The kinetic roughening of driven grain boundaries (GBs) is mediated by the collective behavior of disconnections, whose long-range 1/r elastic interactions distinguish them from conventional growing surfaces. Large-scale molecular dynamics simulations show that the roughness of driven GBs undergoes a sharp crossover as the applied strain increases, with the Hurst exponent (H) increasing from approximately 0.33 to 0.8. We develop a nonlocal fractional Kardar-Parisi-Zhang (fKPZ) theory to describe this low-temperature behavior, where the 1/r nonlocal elasticity behaves as the fractional relaxation of the GB morphology. The results show that the spatially-correlated noise associated with disconnection avalanches interacts with the KPZ nonlinearity to produce the post-crossover roughening observed in atomistic simulations. The post-crossover roughness exponent (H ~ 0.8) is comparable to values reported for dynamic fracture, suggesting the underlying physics shared by the collective behavior of defects (e.g., disconnections, dislocations) and interfacial roughening.
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General Relativity and Quantum Cosmology
Entanglement, Discord, and Residual Coherence in Scalar-Induced Gravitational Waves
Waqas Ahmed
Scalar-induced gravitational waves (SIGWs) are usually characterized by their power spectrum, although their quadratic scalar source also carries higher-order correlation information. We investigate whether phase-sensitive correlations of a
primordial Gaussian scalar state can survive decoherence and be transferred to the induced tensor sector. The scalar state is described in a fixed oscillator basis by the occupation $N_k^\zeta$ and anomalous moment $M_k^\zeta$, while the transfer is formulated through the unequal-time scalar Wightman function. The late-time tensor moments $d_k$ and $\gamma_k$ define an effective Gaussian reference state and its discord, whereas the exact SIGW state is generally non-Gaussian and contains an additional connected fourth-order cumulant. We therefore introduce the baseline-subtracted observable $\Delta\kappa_{\rm coh}=\kappa_N[G^>_{\rm coh}]-\kappa_N[G^>_{\rm ref}]$. For phase damping with $M_k^\zeta\propto e^{-D_k}$, the Gaussian-reference contribution conditionally scales as $|\gamma_k|\propto e^{-2D_k}$ and $\kappa_N^{\rm G}\propto e^{-4D_k}$. This provides a framework in which the SIGW spectrum fixes the signal band, while higher-order statistics probe residual coherence beyond the power spectrum.
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Quantum Physics
Shuttling in Bidimensional Segmented Ion-Trap Quantum Processors with T-Junctions
J.Durandau, C.A. Brunet, F.Schmidt-Kaler et al. (+3 more)
Shuttle-based trapped ion
quantum processors typically employ a one-dimensional (1D) linear architecture to transport ion-
qubits between one ore more
laser interaction zones where the
quantum gates are implemented, along with several
qubit register storage segments. The two-dimensional (2D)
quantum CCD architecture employs also T- or X-junctions for an improved scaling and efficiency. Here, we explore the shuttling layer in the compilation of
quantum algorithm typical building blocks in such architecture. To weight the effort of linear shuttle and junction shuttle, we introduce individual cost functions for each operation. This allows comparing the total cost for
quantum circuit building blocks such as the QFT, Carry, Adder, Shift, and Comparator
circuits. We study their scaling properties with increased
qubit numbers. At equivalent transport cost for junction and linear shuttling, we show that 2D architectures outperform the 1D linear trap with the ratio improving as the number of ions increases. Finally, we discuss the use of
cells, such that the entire processor is constructed from a 2D array of such interconnected
cells. The work aims to optimize
quantum processor architectures, implementing a co-design that fits to the specific task and scaling up in a shuttle-efficient way.
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All authors J.Durandau, C.A. Brunet, F.Schmidt-Kaler, U.Poschinger, F.Mailhot, Y. Bérubé-Lauzière
Solar and Stellar Astrophysics
Prediction of Solar Flares Using Photospheric Magnetic Field Parameters with Deep Learning
Yash Chaudhary, Jason T. L. Wang, Chunhui Xu et al. (+2 more)
Solar flares, particularly those of the M- and X-class, have a significant impact on human life because of their potential to disrupt critical infrastructure and communication systems on Earth. Accurate prediction of
solar flares is crucial for mitigating these risks, but the black-box nature of conventional deep learning models used in
flare prediction limits their trustworthiness and interpretability. In this paper, we propose a new approach to
solar flare prediction using photospheric
magnetic field parameters or features with deep learning. To improve model interpretability, we integrate explainable artificial intelligence (XAI) techniques, including SHapley Additive exPlanations (SHAP) and partial dependence plots (PDPs), into our prediction framework. XAI methods provide transparency by analyzing the importance and interactions of features used by our model. Specifically, SHAP values offer a global and local understanding of the features, while PDPs provide insights into feature-level trends. These techniques demonstrate the potential of XAI in deploying AI-driven solutions in high-impact applications such as
solar flare prediction, paving the way for more informed decision-making in
solar physics and space weather studies.
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All authors Yash Chaudhary, Jason T. L. Wang, Chunhui Xu, Yan Xu, Sen Zhang
Applied Physics
Revisiting Theoretical Modeling of Seebeck Coefficient of Semiconductors
Yuchao Hua
We revisit the closed-form models of Seebeck coefficient, and identify the thermodynamic flaws in those extensively-used methodologies, essentially including the confusion of electrochemical potential and electrical potential within the definition, arbitrarily neglecting the dependence on conduction band bottom and
Fermi level when calculating distribution function spatial gradient, and the improper heat flux presentation. Here, an alternative methodology is presented, which derives the Seebeck coefficient model based on the drift-
diffusion equation with the Soret effect in the open
circuit condition. The reversible model that eliminates the electron velocity and relaxation terms in the formulation is recovered for the band term in the near-
equilibrium case, and it can give the lower bound of Seebeck coefficient in theory, while the
phonon-drag term is of the identical form to the Boltzmann transport equation(BTE)-based one. A case study is performed for highly-n-doped Silicon, where the reversible, ballistic(based on Landauer formulation) and BTE models are compared with each other and with the experimental data. The reversible model gives the fairly-good predictions for the experiments. Given its theoretical-soundness, simple form and low computation cost, the reversible model can serve as a concise alternative for evaluating thermoelectric properties in both the reversible and near-
equilibrium cases.
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Solar and Stellar Astrophysics
The efficiency per free-fall time as a ratio of the Star Formation Rate to the gas-infall rate in collapsing cores: dependence on the core definition, accretion, and radial structure
Fabián Quesada-Zúñiga, Manuel Zamora-Avilés, Enrique Vázquez-Semadeni et al. (+3 more)
A parameter used to characterise
star formation activity in MCs is the efficiency per free-fall time, $\epsilon_{\rm ff}$, although commonly referred to as an efficiency, it is formally the ratio between the
star formation rate (SFR) and the gas-infall rate. Here we numerically study the collapse of cores and define $\epsilon_{\rm ff}\equiv\langle\dot{M}_\star\rangle/(M_{\rm core}/\tau_{\rm ff})$, where $\langle\dot{M}_\star\rangle$ is the average SFR, $M_{\rm core}$ is the gas mass within the core (as the gas
cells above a density threshold), and $\tau_{\rm ff}$ is the free-fall time of the core gas. We perform simplified numerical experiments of the gravitational collapse of an isolated core, varying the initial mean number density ($n_0=100$ and $1000~\rm cm^{-3}$) and adopting closed/open BCs to (dis)allow fresh gas
accretion into the domain. The simulations start with a slight central Gaussian overdensity that evolved into a power-law profile, $n\propto r^{-p}$ with $p\to2$. As the collapse proceeds, a sink particle forms in the center of the core. We find that both the BCs and the adopted core definition modify the measured core properties and, consequently, the inferred $\epsilon_{\rm ff}$. Low-density models have less mass available, and their
accretion histories are therefore much more sensitive to the choice of BCs, while high-density runs, with their larger mass reservoirs, maintain similar
accretion histories regardless of the BCs. In all models, after sink formation, $\epsilon_{\rm ff}$ rises and then remains relatively stable while
accretion continues to replenish the core's mass, but increases once the gas reservoir is exhausted. Somewhat counterintuitively, $\epsilon_{\rm ff}$ is higher in the low-mass cores, since the larger gas infall rates onto the high-mass cores compensate for their higher SFR. We conclude that the inferred $\epsilon_{\rm ff}$ depends sensitively on both the adopted core definition and external mass supply
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All authors Fabián Quesada-Zúñiga, Manuel Zamora-Avilés, Enrique Vázquez-Semadeni, Gilberto C. Gómez, Aina Palau, Javier Ballesteros-Paredes
Quantum Physics
Demonstration of a Monolithic and Fully Telecom-Fiber-Compatible Tunable Source of Polarization Entangled Photon Pairs Based on a van der Waals Material
Benjamin Laudert, Fatemeh Abtahi, Duk Choi et al. (+2 more)
We present a tunable, single-mode-optical-fiber-based source of polarization entangled
photon pairs for the near-infrared telecommunication band that is deployable in standard infrastructure. The
photon pairs are generated via spontaneous parametric down-conversion (SPDC) in a submicron-scale thin film of the inversion-broken rhombohedral polytype of the transition metal dichalcogenide molybdenum disulfide (3R-MoS$_2$), located between two fiber connectors. By exploiting the intrinsic
symmetries of the second-order nonlinear susceptibility tensor of 3R-MoS$_2$, this hybrid approach offers control over the generated two-
photon polarization state through the incident pump polarization. Most notably, two of the four maximally entangled Bell states, as well as fully co-polarized pairs can be produced. This represents a substantial improvement in terms of tunability and simplicity over established fiber-integrated sources, which require additional optical elements, precise
alignment, or careful engineering of design parameters. Additionally, a nonlinear drop in the background photoluminescence signal of 3R-MoS$_2$ is observed at low pump powers, allowing us to reach a coincidences-to-accidentals ratio (CAR) of $(8.3\pm1.8)\times10^{3}$, the highest value recorded for SPDC in van der Waals materials to date.
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All authors Benjamin Laudert, Fatemeh Abtahi, Duk Choi, Dragomir Neshev, Falk Eilenberger
Strongly Correlated Electrons
Spectroscopic fingerprints of a ferroaxial charge density wave
Jiangchang Zheng, Zhongyi Zhang, Fazhi Yang et al. (+11 more)
Unconventional charge density waves (CDWs) with complex order parameters can host exotic collective modes and non-trivial
topologies. They have emerged as a new frontier in the study of
quantum matter. Recent experiments on rare-earth tritellurides have reported evidence for a ferroaxial CDW through the detection of characteristic Raman modes. This phase, often regarded as a hidden order, has been recognized to arise from the coupling between charge and orbital degrees of freedom in these materials. Yet, spectroscopic insight into its underlying electronic structure and the explicit form of its order parameter
symmetry has remained elusive. Here, we present results from linearly polarized angle-resolved photoemission spectroscopy (ARPES) and scanning tunneling microscopy (STM) measurements of the CDW phase in LaTe$_3$. Our ARPES measurements reveal a complex landscape of spectral gaps across the reconstructed
Fermi surface, while our STM-based quasiparticle interference (QPI) mapping, enhanced through the selective deposition of atomic scattering centers, directly reveals an inter-orbital CDW with mixed $p_x$-$p_z$ orbital character. The detailed analysis of the QPI characteristics in terms of the order parameter
symmetry within the orbital subspace of the
Fermi surface suggests a mixed CDW phase with substantial ferroaxial component, which breaks all vertical mirror
symmetries. More broadly, our work establishes a powerful spectroscopic pathway, based on scattering off individual atoms, for identifying and characterizing hidden, multi-component electronic orders in
quantum materials using STM and ARPES measurements.
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All authors Jiangchang Zheng, Zhongyi Zhang, Fazhi Yang, Josh Leeman, Luanjing Li, Zihan Lin, Zijian Fei, Tianhao Guo, Siyu Heng, Xin Liang, Leslie M. Schoop, Junzhang Ma, Hoi Chun Po, Berthold Jäck
Cosmology and Nongalactic Astrophysics
Optimization of Tessellation-based Statistics: Void Statistics
Yu Liu, Cheng Zhao, Yu Yu et al. (+2 more)
Tessellation methods are extensively employed in the analyses of
cosmic large-scale structure (LSS). However, these techniques are highly sensitive to perturbations in both densities and positions of points, often leading to substantial rearrangements of tessellation configurations. As a result, considerable additional statistical errors are introduced in various tessellation-based statistics, thereby weakening their cosmological constraints. In this work, we identify this issue and propose an efficacious measurement scheme through subsampling and averaging to enhance the stabilities of tessellation-based statistics. As a case study, we apply the new scheme to measure multiple primary void statistics [i.e., void size function (VSF), void two-point correlation function (VTCF), and void power spectrum (VPS)] in two distinct classes of voids, based on Delaunay and Voronoi tessellations, respectively. We notice that the statistical uncertainties in void statistics can be predominantly attributed to tessellation instabilities. Through rigorous testing, we demonstrate that the proposed method can substantially eliminate these scatters to deeply mine the statistical power of void statistics. Specifically, we find that our method can dramatically boost the signal-to-noise ratios (SNRs) of void
Baryon Acoustic Oscillations (BAOs) and significantly improve the constraining power of void statistics on cosmological parameters. These findings showcase enormous application potentials of our new method in maximizing extraction of cosmological information from
galaxy surveys. Importantly, our method is simple yet highly potent with broad applicability, hopefully evolving into a standard framework for measuring tessellation-based statistics in the future.
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All authors Yu Liu, Cheng Zhao, Yu Yu, Zhejie Ding, Jean-Paul Kneib
Mesoscale and Nanoscale Physics
Shu-Hui Zhang, Shu-Qi Liu, Dan-Yang Han et al. (+4 more)
Antiferromagnets (AFMs) are promising for high-density spintronics due to their zero net magnetization, yet conventional AFM spintronics relies on
spin splitting-a requirement that excludes many collinear AFMs with compensated
spin sublattices. Here we exploit the sublattice degree of freedom in a honeycomb AFM with zero
spin splitting. We uncover a coupling between
spin and sublattice: the out-of-plane pseudospin polarization is
spin-dependent, a mechanism we term partial pseudospin-
spin coupling. This allows switching of the pseudospin polarization by reversing the Néel vector. Introducing an
impurity into a specific sublattice induces Friedel oscillations with a sublattice-resolved amplitude ratio dictated solely by the pseudospin polarization, which is directly measurable by
spin-polarized scanning tunneling microscopy. Furthermore, we demonstrate Néel-vector-controlled transmission and a large nonvolatile tunneling magnetoresistance in an all-in-one AFM junction, with pronounced resonant enhancement in gate-tunable two-dimensional devices. Our work establishes a new paradigm-AFM pseudospintronics-that utilizes the sublattice pseudospin in zero-
spin-splitting AFMs, extending spintronics beyond the conventional
spin-splitting paradigm.
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All authors Shu-Hui Zhang, Shu-Qi Liu, Dan-Yang Han, Zhan Kong, Ding-Fu Shao, Wen Yang, Kai Chang
Physics and Society
Perceiving exposure segregation with open urban imagery
Yunke Zhang, Ruolong Ma, Xin Zhang et al. (+4 more)
Socioeconomic exposure segregation – the lack of daily interaction between income groups – erodes social capital and entrenches inequality, yet the specific physical features that drive these behavioral restrictions remain poorly understood. Prior research has quantified where segregation occurs using mobility data, but has not identified how the built environment facilitates or inhibits these interactions. Here we introduce VISAGE, a large multi-modal model-enabled framework that perceives exposure segregation directly from open satellite and street-level imagery across 10,030 communities in 31 U.S. cities. Moving beyond black-box correlations, we operationalize cross-disciplinary sociological theory into an interpretable visual codebook to detect physical regulators of social mixing. We find that the built environment encodes a legible grammar of segregation: "defensible" architectural forms (e.g., fences, gated enclosures) and monofunctional zoning systematically predict higher social isolation, whereas mixed-use infrastructure fosters interaction, explaining substantial variance in mobility-derived segregation patterns (Pearson $r=0.770$). Crucially, we show that inclusionary housing policies manifest in distinct visual signatures associated with higher mixing, suggesting that policy interventions successfully alter the physical landscape to encourage diversity. Our findings offer a scalable pathway to decipher the social production of space, providing a mechanism-based lens to understand how the built environment shapes social behavior.
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All authors Yunke Zhang, Ruolong Ma, Xin Zhang, Yu Shang, Fengli Xu, Tong Xia, Yong Li
Applied Physics
Opportunistic Lower-Terahertz Rainfall Estimation with DSD-Constrained Channel Characterization
Wanzhu Chang, Yuheng Song, Jiabiao Zhao et al. (+8 more)
Rain-induced attenuation and scattering become significant at terahertz (THz) frequencies, and exploiting this rain sensitivity is necessary both to safeguard link reliability and to enable opportunistic environmental sensing without dedicated instrumentation, a capability that remains largely unvalidated on real outdoor channels above 100 GHz. This article investigates opportunistic rainfall estimation using measured lower-terahertz (THz) channels at 140 and 229 GHz. Outdoor measurements over a 41.5-m rain-exposed path are used to characterize rain-induced attenuation and the rainfall dependence of an effective Rician K-factor. Because the path-representative drop-size distribution (DSD) is unavailable, several propagation-model scenarios based on ITU-R P.838-3 and Mie theory with canonical DSDs are employed to quantify model-form sensitivity. These channel characteristics are then used to generate physics-constrained synthetic received-power sequences for training RainFormer, a compact
attention-convolution regression network that combines temporal features with explicit attenuation and fluctuation statistics. Under matched synthetic conditions, RainFormer achieves RMSEs of 0.1782 and 0.2925 mm/h at 140 and 229 GHz, respectively, and outperforms the investigated convolutional and
Transformer baselines in most metric-frequency combinations. Direct application to the independent measured
dataset produces physically consistent rainfall estimates at 140 GHz and demonstrates that received-power fluctuations provide useful information beyond mean attenuation. The results establish a measurement-informed framework for evaluating lower-THz links as opportunistic rainfall sensors while explicitly accounting for propagation-model uncertainty.
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All authors Wanzhu Chang, Yuheng Song, Jiabiao Zhao, Mingxia Zhang, Jie Yang, Kefeng Huang, Kaixin Sun, Hong Liang, Weidong Hu, Fawad Sheikh, Jianjun Ma
Earth and Planetary Astrophysics
The panchromatic JWST dayside spectrum of WASP-121 b reveals a refractory-rich formation
K. Angelique Kahle, Paul Mollière, Laura Kreidberg et al. (+16 more)
One path to understand how
planets form is to link their present-day atmospheric composition to predictions from
planet formation models. For the hottest
planets, the abundances of refractory species can provide a useful formation tracer, complementing the traditionally used C/O and overall
metallicity. Here we investigate the refractory abundance in the atmosphere of the ultra-hot Jupiter WASP-121 b, combining new JWST MIRI/LRS observations with archival NIRSpec/G395H and NIRISS/SOSS data to obtain a panchromatic dayside emission spectrum from 0.6 to 12 $\mu$m. Our
retrieval analysis detects the refractory tracer SiO gas at high confidence, in addition to previously detected volatile species. The atmosphere is enriched in volatile and refractory species, with enhanced refractory-to-volatile ratios of Si/O=$3.54^{+0.86}_{-0.69}$x
stellar and Si/C=$3.05^{+1.12}_{-0.80}$x
stellar, relative to new
stellar abundance constraints from ESPRESSO data. In addition, we confirm the depletion of TiO and the need for an additional source of reflected light opacity with a
geometric albedo of $0.22\pm0.03$. The retrieved dayside temperature profile has a strong inversion layer, with a more complex structure than standard parameterizations can accommodate, and an eclipse map analysis indicates a small eastward hotspot offset of $4.8^{+2.7\circ}_{-2.8}$. Comparing our results with models of
planet formation, we find that the measured enrichment pattern was shaped by
accretion from multiple reservoirs, either through a mixture of solid and gas
accretion interior to the water ice line or through continued solid
accretion during inward migration from farther out in the disk. Finally, we model the
planet's dynamical history and find that it could reach its current high-obliquity orbit as a consequence of a post-formation dynamical event, such as
planet-
planet scattering or von Zeipel-Lidov-Kozai cycles.
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All authors K. Angelique Kahle, Paul Mollière, Laura Kreidberg, Bertram Bitsch, Mara Attia, Silke S. Dainese, Nicholas Storm, Daniel Valentine, Thomas M. Evans-Soma, H.J. Hoeijmakers, Stefan Pelletier, Ludmila Carone, Cyril Gapp, Yoav Rotman, Sophia R. Vaughan, D. A. Christie, Louis-Philippe Coulombe, Christiane Helling, Thomas Henning
Plasma Physics
Plasma Flow Generation and Particle Acceleration from Expanding Magnetic Bubbles
Yang Zhang, Brandon K. Russell, Geoffrey Pomraning et al. (+9 more)
Impulsive
plasma dynamics in the laboratory are often driven by rising electric currents, yet their quantitative
plasma response has not been well established. By means of fully kinetic particle-in-
cell simulations and
laser-driven capacitor-coil experiments, we show that a rising current expels
plasma, forming an expanding
magnetic bubble and accelerating particles. The expansion front velocity scales with the Alfvén speed determined by the
magnetic field at its inner edge and the
plasma density at its outer edge. This mechanism establishes impulsive current drive as a fundamental way that generates
plasma flows and accelerates particles in laboratory
plasmas, with potential relevance to astrophysics.
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All authors Yang Zhang, Brandon K. Russell, Geoffrey Pomraning, Lan Gao, Xiaocan Li, Adam Stainer, William Daughton, Chuanfei Dong, Liang Wang, Peiyun Shi, Kian Orr, Hantao Ji
Quantum Physics
Dynamical Tipping in a Quantum Limit Cycle
Ya-Xin Xiang, Zhengyang Bai and Yu-Qiang Ma
Nonequilibrium systems maintain spatiotemporal order through energy dissipation and
entropy production. Here, we demonstrate this principle by engineering a
quantum limit cycle that emerges from the interplay between a first-order absorbing-state phase transition and feedback mechanism coupling order and control parameters. The
quantum limit cycle manifests dynamical correlations driven by multiplicative
quantum noise and periodic traverses through tipping points, which act as a robust early-warning signal for state transitions. This periodic crossing results in the enhanced dynamical susceptibility and transient rise of long-range correlations near each tipping event and their subsequent disappearance away from it. These critical transitions are accompanied by a sharp increase in the energy dissipation rate, leading to a stepwise accumulation of dynamical
entropy production over time. Our results provide a way for realizing dynamical fluctuations and long-range correlations in strongly interacting driven-dissipative open
quantum systems.
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Computational Physics
False Summit and Silent Drift: A Failure Taxonomy and Efficiency Analysis of LLM-Assisted Multiphysics Simulation in an Open-Source Framework
Chi-Chun Chiang and Shih-Ming He
Multiphysics simulation of
semiconductor processes requires simultaneous command of governing equations, numerical methods, software implementation, and process physics, creating a substantial entry barrier for newcomers. We investigate whether large
language model (LLM) assistance and curated literature guidance can reduce this barrier during the development of a low-pressure chemical vapor deposition (LPCVD) model for
graphene growth using the open-source Multiphysics Object-Oriented Simulation Environment (MOOSE). We compare GPT and Claude across direct prompting, staged development without literature, and staged development with literature guidance. Staged development successfully produced converged simulations but revealed two recurring failure classes. We define a false summit as a simulation that converges and appears physically plausible while implementing incorrect physics, and silent drift as the undetected propagation of unverified assumptions through successive development stages. In our case study, a non-conservative species-transport formulation generated spurious methane depletion that was visually indistinguishable from genuine surface consumption, while an omitted self-limiting surface-reaction term produced physically incorrect growth behavior that the LLM repeatedly rationalized as valid. Literature guidance substantially reduced interaction burden during the most challenging development stage, decreasing
prompt counts by 91% for GPT and 64% for Claude. Based on these observations, we propose an eight-category failure taxonomy, model-specific human oversight strategies, and a stage-gated workflow to improve the detectability of hidden modeling errors. The results demonstrate that LLMs can lower the barrier to multiphysics simulation development, but rigorous physical validation remains essential because apparently reasonable solutions may conceal critical defects
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General Relativity and Quantum Cosmology
Observational Constraints on $f(Q,T)$ Gravity in the Presence of DBI-Essence Scalar Field
Mayur Mune, Praveen Kumar Dhankar, Goutam Manna et al. (+3 more)
We investigate late-time cosmology in extended symmetric teleparallel
gravity coupled to a Dirac-Born-Infeld (DBI) scalar field within $f(Q,T)$
gravity, where $Q$ is the non-metricity scalar and $T$ is the trace of the matter energy-momentum tensor. Working on a spatially flat Friedmann-Lemaître-Robertson-Walker background and treating the
cosmic medium as an effective perfect fluid, we derive the background field equations for $f(Q,T)+\mathrm{DBI}$
gravity and obtain analytic solutions for the linear choice $f(Q,T)=\alpha Q+\beta T$. We then constrain the model parameters with a Markov Chain Monte Carlo analysis using Hubble-rate data, DESI BAO (DR2) measurements, and the Pantheon+SHOES Type~Ia
supernova sample. The joint posteriors (Tables II and III) are broadly consistent with current late-time constraints and allow a direct comparison with $\Lambda$CDM, quantifying the departures driven by the $\beta T$ coupling and the DBI sector. Although the model does not reproduce every observational feature exactly, it provides a statistically viable alternative avenue to the standard paradigm and a useful framework for exploring potential remedies to existing tensions, including the $H_0$ discrepancy, without claiming a definitive resolution.
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All authors Mayur Mune, Praveen Kumar Dhankar, Goutam Manna, Safiqul Islam, Bidisha Samanta, Behnam Pourhassan
General Relativity and Quantum Cosmology
Quantum Memory in Scalar-Induced Gravitational Waves
Waqas Ahmed
Scalar-induced gravitational waves are usually treated as a classical
stochastic background sourced by phase-random
curvature perturbations. We show that this description can miss residual
quantum information. Starting from a decohered two-mode Gaussian scalar state, we derive explicit transfer relations between the scalar anomalous coherence and the covariance
matrix of induced tensor modes. For a localized scalar power spectrum, the ordinary tensor power is sourced by scalar power contractions, whereas the opposite-mode tensor coherence is sourced by scalar anomalous-coherence contractions. This coherence can generate nonzero tensor discord and a connected tensor-power covariance even after scalar
entanglement has vanished. We identify the connected covariance and phase-sensitive strain correlations as probes of
primordial quantum coherence in secondary gravitational-wave backgrounds, and discuss their possible relevance for future space-based interferometers and
pulsar timing arrays.
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High Energy Astrophysical Phenomena
Do Prompt Gamma-ray Burst Fireball Composition Impact on Afterglow Emission? Cases Study for Long GRBs 080916C/090902B and Short GRBs 090510/130603B
Yu Gan, Ren-Jie Xiong, Zi-Qi Wang et al. (+3 more)
Broadband observations with the
Fermi mission reveal that a large fraction of gamma-ray burst (GRB) spectra are dominated by non-thermal emission, while a small fraction are dominated by thermal/quasi-thermal emission, likely indicating the difference in jet composition among GRB. By selecting two typical long GRBs (080916C and 090902B) and two short GRBs (130603B and 090510), we present a comparative analysis to investigate whether the composition of
prompt GRB jets influences the afterglow emission for bursts originating from both massive
star collapse and compact binary mergers. Incorporating emission from both primary and cascade electron populations, we fit the multi-wavelength afterglow lightcurves of these GRBs with the standard forward shock model and analyze the particle acceleration and radiation physics of the jets. Our results show that the afterglow lightcurve
evolution with the characteristic parameters is not related to the composition of the GRB fireball but rather depends on the ambient medium density. The early UV-optical afterglows of the two long GRBs are dominated by synchrotron emission from cascaded $e^{\pm}$ pairs produced via the $\gamma\gamma$ annihilation process, whereas this is not the case for the two short GRBs. These results suggest that the internal energy of the fireball is converted into jet kinetic energy during the
prompt phase, and that the fireball composition leaves no detectable footprint on the afterglow jet. Instead, the density of the ambient medium plays an essential role in shaping the afterglow emission.
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All authors Yu Gan, Ren-Jie Xiong, Zi-Qi Wang, Qi-Yu Yan, Liang-Jun Chen, Xiao-Li Huang
Cosmology and Nongalactic Astrophysics
Dark Energy in the DESI Era: A Brief Review of Evidence, Beyond-$\Lambda$CDM Interpretations, and Tensions
Tian-Nuo Li, Guo-Hong Du, Hao Wang et al. (+3 more)
Recent
baryon acoustic oscillation measurements from DESI provide important new clues for reassessing whether the standard $\Lambda$CDM model offers a sufficient description of the late-time expansion history of the Universe. When combined with
cosmic microwave background and type Ia
supernova data, these measurements show an apparent departure from the $\Lambda$CDM model, commonly described as dynamical dark energy (DDE) with equation of state crossing the phantom divide (i.e., quintom behavior). This review examines the current status of the DESI-motivated indications for DDE and their possible implications for physics beyond $\Lambda$CDM. We discuss how the strength of the preference for DDE depends on the adopted parametrization and
dataset combination, and how residual systematics or internal tensions among
datasets may affect its interpretation. At the background level, several mechanisms beyond $\Lambda$CDM can produce similar expansion histories. We therefore further discuss how the same effective departure from $w=-1$ may arise from physically distinct scenarios, including interacting dark energy, non-minimally coupled
gravity, and non-standard dark matter. Meanwhile, these different new-physics interpretations may have different implications for current cosmological tensions, especially those involving $H_0$, $S_8$, and $\sum m_\nu$. In conclusion, the question posed by DESI is not merely whether dark energy evolves with time, but rather how, within the framework of precision cosmology, to disentangle new physics scenarios from systematic errors.
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All authors Tian-Nuo Li, Guo-Hong Du, Hao Wang, Yun-He Li, Jing-Fei Zhang, Xin Zhang
Optics
Material- and geometry-independent multishell cloaking device
Pattabhiraju C. Mundru, Venkatesh Pappakrishnan and Dentcho A. Genov
In this paper we proposed a multi-shell generic cloaking system. A transparency condition independent of the object's optical and geometrical properties is proposed in the quasi-static regime of operation. The suppression of dipolar scattering is demonstrated in both cylindrically and spherically symmetric systems. A realistic tunable-low loss shell design is proposed based on composite metal-dielectric shell. The effects due to dissipation and dispersion on the overall scattering cross-section are thoroughly evaluated. It is shown that a strong reduction of scattering by a factor of up to 10^3 can be achieved across the entire optical spectrum. Full wave numerical simulations for complex shape particle are performed validating the analytical theory. The proposed design does not require optical magnetism and is generic in the sense that it is independent of the object's material and geometrical properties.
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High Energy Astrophysical Phenomena
A grid of fast-rotating, chemically-homogeneous, supernova and/or long-GRB progenitors
M. Renzo, O. Gottlieb, H. S. Chan et al. (+6 more)
The understanding of the mechanism(s) by which massive
stars collapse and possibly explode is rapidly maturing. Uncertainties in the structure of the
stellar core at the onset of collapse are often dominant in numerical simulations, and a limited number of progenitor grids are available. This is especially true for explosions where rotation and
magnetic fields play a significant or primary role. We present a grid of 113 single-
star models with initial masses $M_{\rm ZAMS}=30-90\,M_{\odot}$ and initial rigid rotation $\omega_{\rm ZAMS}=0.5-0.99\,\omega_{\rm crit}$ computed at $Z=0.001$ with the open-source
stellar evolution code MESA. We adopt a 128-isotope
nuclear reaction network capable of following the weak reactions deleptonizing the core during and after silicon core burning. By construction, these models experience rotationally-induced chemically-homogeneous
evolution, and reach the onset of collapse ($v_{\rm infall}\lesssim -300\,\mathrm{km\ s^{-1}}$) with large and structured amounts of angular momentum, possibly sufficient to form
accretion disks on a proto-compact object. Therefore, these progenitor structures provide a homogeneous set of models with updated input physics and improved algorithmic accuracy to understand
stellar explosions of (some types of) stripped-envelope
supernovae, possibly jetted and/or broad-lined, collapsars or magnetar-powered, and/or long $\gamma$-ray bursts.
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All authors M. Renzo, O. Gottlieb, H. S. Chan, J. A. Goldberg, A. Grichener, K. Sen, N. Shah, E. Farag, Matteo Cantiello
Physics and Society
Ranking football teams via the higher-order decomposition of performance networks
A. Chacoma, J.I. Perotti and O.V. Billoni
We propose a unified methodological framework to quantify team performance in elite football by combining event-level performance metrics, higher-order network representations, and algebraic ranking methods. Using data from the 2017–2018 season of the five major European leagues, we construct metric-specific weighted graphs in which teams are connected through relative performance indicators. These graphs are analyzed via Hodge decomposition, and the gradient component is used to derive metric-based team ratings. The resulting rankings are systematically compared with the true league standings using Pearson and Kendall correlation measures, revealing strong metric- and league-dependent effects. Furthermore, by analyzing the ratio between solenoidal and total flow energies, we show that local cyclic dynamics structurally limit the gradient component's capacity to reconstruct the ranking. This topological inconsistency acts as a structural fingerprint of each league's “competition style” successfully mapping the studied systems into distinct regimes: highly hierarchical structures (England and Italy), tactical parity driven by generalized loops (Germany), and pockets of localized chaos (France and Spain). Lastly, we introduce a composite rating obtained as a parsimonious linear combination of metric-based ratings, optimized separately for each league. This composite approach significantly improves predictive power and allows the relative importance of different performance indicators to be quantified in a league-specific manner. Our results demonstrate how higher-order network methods provide a flexible and interpretable framework to uncover latent performance structures in football, offering a complementary perspective to outcome-based rankings and a general approach applicable to other oppositional sports.
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Quantum Physics
Prethermal cooling with many-body quantum quenches
Jacob F. Steiner, Mohammad Hafezi, Stefan Kehrein et al. (+1 more)
Many-body
quantum quenches are typically associated with heating. In this work, we show that
quantum quenches that perform positive work on the system can still lead to effective cooling of low-energy degrees of freedom if the quench energy is deposited in long-lived high-energy excitations. We discuss this explicitly for a quench of the hopping term t in the strong-coupling (U >> t) fermionic Hubbard model at half filling, where the quench induces a very long-lived non-
equilibrium doublon density. The associated prethermal state persists for a time exponentially large in (U/t)^2. During this time window, we find an effective prethermal temperature that is reduced by the square of the ratio of final to initial hopping amplitude with respect to the initial temperature. This manifests as an effective fluctuation-dissipation relation that holds for doublon-number conserving operators. In a practical implementation the Hubbard system acts as a refrigerant to cool a target system provided the coupling conserves doublon number. Our protocol can be thought of as a
quantum quench many-body generalization of adiabatic demagnetization.
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All authors Jacob F. Steiner, Mohammad Hafezi, Stefan Kehrein, Gil Refael
Soft Condensed Matter
Saturation Coverage in Binary Mixtures of Oriented Regular Polygons via Random Sequential Adsorption
Aref Abbasi Moud
We study saturation in two-dimensional binary mixtures of fixed-orientation regular polygons deposited by random sequential adsorption (RSA). Polygons with (n\in{3,\dots,23}) are considered under an equal-area constraint, isolating shape effects from size effects. Saturated configurations are generated using an adaptive split-voxel RSA
algorithm with exact overlap detection based on the Separating Axis
Theorem, allowing a systematic exploration of all distinct binary shape combinations. Jamming coverage depends strongly on polygon geometry despite identical particle area. Triangle-containing mixtures yield the lowest coverages, whereas axis-aligned squares achieve the maximum observed value, (\phi_sat\approx0.5646). Even-sided polygons consistently outperform neighboring odd-sided polygons, revealing a parity effect associated with centrosymmetry. For odd (n), the pure-species saturation approaches the disk RSA limit (\phi_disk\approx0.547) from below according to (\phi_sat(n)=\phi_disk-c/n^\alpha), with (\alpha\approx2.41\pm0.06), close to the (1/n^2) scaling expected from isoperimetric arguments. Even-sided polygons instead converge from above, indicating a
symmetry-driven packing advantage that disappears only in the circular limit. These trends are explained through the excluded area (E_{AB}=\mathrm{Area}(P_A\oplus(-P_B))), computed analytically via Minkowski sums. Centrosymmetry fixes (E_{AA}=4A_0) for even (n), whereas odd polygons have a larger excluded area that decreases monotonically toward the same limit as (n\to\infty). Saturation coverage is negatively correlated with excluded area, consistent with a mean-field RSA description and directly linking
geometric symmetry to jamming efficiency.
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Solar and Stellar Astrophysics
On the stellar parameter dependence of the combined Fe I and Fe II chromospheric emission-line in the wings of the Ca II K line
Faiber Rosas-Portilla, Luis Zapata, Klaus-Peter Schröder et al. (+3 more)
We present an analysis of the chromospheric emission of Fe I + Fe II in the wing of the Ca II K line of 21 G and K
giant stars.
Stellar parameters and absolute chromospheric fluxes were obtained by comparison with PHOENIX models. The iron-blend emission shows a proportionality with the Ca II K flux for
stars with similar
stellar parameters and also for individual
stars observed at different epochs, confirming that both diagnostics seems to respond to the same underlying chromospheric conditions. We found a dependence of the iron-blend emission on
stellar parameters by fitting a power-law relation. The exponent of the effective temperature statistically matches with that found for Ca II K; which, together with a
metallicity dependence, indicate that the iron-blend may act as an indirect tracer of chromospheric thermal conditions. The chromospheric emission flux ratio (Fe I + Fe II)/Ca II K exhibits a distinct slope change around log g approx. 2.5 dex; which causes the
gravity dependence to be different for
stars with gravities lower and higher than 2.5 dex. This behavior suggests a transition between regimes where the two diagnostics probe similar physical conditions and where they begin to diverge in the sensitivity to the chromospheric extension. We discuss the implications of this behavior for the thermal structure of the lower chromosphere and for the formation heights of both diagnostics.
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All authors Faiber Rosas-Portilla, Luis Zapata, Klaus-Peter Schröder, Sandra González-Enríquez, Dennis Jack, Robert Stencel