Peer Revenue Now accepting positions

Papers

Fresh from arXiv, typeset properly. Highlighted words trade on the market.

Physics

Watch Physics (sign in to use)

Thursday 24 September

High Energy Physics (Phenomenology)

The lepton flavor universality including the $b\rightarrow c l \nu$ process in the $U(1)_X$SSM

This paper calculates the lepton flavor universality including the $b\rightarrow c\ell \nu$ process under the U(1) extension of the minimal supersymmetric standard model ($U(1)_X$SSM), and provides numerical analysis and summary. The numerical results are used to create one-dimensional and multi-dimensional plots to analyze the impacts of various parameters on the ratios $(\frac{R_{J/\psi}}{R^{SM}_{J/\psi}}$, $\frac{R_{{D}_s}}{R^{SM}_{D_s}}, \frac{R_{{D^*}_s}}{R^{SM}_{D^*_s}},\frac{R_{{\Lambda}_c}}{R^{SM}_{\Lambda_c}})$. The results show that several parameters have a certain effect on the ratios. Although it can't match the experimental data very well, with the right combination of parameter values, it can give better numerical results than the Standard Model. This shows that the $U(1)_X$SSM is very helpful for studying $b\rightarrow c\ell \nu$ processes.
Read the full abstract

All authors Meng-Zi Cao, Shu-Min Zhao, Yue-Tong Liu, Shuang Di, Rong-Zhi Sun, Xing-Xing Dong

Optics

Zero-forward Kerker scattering via synthesized complex-frequency excitation

All objects illuminated with light inevitably cast a shadow – a universal phenomenon encapsulated in the fundamental property that all passive systems with plane-wave illumination feature a non-zero forward scattering amplitude. Since Kerker's landmark 1983 paper, considerable effort has been devoted to overcoming this limitation and achieving the elimination of forward scattering – an objective now widely known as the zero-forward Kerker scattering. However, this objective is fundamentally restricted to active systems, requiring either physical gain in materials or virtual gain in the excitation source. Despite advances in active materials science and non-Hermitian photonics, the experimental realization of zero-forward Kerker scattering still remains an open challenge. Here, we show, both theoretically and experimentally, how zero-forward Kerker scattering can be effectively synthesized by a weighted superposition of readily accessible real-frequency responses. Our synthetic recipe builds on creating an artificial pole at a complex frequency that prevails over inherent scattering poles. These findings not only unlock a realistic experimental framework for non-Hermitian light-matter interactions, but also hold technological relevance for non-invasive sensing and imaging.
Read the full abstract

All authors Jianfei Liu{\dag}, Zheng Gong{\dag}, Ao Li, Hongsheng Chen, Stefan Rotter, Xiao Lin

Chemical Physics

Strong-Field-Driven Non-Linear Electron Dynamics in Thiophene Oligomers

The interaction between conjugated molecules and intense electric field pulses drives a plethora of intriguing nonlinear phenomena, including optical limiting. While excited-state absorption was recently identified as the primary mechanism for this effect in thiophene oligomers, open questions remain regarding field-dependent population dynamics under intense laser driving. Using real-time time-dependent density functional theory combined with a determinant-overlap population framework, we track the intensity-dependent nonlinear response of a single thiophene ring (1T) and quaterthiophene (4T) as prototypical members of the oligothiophene family with different length and symmetry. We demonstrate that extended $\pi$-conjugation in 4T lowers nonlinear excitation thresholds by orders of magnitude compared to 1T. State-resolved population dynamics reveal complete ground-state depletion accompanied by sequential excited-state absorption channels under intense driving. High-harmonic generation spectra explicitly reflect molecular symmetry constraints, while energy-resolved occupation densities confirm continuous orbital redistribution across the $\pi^*$-manifold. This work provides dynamic physical insights for engineering organic materials with tailored nonlinear optical properties.
Read the full abstract

Computational Physics

A Physics-Driven Framework for Parametric Periodic-Flow Modeling and Finite-Amplitude Aeroelastic Response Analysis

Periodic unsteady flows are common in forced-motion and fluid-structure interaction problems. Their parametric analysis typically requires repeated high-fidelity simulations, whereas existing reduced-order and surrogate models generally rely on pre-generated flow-field or aerodynamic data. This study proposes a purely physics-driven framework for solving parametric periodic flows and finite-amplitude aeroelastic responses. First, a Periodic Physics-Informed Neural Network (P-PINN) is developed to directly solve periodic flows by imposing temporal periodicity over a single motion cycle, thereby avoiding the need to resolve the long transient evolution preceding the establishment of the periodic state. The flow conditions and motion parameters are further incorporated as network inputs to construct continuous parametric representations of the periodic flow field and aerodynamic forces. On this basis, the parametric aerodynamic model is coupled with the structural dynamic equation through first-order harmonic balance to solve the response amplitude and frequency of a single-degree-of-freedom aeroelastic system. This framework is validated using forced-motion cases of a circular cylinder and an airfoil, demonstrating accurate reproduction of periodic aerodynamic forces, surface load distributions, and instantaneous flow fields under different flow and motion parameters compared with time-marching results. Furthermore, aeroelastic analysis is conducted for an elastically mounted circular cylinder at subcritical Reynolds numbers, and the resulting aeroelastic response agrees well with fully coupled CFD/CSD results. Once trained offline, the parametric model can be repeatedly evaluated for different structural parameter states, enabling the complete aeroelastic response curve to be obtained online within seconds, without repeated long-time fluid-structure interaction time marching.
Read the full abstract

Plasma Physics

Prediction of Re-Ignition Times in Dielectric Barrier Discharges

Discharge ignition events in dielectric barrier discharges (DBDs) self-organise into spatio-temporal patterns with varying degrees of order. The complex dynamics of a DBD and intricate structure of occurring patterns complicate the formulation of predictive, mechanistic descriptions. We present the formulation of a reduced-order model that describes the re-ignition dynamics between consecutive discharges appearing at the same position inside a DBD arrangement. The model is derived from an equivalent electric circuit and validated against fluid-Poisson simulations and experiments performed with a multi-filament arrangement in air-like gas mixtures at atmospheric pressure driven by sinusoidal high-voltage waveforms. The experimental scenarios include a highly ordered regime where discharges ignite at regular time and space intervals generating a pattern stable over several periods, and an unstable regime with discharges appearing at seemingly random positions and times. The model accuracy is assessed in both regimes and it is found that the associated prediction uncertainty provides a quantitative measure of the spatial order of the discharge pattern.
Read the full abstract

All authors Cristian Flores, Hans Höft, Tomáš Hoder, Franz X. Bronold, Klaus-Dieter Weltmann, Markus M. Becker

Atomic Physics

Second-Order Rayleigh-Schrödinger Perturbation Theory for the Grasp

A developed method, based on the stationary second-order Rayleigh-Schrödinger many-body perturbation theory in an irreducible tensorial form, allows us to determine the most important core-valence, core, core-core, and valence-valence correlations for any atom or ion with an arbitrary number of valence and core electrons. This paper presents the Feynman diagrams that describe these correlations. Additionally, it provides the rules for obtaining algebraic expressions in an irreducible tensorial form for any Feynman diagram coming from second-order many-body perturbation theory. Whereas some types of the valence-valence and core-valence correlations are described by the three-particle Feynman diagrams, additional developments to calculate the spin-angular parts of these diagrams have been made to the program library librang of the Grasp2018. As an example of the application of the developed method, the atomic calculations of the energy level structure and transition data for Ar II are presented.
Read the full abstract

Chemical Physics

Full-frequency GW from Cayley-transformed self-energy moments

The dynamical GW self-energy approximation is a key computational tool to provide the fundamental spectrum of electronic systems. We reformulate this approximation, representing the particle and hole parts of the GW self-energy through a highly compact set of Cayley-transformed moment constraints. The Cayley transformation maps real frequencies to the unit circle, keeping the moments bounded as their order increases, ensuring numerical stability and allowing resolution to be focused on an energy range of interest. We calculate these Cayley-transformed moments via an efficient O[N$^4$] scaling contour integration, and from them, construct a Hermitian upfolded Hamiltonian with a linearly scaling dimensionality with system size. A single-shot diagonalization of this effective Hamiltonian gives an explicit full-frequency G0W0 Green's function with manifestly real poles and non-negative spectral weights. This enables quasiparticle energies, satellite features, and their spectral weights to be obtained across the full G0W0 spectrum. Comparisons with exact G0W0 calculations and convergence across the GW100 test set and the larger Chlorophyll A molecule demonstrate substantially faster and more reliable convergence with moment order than an earlier monomial-moment approach. These Cayley moment representations therefore provide a stable, compact, and systematically improvable route to the complete spectral information of zero-temperature GW, without explicit frequency grids, plasmon-pole models and other common approximations, or analytic continuation.
Read the full abstract

Quantum Physics

MagiCFirm: A Runtime for Magic-State Cultivation with Algorithm-Hardware Co-Design

Magic-state cultivation offers a promising alternative for lowering the cost of non-Clifford operations in fault-tolerant quantum computing (FTQC). However, realizing cultivation in practice exposes two challenges: (i) the lack of an open-source classical runtime layer between logical software and physical control, and (ii) the latency constraints on protocol-specific decisions that determine magic-state readiness. To address these challenges, we adopt an algorithm–hardware co-design approach. At the algorithm level, we develop a two-stage early-escape scheme that identifies an informative subset of detectors offline, constructs a compact decoding problem, and performs partial decoding in parallel with complete decoding at runtime, allowing high-confidence attempts to advance before full decoding completes. At the hardware level, we present MagiCFirm, a configurable runtime that combines offline-compiled microprograms with dedicated datapaths for detector construction, event processing, and protocol control, enabling end-to-end execution of magic-state cultivation. Across evaluated configurations, MagiCFirm reduces wall-clock magic-state preparation time by up to 39.3% at matched logical error rate. For a representative magic-state-bound workload, this translates to an estimated 11% reduction in overall application runtime.
Read the full abstract

All authors Jubo Xu, Abbas B. Ziad, Prakash Murali, Hongxiang Fan

Superconductivity

Nodal Orbital-Anti-Phase Superconducting State in Bilayer Nickelates

The recent discovery of high-$T_c$ superconductivity in the bilayer nickelate La$_3$Ni$_2$O$_7$ (La-327) under applied pressure and compressive strain opened a new avenue to elucidate the interplay between multiorbital intralayer and interlayer electronically driven Cooper-pairing in bilayer systems. Depending on the details of the electronic structure in the normal state, the superconducting gap in bilayer nickelates is predicted to have either bonding-antibonding $s_{\pm}$-wave symmetry, driven by dominant interlayer Cooper-pairing, or $d$-wave symmetry with substantial intralayer Cooper-pairing. Despite this general picture, the orbital structure of the superconducting gap in these multiorbital systems has been less explored. Here, we analyze the consequences of an orbital-anti-phase structure of the superconducting gap and discuss its possible experimental signatures. We demonstrate that additional pairs of nodes may appear on the $\alpha$ and/or $\beta$ Fermi surface sheets due to the sign change of the superconducting gap between the involved orbitals. Apart from this additional nodal structure, which is not enforced by the symmetries of the gap function and can be probed in ARPES experiments, the orbital-anti-phase gap modifies the temperature dependence of the superfluid stiffness at low temperatures, providing a concrete experimental prediction to test its realization in bilayer nickelates and related multiorbital systems.
Read the full abstract

All authors Marius Scholten, Steffen Bötzel, Frank Lechermann, Rafael M. Fernandes, Ilya M. Eremin

Mathematical Physics · Cross-listed from math.AP

Lower bounds for heat kernels of elliptic operators with unbounded diffusion, drift, and potential terms

We establish a pointwise lower bound for the heat kernel of the elliptic operator $ \Lambda=(1+|x|^\alpha)\Delta +b|x|^{\alpha-2}x\cdot\nabla-|x|^\beta$, where $d\geq3$, $\alpha>2$, $\beta>\alpha-2$, and $b\in\mathbb R$. For every $\tau>0$, we prove that $$ \begin{aligned} p(t,x,y) &\geq C_\tau e^{\lambda_0t} \left(\frac{1+|y|^\alpha}{1+|x|^\alpha}\right)^{\frac{b}{2\alpha}} \frac{(|x||y|)^{-\frac{d-1}{2}-\frac{\beta-\alpha}{4}}}{1+|y|^\alpha}\\ &\quad\times\exp \left[ -\int_1^{|x|}\sqrt{\frac{s^\beta}{1+s^\alpha}}\,\mathrm ds -\int_1^{|y|}\sqrt{\frac{s^\beta}{1+s^\alpha}}\,\mathrm ds \right] \end{aligned} $$ for all $t\geq\tau$ and $|x|,|y|\geq1$, where $\lambda_0<0$ is the largest eigenvalue of $\Lambda$ and $C_\tau>0$ is independent of $t,x,y$. The proof applies the classical Davies - Simon argument in a weighted symmetric setting.
Read the full abstract

Plasma Physics

The quadratic density response function for non-interacting fermions at arbitrary temperature

We develop and implement the quadratic density response function of non-interacting fermions at arbitrary temperature, frequencies, and wave vectors. Starting from a Green's function formulation, we derive the quadratic response and demonstrate its equivalence to the result obtained from the Wigner equation. We further derive the classical limit through a perturbative expansion of the Vlasov equation and demonstrate that the quantum and classical formulations agree in the high-temperature limit. We analyse the limiting behaviour with respect to wavenumber and derive the zeroth harmonic response. Two independent implementations are provided and extensively benchmarked against density-functional theory, canonical path integral Monte Carlo (PIMC), and grand canonical PIMC simulations. As the density response of the interacting electron gas is commonly modelled through the ideal response functions and approximate models for the local field correction, the presented formulation will also allow for more complete explorations of interacting systems. Especially, our efficient implementation, which evaluates the ideal static and dynamic quadratic response functions in less than 0.5 ms on a 1.3 GHz processor, will enable evaluation of quadratic corrections to integrated quantities such as interaction potentials and stopping powers in warm dense matter.
Read the full abstract

All authors Pontus Svensson, Jan Vorberger, Zhandos A. Moldabekov, Panagiotis Tolias, Paul Hamann, Xuecheng Shao, Cheng Ma, Tobias Dornheim

Materials Science

Rational Design of Low-Dimensional Hybrid Organic/Inorganic Interfaces for Enhanced Second-Harmonic Generation

Hybrid interfaces formed by push-pull organic molecules physisorbed on two-dimensional (2D) semiconductors provide a structurally tunable platform for engineering second-harmonic generation (SHG). However, predicting and optimizing their macroscopic response remains a formidable challenge due to the phase-sensitive interference between the nonlinear responses of the adlayer and substrate. Here, we develop a physics-informed computational screening framework that decomposes the effective second-order susceptibility into its constituent substrate, molecular, and electric-field-induced SHG channels. Validated by fully atomistic first-principles calculations across representative interface structures, this model maps the complete orientation-resolved tensor landscape of chemically modulated carbon-conjugated polar molecules on 2D substrates with distinct symmetry. Crucially, our findings dismantle the conventional reliance on static polar descriptors, demonstrating that the ground-state permanent dipole magnitude is a fundamentally unreliable proxy for macroscopic nonlinear response. Instead, we show that the ultimate criterion for SHG maximization is encoded in the phase-resolved projection of the full anisotropic molecular hyperpolarizability tensor. On non-centrosymmetric substrates, the coherent interference between the physisorbed adlayer and the underlying 2D matrix induces a characteristic Fano-like asymmetry and ranking reversals that are entirely absent on centrosymmetric platforms. By establishing that functionalization topology, dynamic spatial orientation, and substrate point-group symmetry constitute a single, non-separable parameter space, this work provides a systematic blueprint for the rational assembly, predictive discovery, and non-invasive characterization of next-generation low-dimensional hybrid materials for nonlinear optoelectronics.
Read the full abstract

Optics

Observation of symmetry breaking in time-varying scattering systems

From the Higgs mechanism to magnetic ordering, spontaneous symmetry breaking organizes physics across scales. Whether an analogous transition governs waves scattered by periodically driven structures has remained an open experimental challenge. Here we demonstrate a universal symmetry-breaking transition in a periodically driven finite scattering system. By measuring the multispectral Floquet scattering matrix of a strongly modulated microwave resonator, we observe a transition from an unbroken symmetry regime with scattering eigenvalues of equal modulus to a broken symmetry regime where their moduli split apart, through an exceptional point. At parametric resonance, this transition culminates in coherent perfect absorption, where a tailored multispectral input state is completely absorbed without outgoing radiation, the singular limit of the underlying transition. Because it arises from the general algebraic structure of the Floquet scattering matrix rather than from implementation-specific details, this transition should occur broadly in such systems. Unlike instability phenomena in bulk driven media, it emerges in the eigenstructure of a finite scattering operator that couples waves across multiple frequency channels. Our results establish Floquet scattering as an experimentally accessible platform for the observation of symmetry breaking and for dynamic wave control in driven photonic systems.
Read the full abstract

All authors Miguel Verde, David Globosits, Thomas F. Allard, Calvin M. Hooper, Simon A. R. Horsley, Stefan Rotter, Paloma A. Huidobro, Ian R. Hooper

Quantum Physics

Quantum Uncertainty and Particle Trajectories: From Heisenberg and Schrödinger to Constructive Dynamical Models

Quantum uncertainty emerged from two strikingly different routes to quantum mechanics. Heisenberg's matrix mechanics replaced the classical description of atomic orbits by relations among observable transition quantities and led, in 1927, to the uncertainty relation and its influential measurement-based interpretation. Schrödinger's wave mechanics grew instead from the Bose–Einstein and de Broglie developments and restored a continuous space-time description through matter waves. The two formalisms were soon shown to be closely related, but neither historical route by itself settles the ontological question of whether particles may possess underlying trajectories. After reviewing these developments, including Einstein's criticism of a simple observability doctrine and Mott's wave-mechanical account of straight cloud-chamber tracks, we distinguish precise quantum uncertainty relations from the stronger claim that quantum mechanics excludes definite microscopic histories. We then compare Feynman paths, Bohmian trajectories, Nelson's stochastic mechanics, and finite-speed persistent Goldstein–Kac dynamics. The Kac process has continuous, piecewise differentiable finite-speed paths; its diffusion limit approaches Wiener kinematics, while analytic continuation of its two-sector dynamics is related to Dirac evolution. These examples show that quantum uncertainty relations constrain observable statistics without, by themselves, uniquely determining an underlying path geometry.
Read the full abstract

Instrumentation and Methods for Astrophysics

GIMLI: a toolkit connecting linear and non-linear magnetohydrodynamic regimes

In this work, we present the General Interface for MPI-AMRVAC / Legolas Interconnection (or GIMLI, for short) as a toolkit for in-depth (magneto)hydrodynamic studies combining linear and non-linear methods. Acting as a bridge between the linear (M)HD spectroscopy code Legolas and the non-linear simulation code MPI-AMRVAC, GIMLI facilitates the initialization of non-linear MPI-AMRVAC simulations with linear solutions. We showcase this functionality on both Cartesian and cylindrical setups, covering representative plasma physical and astrophysical scenarios: Parker unstable magnetized atmospheres, interchange modes in a straight tokamak setup, resistive Harris sheet evolutions and thermally modified discrete Alfvén waves in coronal loops. We offer suggestions on how to combine linear and non-linear methods, and demonstrate how to leverage GIMLI in the process.
Read the full abstract

Superconductivity

Superconducting spin valve as a sensitive probe of spin-orbit coupling anisotropy

Spin-orbit coupling (SOC) plays a central role in modern condensed matter physics and is crucial for the development of spin-based devices and quantum technologies. In particular, the interplay between Rashba SOC (R-SOC), arising from structural inversion asymmetry, and Dresselhaus SOC (D-SOC), due to bulk inversion asymmetry, significantly influences spin coherence and manipulation in two-dimensional and topological systems. Disentangling these SOC components is essential for spintronics, superconducting spintronics, or topological superconductivity. In this study, we experimentally investigate in-plane low-bias conductance anisotropy in epitaxial Fe/MgO/V/MgO/Fe/Co junctions under varying temperature and magnetic field conditions. By applying a theoretical model that accounts for distinct R-SOC and D-SOC contributions, we interpret the observed anisotropy as a reliable method to disentangle these effects. Comparison between experiment and theory reveals a 5 % contribution of D-SOC to total SOC, attributed to periodic interfacial lattice mismatch defects confirmed by high-resolution scanning transmission electron microscopy (STEM). Our findings offer a practical approach to isolate interfacial SOC components in superconducting spintronic systems with implications for engineering in spintronic and quantum devices, and provide further evidence of superconducting spin-triplet pairing in Fe/MgO/V-based superconductor/ferromagnet heterostructures.
Read the full abstract

All authors Pablo Tuero, Andreas Costa, Maria Varela, Yuan Lu, Jaroslav Fabian, Farkhad G. Aliev

General Relativity and Quantum Cosmology

Asymptotic expansion of cavity Quasi-Normal Modes in Schwarzschild de-Sitter black hole

We study large-overtone quasi-normal modes of a massive scalar field in a four-dimensional Schwarzschild de-Sitter black hole in the presence of a wall placed at the static sphere. Dirichlet boundary condition is imposed at the wall. At leading order the quasi-normal modes with large overtones scale as $n$ for $n\gg 1$ and are inversely proportional to the bouncing time. We analyze correction terms up to $n^{-1}$ order in the asymptotic expansion.
Read the full abstract

Strongly Correlated Electrons

Mixed-Valent Magnetism in CeFe$_2$ from Multi-Impurity DFT+DMFT

The microscopic origin of magnetism in CeFe$_2$ has remained unresolved for almost forty years, where polarized-neutron diffraction and x-ray magnetic circular dichroism infer markedly different Ce $4f$ spin and orbital moments, that also are in disagreement with theory. We show here that within a relativistic multi-impurity DFT+DMFT framework, where the Fe $3d$ states are treated by spin-polarized T-matrix fluctuation exchange and Ce $4f$ orbitals by a bath-coupled configuration-interaction solver, this long standing problem is resolved. This level of theory is exclusive in reproducing magnetic moments (spin and orbital) for both the Ce and Fe atoms, yielding a total moment in agreement with the measured saturation moment. The theory put forth here is much closer to the atom specific moments reported from XMCD, compared to values from polarized-neutron diffraction. The occupation $\langle n_f\rangle=0.85$ and charge variance $\delta n_f^2=0.27$ establish substantial valence fluctuations, while the spectral function simultaneously recovers significant weight at the Fermi level together with separate incoherent structures. These results identify bath-mediated polarization and configuration mixing as the essential ingredients governing the electronic structure and magnetism of CeFe$_2$.
Read the full abstract

Nuclear Theory

Measuring short-range correlations using relativistic heavy-ion collisions

We propose a novel method to measure the strength and isospin dependence of short-range correlations (SRCs) in nuclei with their collisions at relativistic energies. Since nucleons in the high-momentum tail (HMT) induced by SRCs have large transverse velocities, we find that measuring the yield ratio of free spectator neutrons at large to small transverse distances detected by Zero-Degree Calorimeter (ZDC) array may probe the fraction of nucleons in the HMT. In addition, measuring the yield ratio of ZDC neutrons in central $^{96}$Zr+$^{96}$Zr to $^{96}$Ru+$^{96}$Ru collisions at large transverse distances may probe the isospin dependence of the HMT and SRCs. Compared to traditional scattering experiments, our study illustrates that relativistic heavy-ion collisions may serve as an alternative way of measuring SRCs in colliding nuclei with less final-state interactions.
Read the full abstract

Classical Physics

3D modelling of strain concentration due to PCI within the fuel code ALCYONE

In this paper, the 3D scheme of the fuel code ALCYONE is applied to a database consisting of more than 50 base irradiations and ramp tests performed on rods with UO 2 , MOX or Cr-doped UO 2 fuels and Zy4 or M5__ cladding tubes with burn-ups up to 70 GWd/tU. The ability of the 3D scheme to predict the behaviour of a single fuel pellet -cladding element situated at the maximum Linear Heat Rate (LHR) during ramp testing is demonstrated by comparing the following experimental and calculated data: residual clad diameter after base irradiation and ramp test, height of inter-pellet and mid-pellet ridges after base irradiation and ramp test, dish filling after ramp test. In the second part of the paper, 3D simulations that catch the stress -strain localization at the triple point are presented. It is shown that the stress-strain concentration occurs only at the end of the power transient and is quickly relaxed by pellet and clad creep.
Read the full abstract

All authors J. Sercombe, Jérôme Julien, Frederic Michel, Bruno Michel, Éric Fédérici

Chaotic Dynamics

Attractors and basins generated by repeated sums of prime factors of natural numbers

Integer maps are discrete dynamical systems defined on the natural numbers. In this paper, we investigate the dynamics of the shifted Alladi-Erd{\H o}s map, a one-parameter family of integer maps in which each composite number is mapped to the sum of its prime factors, while each prime is mapped to $n+A$, where $A \in \mathbb{N}$ is a fixed shift parameter. By systematically exploring the parameter space for $2 \leq A \leq 10^5$, we uncover a rich bifurcation structure characterized by the emergence, disappearance, and reorganization of attractor cycles as the shift parameter varies. We find that although several attractors may coexist for a given value of $A$, for most values of $A$, almost all natural numbers belong to the basins of only two dominant attractors. Using elementary number theoretic arguments, we explain the observed bifurcation diagram. We further characterize the attractor cycles and quantify the distribution of their basin sizes across the parameter space. Our results reveal an unexpectedly rich landscape of arithmetic dynamics arising from a remarkably simple integer map. %and provide a systematic characterization of how attractors and their basins evolve as shift parameter is varied.
Read the full abstract

Pattern Formation and Solitons

Adiabatic Theory Data on Strongly Chirped Dissipative Solitons of the Cubic-Quintic Nonlinear Ginzburg-Landau Equation

This data article provides the datasets, symbolic derivations, and scripts used to reproduce master diagrams, stationary-phase spectra, windowed first-order coherence functions, and quantum-noise stability maps for strongly chirped dissipative solitons of the cubic-quintic complex Ginzburg-Landau equation in normal and anomalous group-delay dispersion regimes. The repository includes node-regularized normal-dispersion spectra and energies; small-parameter expansions of the branch roots; cavity-map gain-loss update relations; Airy uniformization at the normal-dispersion spectral edge; anomalous-dispersion spectra and coherence calculations; and processed tables for plotting and stability analysis. OriginLab projects are accompanied by open-format .csv/.txt numerical tables to support reuse without proprietary plotting software. Data and code repository: https://doi.org/10.5281/zenodo.22690899.
Read the full abstract

All authors V. L. Kalashnikov, E. Sorokin, A. Rudenkov, I. T. Sorokina

Mesoscale and Nanoscale Physics

Valley Berry curvature dipole induced nonlinear valley Hall effect

Valley Hall effect is a signature effect in the field of valleytronics, and recent studies have pushed this effect into the nonlinear regime. Here, we reveal a previously unexplored type of nonlinear valley Hall effect which arises from a valley Berry curvature dipole (vBCD) mechanism. We show this nonlinear valley Hall effect is forbidden for conventional time-reversal-connected valleys, but is supported in the class of valleytronic systems featuring time-reversal-invariant valleys. The candidate layer groups and detailed symmetry constraints on vBCD are obtained. It shows the nonlinear valley Hall response, as well as the nonlinear charge Hall response, can be well controlled by tuning the driving field direction. We demonstrate our proposal in an effective model study and in a concrete material example, strained Nb$_{3}$SBr$_{7}$, by first-principles calculations. The nonlocal transport signature of this vBCD induced nonlinear valley Hall effect is also discussed.
Read the full abstract

All authors Lulu Xiong, Xue-Jin Zhang, Zeying Zhang, Yinning Zhou, Jin Cao, Cong Xiao, Shengyuan A. Yang

Optics · Cross-listed from eess.IV

A Unified Frequency-Domain Model for Cascaded Filter-Interpolation Modulation in Tomographic Reconstruction

The fidelity of image reconstruction from projections in linear inverse problems, such as tomography, is critically dependent on the synergistic interaction between frequency-domain filtering and spatial-domain interpolation. However, a physical model that can quantitatively describe how these two components cascade interact in the frequency domain and ultimately determine image quality is still lacking to this day. Here, we introduce a unified frequency-domain model that conceptualizes the combined effect of filtering and interpolation in the filtered backprojection (FBP) algorithm as a cascaded modulation process. This model demonstrates that the effective reconstruction spectrum is determined by the original projection data being sequentially modulated by the frequency responses of the filter and the interpolation kernel. Comprehensive numerical simulations and synchrotron radiation CT experiments validate the model, confirming its power to explain the performance hierarchy of classical filter-interpolation pairs under both ideal and noisy conditions. The model successfully predicts key performance characteristics, including spatial resolution and structural fidelity, thereby elucidating the physical principles behind the efficacy of specific combinations. This work establishes a generalizable theoretical foundation for analyzing cascaded systems in linear inverse problems, moving the practice of algorithm selection in computational imaging from empiricism to a principled, physics-based paradigm.
Read the full abstract

All authors Detian Li, Yang Zou, Penghao Geng, Shengkun Yao

Statistical Mechanics

Eigenoperator Entanglement Statistics in Local Lindbladians

Random matrix spectral statistics are widely used to diagnose quantum chaos in open systems, but whether chaotic eigenvalue correlations are accompanied by Haar-typical eigenoperators remains unclear. We study the operator-entanglement statistics of Liouvillian eigenoperators with near-maximal entanglement, analogous to states near the middle of the spectrum in Hamiltonian systems. Using the Kullback-Leibler divergence, we show that Haar-random statistics accurately describe both the Ginibre and class-AI$^\dagger$ Gaussian ensembles. For purely dissipative random Lindbladians, we find that locality of the jump operators drastically alters the eigenoperator-entanglement statistics. Nonlocal Lindbladians remain relatively close to Haar-random behavior, whereas local Lindbladians deviate increasingly from random-matrix statistics with system size. Moreover, unlike in Hamiltonian systems, the most highly entangled eigenoperators of local Lindbladians do not generally lie in the region of largest density of states, owing to the clustered structure of the complex eigenspectrum. We introduce an iterative $\sigma$-clipping scheme to extract the high-entanglement distribution without preselecting a spectral window, and find that it is Gaussian for nonlocal Lindbladians but log-normal for local ones. Remarkably, the same log-normal distribution, with no additional fitting, also describes dissipative mixed-field Ising chains belonging to distinct non-Hermitian symmetry classes. Our results therefore point to a universal eigenoperator-entanglement distribution for local Lindbladians that is not captured by generic non-Hermitian random-matrix ensembles.
Read the full abstract

Astrophysics of Galaxies

A Census of Stellar-mass Black Holes in the Milky Way with POPKIN. I. Isolated Black Holes

Gravitational-wave observations have revealed hundreds of stellar-mass black holes, yet only about two dozen are known in the Milky Way, almost all in binaries. We present POPKIN, a Python framework that couples single- and binary-star evolution with Galactic orbital dynamics to trace black-hole progenitors from the zero-age main sequence to the present-day isolated black-hole (IBH) population. Across ten models varying the supernova (SN) prescription, mass-transfer efficiency, and common-envelope ejection efficiency, the total IBH abundance is controlled primarily by the SN prescription. Our fiducial model, with a recently proposed metallicity- and stripping-history-dependent SN prescription, predicts $\sim4\times10^7$ IBHs in the Galaxy, including $\sim8\times10^4$ within $1\,\rm{kpc}$ of the Sun; alternative SN prescriptions predict $\sim(1-2)\times10^8$ IBHs. The fiducial model yields a bimodal mass distribution, peaking near $9\,M_{\odot}$ and $20\,M_{\odot}$, with a deficit at $13-17\,M_{\odot}$. This distinguishes it from alternative prescriptions, some of which populate the $2-5\,M_{\odot}$ mass-gap region. Non-kicked IBHs follow nearly circular orbits near the Galactic plane, with typical peculiar velocities of $20-30\,\rm{km\,s^{-1}}$, whereas kicked systems undergo stronger radial migration and span a broader velocity range. We estimate $\sim5\times10^3$ accreting IBHs with $F_{\rm X}>10^{-14}\,\rm{erg\,s^{-1}\,cm^{-2}}$, nearly all non-kicked; this estimate is sensitive to the adopted radiative-efficiency and hot-flow treatments. For a Roman-like bulge survey, our fiducial model predicts $\sim360$ intrinsic IBH microlensing events over five years in a $1.70\,\rm{deg^2}$ effective area, before survey-selection effects. We propose that long-timescale microlensing events from IBHs can strongly constrain the SN physics governing stellar-mass black hole formation.
Read the full abstract

All authors Jian-Guo He, Yong Shao, Yu-Dong Nie, Gui-Yu Wang, Xiao-Tian Xu, Chen Wang, Xiao-Jie Xu, Xiang-Dong Li

Quantum Physics

Representation-Dependent Recoverability in Quantum Compilation

Fault-tolerant compilation can disperse high-level structure: schedules split an accumulated phase across rounds, gate synthesis replaces an angle by a Clifford+$T$ word, and randomized compiling spreads rotations over sign-randomized fragments. They preserve the computation but change how cheaply a downstream compiler can recover the aggregate phase data. We formalize this representation-dependent recoverability by charging two channels: output committed before the suffix arrives, and a serialized restart state crossing the cut. For an $r$-round accumulation of a commuting layer with $m$ generators at accuracy $\epsilon$ ($K_\epsilon=\Theta(1/\epsilon)$), any $p$-pass compiler correct on every valid stream with failure probability at most $\delta$ obeys $\overline{A}_p+(2p-1)S\geq(1-\delta)m\log_2 K_\epsilon-h_2(\delta)$, where $\overline{A}_p$ is committed output and $S$ is the crossing-state cap. The bound covers compile-time randomized compiling; a memory-capped block compiler attains it within a constant factor, and direct semantic aggregation reaches compact output with logarithmic state. The two channels are not always interchangeable. A compiler whose committed prefix is executed at the cut pays a toll the state channel never pays: the entropy $\log_2\binom{m}{k}$ of the mask naming which $k$ coordinates it commits early. Compilers that defer or buffer pay none of it. We prove both directions and, with instrumented compilers under a preregistered protocol, measure a per-generator toll matching $\log_2\binom{m}{k}/k$ that vanishes for a public mask and a buffered control. Under a disclosed fixed-total-error Clifford+$T$ and surface-code model, a materialize-first pipeline costs orders of magnitude more logical $T$ states and spacetime volume than a semantic-first one. Phase semantics should therefore be preserved until aggregation whenever the interface permits.
Read the full abstract

High Energy Physics (Phenomenology)

Topological Axi-Higgs Dynamics in Anomalous $U(1)$ Portals

We develop an effective axi-Higgs model with one Standard Model Higgs doublet, one charged hidden Higgs and an anomalous Abelian vector portal. Extending previous Higgs–Stueckelberg constructions, we derive the Stueckelberg kinetic term by decoupling a heavy scalar radial mode and identify the gauge-invariant physical pseudoscalar from the mixing of the surviving scalar phases. A single instanton-motivated periodic interaction determines the axi-Higgs mass, its couplings to the hidden radial excitation and the sine-Gordon kink in the fixed-radial-field limit. We construct the anomaly-canceling gauge completion, using an Abelian A–B example to introduce the mechanism before its non-Abelian hidden-sector realization. We examine the relation between the periodic potential, the hidden gauge dynamics and the theta-vacuum energy, identifying the invariant angle through the anomalous Yukawa phase rotation. The vector portal gives a coherent elastic nuclear-scattering cross section and permits additional axi-Higgs emission, whose diagrams and kinematic threshold we determine. Numerical examples illustrate the mass and interaction scales, and we investigate conditional thermal relic abundances and their cosmological implications.
Read the full abstract

Cosmology and Nongalactic Astrophysics

Testing cosmic acceleration from thermogravity without vacuum energy

We present a first background-level observational test of a thermogravity theory in which the Einstein equations are clipped to a trace-free version, the cosmological constant $\Lambda$ does not gravitate, and controlled violations of energy conservation obstruct the usual reinstatement of $\Lambda$ as an integration constant. We therefore set $\Lambda=0$ and ask whether late-time acceleration can instead be generated solely by energy non-conservation, with no extra background parameter relative to flat $\Lambda\mathrm{CDM}$. We contrast a minimal universal implementation with a model in which only CDM partakes in non-conservation. The universal model is strongly disfavored when combining Supernovae and BAO distances, with the inclusion of DESI BAO worsening the fit by $\Delta\chi^2\simeq 51$ relative to $\Lambda\mathrm{CDM}$, because matter creation ties the intermediate-redshift normalization of $H(z)$ too rigidly to the present acceleration. This conclusion, however, should be interpreted with caution, since universal non-conservation would modify the observational dictionary itself. By contrast, restricting non-conservation to CDM leaves baryonic and photon observables unaffected at the background level and therefore allows a self-contained analysis. The resulting $\xi\mathrm{CDM}$ model, which can be thought of as a one parameter extension of $\Lambda\mathrm{CDM}$, provides an improved fit relative to $\Lambda\mathrm{CDM}$ for the background dataset combinations considered, with improvements reaching $\Delta\chi^2=-4.85$ and a maximum Bayesian preference of $\ln\mathcal{B}=2.77$. However, when the BAO ruler is calibrated using BBN or CMB information, the reduced effective early-time CDM density increases the sound horizon and drives $H_0$ towards lower values, thereby increasing rather than alleviating the tension with the distance-ladder calibration.
Read the full abstract

All authors Dong Ha Lee, João Magueijo, Carsten van de Bruck, Eleonora Di Valentino

Fluid Dynamics

Effect of fuel stratification length scale on thermodiffusively unstable lean hydrogen flames

Lean premixed hydrogen flames are highly susceptible to thermodiffusive instabilities, which generate complex cellular structures and enhance propagation speed. In practical combustors, incomplete premixing introduces spatial variations in local equivalence ratio upstream of the flame. This work investigates how the length scale of inlet fuel stratification affects the structure and propagation of lean laminar hydrogen flames using direct numerical simulations with detailed chemistry and transport. Controlled sinusoidal perturbations of fuel mass fraction are imposed at moderate amplitude, leading to local equivalence-ratio variations of $\phi \simeq 0.45-0.55$ in the flame region. Seven stratification wavelengths, from $\lambda = 15.4\delta_f$ to $133.3\delta_f$, are examined at constant density-weighted global equivalence ratio. Additional unity-Lewis-number simulations separate geometrical effects from differential transport. The results reveal a strongly scale-dependent response. In unity-Lewis-number flames, stratification organises the front at the imposed wavelength and monotonically increases flame surface area and propagation speed with wavelength. With differential diffusion, large wavelengths ($\lambda \gtrsim 40\delta_f$) produce a similar large-scale organisation, with rich channels forming forward bulges and lean channels recessed cusps, while thermodiffusive cells remain superimposed. This increases flame surface area and global propagation speed. At smaller wavelengths ($\lambda \lesssim 29\delta_f$), composition gradients interfere with intrinsic thermodiffusive cellular dynamics, reducing flame surface area and propagation speed relative to the perfectly premixed reference. These findings identify stratification length scale as a key parameter controlling the interaction between moderate mixture inhomogeneity and thermodiffusive instability in lean hydrogen flames.
Read the full abstract

All authors Filippo Fruzza, Sofiane Al Kassar, Rachele Lamioni, Chiara Galletti, Antonio Attili