Tootfinder

Stability of lattice Boltzmann schemes for initial boundary value problems in raw formulation
Thomas Bellotti (EM2C)
https://arxiv.org/abs/2507.13108 https…

Stability of lattice Boltzmann schemes for initial boundary value problems in raw formulation
We study the stability of one-dimensional linear scalar lattice Boltzmann schemes for hyperbolic equations with respect to boundary data. Our approach is based on the original raw algorithm on several unknowns, thereby avoiding the need for a transformation into an equivalent scalar formulation-a challenging process in presence of boundaries. To address different behaviors exhibited by the numerical scheme, we introduce appropriate notions of strong stability. They account for the potential abs…

Well-posedness of the Boltzmann and Landau Equations in Critical Spaces
Ke Chen, Quoc-Hung Nguyen, Tong Yang
https://arxiv.org/abs/2509.14845 https://arxiv…

Well-posedness of the Boltzmann and Landau Equations in Critical Spaces
This paper investigates the well-posedness of the inhomogeneous Boltzmann and Landau equations in critical function spaces, a fundamental open problem in kinetic theory. We develop a new analytical framework to establish local well-posedness near a global Maxwellian for both equations, under the assumption that the initial perturbation is small in a critical norm. A major contribution lies in the introduction of a novel anisotropic norm adapted to the intrinsic scaling invariance of the equatio…

A collisional model of odd fluids: from Boltzmann equation to chiral hydrodynamics
Ege Eren, Michel Fruchart, Vincenzo Vitelli
https://arxiv.org/abs/2508.12944 https://

A collisional model of odd fluids: from Boltzmann equation to chiral hydrodynamics
When the time-reversal and parity symmetries in a fluid are broken, transverse transport coefficients can arise in response to perturbations, an example being odd viscosity. We refer to these systems as odd fluids. While much progress has been made in the continuum theory of odd-viscous fluids, and non-collisional models for odd viscous fluids have been proposed, a classical microscopic description in which the transverse responses originate from collisions is lacking. In this paper, we show th…

Surrogate Quantum Circuit Design for the Lattice Boltzmann Collision Operator
Monica L\u{a}c\u{a}tu\c{s}, Matthias M\"oller
https://arxiv.org/abs/2507.12256

Surrogate Quantum Circuit Design for the Lattice Boltzmann Collision Operator
Direct numerical simulation of turbulent flows at high Reynolds numbers remains a major challenge for traditional computational fluid dynamics (CFD) tools running on classical computer hardware. This has motivated growing interest in quantum algorithms for CFD to enable flow simulations on quantum computers. The reason being that these computers are expected to deliver potential speed-ups for certain problems. One promising quantum CFD approach is a fully quantum implementation of the lattice B…

Global stability of the inhomogeneous sheared Boltzmann equation in torus
Renjun Duan, Shuangqian Liu, Shunlin Shen
https://arxiv.org/abs/2509.13921 https://

Global stability of the inhomogeneous sheared Boltzmann equation in torus
Homo-energetic solutions to the spatially homogeneous Boltzmann equation have been extensively studied, but their global stability in the inhomogeneous setting remains challenging due to unbounded energy growth under self-similar scaling and the intricate interplay between spatial dependence and nonlinear collision dynamics. In this paper, we introduce an approach for periodic spatial domains to construct global-in-time inhomogeneous solutions in a non-conservative perturbation framework, chara…

Simulation of heavy quarkonium equilibration in the quark-gluon plasma
Shouxing Zhao, Min He
https://arxiv.org/abs/2508.11897 https://arxiv.org/pdf/2508.11…

Simulation of heavy quarkonium equilibration in the quark-gluon plasma
We simulate the heavy quarkonium equilibration through transport in a static and homogeneous quark-gluon plasma (QGP) box within the semi-classical Boltzmann approach incorporating both the leading-order and next-to-leading-order dissociation and regeneration reactions. The scattering amplitudes involved are taken from perturbative computations based on effective color-electric dipole coupling of the heavy quarkonium with thermal gluons. By coupling the Langevin simulation of single heavy quark…

Breaking the Strings: the signatures of Cosmic String Loop Fragmentation
Pierre Auclair
https://arxiv.org/abs/2508.11596 https://arxiv.org/pdf/2508.11596…

Breaking the Strings: the signatures of Cosmic String Loop Fragmentation
We study the impact of fragmentation on the cosmic string loop number density, using an approach inspired by the three-scale model and a Boltzmann equation. We build a new formulation designed to be more amenable to numerical resolution and present two complementary numerical methods to obtain the full loop distribution including the effect of fragmentation and gravitational radiation. We show that fragmentation generically predicts a decay of the loop number density on large scales and a devia…

Computational uncertainties in lattice thermal conductivity prediction of crystalline solids
Yagyank Srivastava, Amey G. Gokhale, Ankit Jain
https://arxiv.org/abs/2509.14702 htt…

Computational uncertainties in lattice thermal conductivity prediction of crystalline solids
We report computational uncertainties in Boltzmann Transport Equation (BTE)-based lattice thermal conductivity prediction of 50 diverse semiconductors from the use of different BTE solvers (ShengBTE, Phono3Py, and in-house code) and interatomic forces. The interatomic forces are obtained either using the density functional theory (DFT) as implemented in packages Quantum Espresso and VASP employing commonly used exchange correlation functionals (PBE, LDA, PBEsol, and rSCAN) or using the pre-trai…

Non-Perturbative Solutions to the Vlasov-Boltzmann Equation for Weakly Ionized Plasmas
Joel Saucedo, Uday Lamba, Hasitha Mahabaduge
https://arxiv.org/abs/2507.10565

Non-Perturbative Solutions to the Vlasov-Boltzmann Equation for Weakly Ionized Plasmas
The electron energy distribution function (EEDF) in low-temperature plasmas exhibits features not fully captured by classical collisional models, particularly across the transition from kinetic to hydrodynamic regimes. This work attributes these phenomena to a dynamically broken scale invariance within the Vlasov-Boltzmann equation. By applying renormalization group (RG) techniques directly to the kinetic operator, we derive non-perturbative EEDF solutions valid across a range of collisionality…

Electrohydrodynamics of a pair of leaky dielectric droplets on the solid substrate: A lattice Boltzmann study
Jiang Peng, Xi Liu, Zhenhua Chai, Changsheng Huang, Xiufang Chen
https://arxiv.org/abs/2508.10037

Electrohydrodynamics of a pair of leaky dielectric droplets on the solid substrate: A lattice Boltzmann study
In this work, the electrohydrodynamics of a pair of leaky dielectric droplets on a solid substrate is investigated by the phase-field-based lattice Boltzmann method. Different from a pair of suspended droplets that may coalesce or separate, two leaky dielectric droplets on the substrate exhibit more complex modes due to the effects of wettability and electric force. The results show that when a horizontal electric field is applied, five different modes with electrostatic attractive force are ob…

Disentangling Boltzmann brains, the time-asymmetry of memory, the H theorem, and the second law
David Wolpert, Carlo Rovelli, Jordan Scharnhorst
https://arxiv.org/abs/2507.10959

Disentangling Boltzmann brains, the time-asymmetry of memory, the H theorem, and the second law
Are you, with your perceptions, memories and observational data, a Boltzmann brain, i.e., a statistical fluctuation out of the thermal equilibrium of the universe? Arguments are given in the literature for and against taking this hypothesis seriously. Complicating these analyses have been the many subtle - and very often implicit - entanglements between related arguments that have been given for the past hypothesis, the second law, and even Bayesian inference of the reliability of experimental …

A Unified Framework from Boltzmann Transport to Proton Treatment Planning
Andreas E. Kyprianou, Aaron Pim, Tristan Pryer
https://arxiv.org/abs/2508.10596 https://

A Unified Framework from Boltzmann Transport to Proton Treatment Planning
This work develops a rigorous mathematical formulation of proton transport by integrating both deterministic and stochastic perspectives. The deterministic framework is based on the Boltzmann-Fokker-Planck equation, formulated as an operator equation in a suitable functional setting. The stochastic approach models proton evolution via a track-length parameterised diffusion process, whose infinitesimal generator provides an alternative description of transport. A key result is the duality betw…

A Minimalist Physics-Informed Model for Predicting Extreme Conflict Fatalities
Yair Neuman, Yochai Cohen
https://arxiv.org/abs/2507.11576 https://

A Minimalist Physics-Informed Model for Predicting Extreme Conflict Fatalities
The complexity of armed conflicts is expressed in the number of fatalities that may span several orders of magnitude. This study presents a minimalist, physics-informed approach to estimating the likelihood of extreme conflict fatalities at the country level of analysis using Bayesian modeling and energy-based dynamics. Leveraging the Boltzmann distribution to construct a Dirichlet prior, we formulate a predictive measure that captures the underlying entropy and energy states of conflict severi…

Energy-Weighted Flow Matching: Unlocking Continuous Normalizing Flows for Efficient and Scalable Boltzmann Sampling
Niclas Dern, Lennart Redl, Sebastian Pfister, Marcel Kollovieh, David L\"udke, Stephan G\"unnemann
https://arxiv.org/abs/2509.03726

Energy-Weighted Flow Matching: Unlocking Continuous Normalizing Flows for Efficient and Scalable Boltzmann Sampling
Sampling from unnormalized target distributions, e.g. Boltzmann distributions $μ_{\text{target}}(x) \propto \exp(-E(x)/T)$, is fundamental to many scientific applications yet computationally challenging due to complex, high-dimensional energy landscapes. Existing approaches applying modern generative models to Boltzmann distributions either require large datasets of samples drawn from the target distribution or, when using only energy evaluations for training, cannot efficiently leverage the e…

Perfectly transparent boundary conditions and wave propagation in lattice Boltzmann schemes
Thomas Bellotti (EM2C)
https://arxiv.org/abs/2509.10066 https://

Perfectly transparent boundary conditions and wave propagation in lattice Boltzmann schemes
Systems of N = 1, 2, . . . first-order hyperbolic conservation laws feature N undamped waves propagating at finite speeds. On their own hand, multi-step Finite Difference and lattice Boltzmann schemes with q = N + 1, N + 2, . . . unknowns involve N ''physical'' waves, which are aimed at being as closely-looking as possible to the ones of the PDEs, and q-N ''numerical-spurious-parasitic'' waves, which are subject to their own speed of propagation, and either damped or undamped. The whole picture…

Fokker-Planck equation for the Brownian motion in the post-Newtonian approximation
Gilberto M. Kremer
https://arxiv.org/abs/2507.11082 https://

Fokker-Planck equation for the Brownian motion in the post-Newtonian approximation
A mixture of light-gas particles and Brownian heavy particles is analyzed within the framework of a post-Newtonian Boltzmann equation to determine the Fokker-Planck equation for the Brownian motion. For each species, the equilibrium distribution function refers to the corresponding post-Newtonian Maxwell-Jüttner distribution function. The expressions for the friction viscous coefficient in the first and second post-Newtonian approximations are determined, and we show their dependence on the co…

Global dynamical stability for KMS-states
Heide Narnhofer
https://arxiv.org/abs/2508.10728 https://arxiv.org/pdf/2508.10728

Global dynamical stability for KMS-states
The Hugenholz-Boltzmann-evolution is generalized to strongly interacting systems on the lattice. Under appropriate assumptions states stable under this evolution are shown to satify the KMS-condition. How far these assumptions are reasonable is discussed.

Replaced article(s) found for physics.hist-ph. https://arxiv.org/list/physics.hist-ph/new
[1/1]:
- Disentangling Boltzmann brains, the time-asymmetry of memory, the H theorem, and the second law
David Wolpert, Carlo Rovelli, Jordan Scharnhorst

Learning and composing of classical music using restricted Boltzmann machines
Mutsumi Kobayashi, Hiroshi Watanabe
https://arxiv.org/abs/2509.04899 https://…

Learning and composing of classical music using restricted Boltzmann machines
Recently, software has been developed that uses machine learning to mimic the style of a particular composer, such as J. S. Bach. However, since such software often adopts machine learning models with complex structures, it is difficult to analyze how the software understands the characteristics of the composer's music. In this study, we adopted J. S. Bach's music for training of a restricted Boltzmann machine (RBM). Since the structure of RBMs is simple, it allows us to investigate the interna…

Lagrangian entropic lattice Boltzmann method for Courant-free supersonic compressible flow simulation
Woohyuk Noh, Changhoon Lee
https://arxiv.org/abs/2508.06911 https://…

Lagrangian entropic lattice Boltzmann method for Courant-free supersonic compressible flow simulation
This work presents the Lagrangian entropic lattice Boltzmann method (LELBM), a novel framework for supersonic lattice Boltzmann method that surpasses traditional restrictions on velocity, temperature, viscosity, and memory, resulting in stable and efficient Courant-free LBM formulation, while still maintaining explicit time stepping. A regularized central moment collision method coupled with a double-distribution function (DDF) that considers internal degrees of freedom enabled the precise cont…

Boltzmann Thermometry at Cryogenic Temperatures Exploiting Stark Sublevels in Er$^{3 }$/Yb$^{3 }$-Codoped Yttrium Oxide Nanoparticles
Thomas Possmayer, Allison R. Pessoa, Jefferson A. O. Galindo, Luiz F. dos Santos, Rog\'eria R. Gon\c{c}alves, Anderson M. Amaral, Leonardo de S. Menezes
https://arxiv.org/abs/2508.07320

Boltzmann Thermometry at Cryogenic Temperatures Exploiting Stark Sublevels in Er$^{3+}$/Yb$^{3+}$-Codoped Yttrium Oxide Nanoparticles
The development of reliable luminescent nanothermometers for cryogenic applications is essential for advancing quantum technologies, superconducting systems, and other fields that require precise, high-spatial-resolution temperature monitoring. Lanthanide-doped systems are vastly employed to this purpose, and typically perform optimally at or above room temperature when manifold-to-manifold transitions are used. In this work we exploit individual Stark sublevels to demonstrate an optical thermo…

An entropy formula for the Deep Linear Network
Govind Menon, Tianmin Yu
https://arxiv.org/abs/2509.09088 https://arxiv.org/pdf/2509.09088

An entropy formula for the Deep Linear Network
We study the Riemannian geometry of the Deep Linear Network (DLN) as a foundation for a thermodynamic description of the learning process. The main tools are the use of group actions to analyze overparametrization and the use of Riemannian submersion from the space of parameters to the space of observables. The foliation of the balanced manifold in the parameter space by group orbits is used to define and compute a Boltzmann entropy. We also show that the Riemannian geometry on the space of obs…

A second-order volumetric boundary treatment for the lattice Boltzmann method
Kaj Hoefnagel, Damiano Casalino, Steven Hulshoff, Frits de Prenter
https://arxiv.org/abs/2509.05035

A second-order volumetric boundary treatment for the lattice Boltzmann method
A new volumetric-type boundary treatment is introduced for the lattice Boltzmann method. Populations are projected onto a discontinuous piecewise linear basis and streamed using an exact geometrical mapping. The method is implemented in 2D for convex, stationary geometries. Stability is verified through a novel analysis tool based on the eigenvalues of the streaming operation. A convergence rate of $\geq2$ is achieved, indicating improved accuracy over precursor methods. For flow around a 2D ai…

Diabatic quantum annealing for training energy-based generative models
Gilhan Kim, Ju-Yeon Ghym, Daniel K. Park
https://arxiv.org/abs/2509.09374 https://ar…

Diabatic quantum annealing for training energy-based generative models
Energy-based generative models, such as restricted Boltzmann machines (RBMs), require unbiased Boltzmann samples for effective training. Classical Markov chain Monte Carlo methods, however, converge slowly and yield correlated samples, making large-scale training difficult. We address this bottleneck by applying the analytic relation between annealing schedules and effective inverse temperature in diabatic quantum annealing. By implementing this prescription on a quantum annealer, we obtain tem…

Mono and Polyauxic Growth Kinetic Models
Gustavo Mockaitis
https://arxiv.org/abs/2507.05960 https://arxiv.org/pdf/2507.05960

Mono and Polyauxic Growth Kinetic Models
Accurate modeling of microbial growth curves is essential for understanding and optimizing bioprocesses in biotechnology and environmental engineering. While classical monoauxic models such as Monod, Boltzmann, and Gompertz are widely used, they often lack biological interpretability or fail to capture the complex, multiphasic growth patterns observed in systems with mixed substrates or microbial communities. This paper presents a methodological framework for reparametrizing the Boltzmann and G…

Photonic restricted Boltzmann machine for content generation tasks
Li Luo, Yisheng Fang, Wanyi Zhang, Zhichao Ruan
https://arxiv.org/abs/2508.20472 https://

Photonic restricted Boltzmann machine for content generation tasks
The restricted Boltzmann machine (RBM) is a neural network based on the Ising model, well known for its ability to learn probability distributions and stochastically generate new content. However, the high computational cost of Gibbs sampling in content generation tasks imposes significant bottlenecks on electronic implementations. Here, we propose a photonic restricted Boltzmann machine (PRBM) that leverages photonic computing to accelerate Gibbs sampling, enabling efficient content generation…

Global solutions in $L^{p}_{v}L^{\infty}_{x}$ for the Boltzmann equation in bounded domains
Dingqun Deng, Jong-in Kim, Donghyun Lee
https://arxiv.org/abs/2508.05985 https://

Global solutions in $L^{p}_{v}L^{\infty}_{x}$ for the Boltzmann equation in bounded domains
The existence theory for solutions to the Boltzmann equation in bounded domains has primarily been developed within uniformly bounded function classes, such as $L^{\infty}_{x,v}$, as in [Duan-Huang-Wang-Yang,2017], [Duan-Wang,2019], [Guo,2010]. In this paper, we investigate solutions in relaxed function spaces $L^{p}_{v}L^\infty_{x}$ for the initial-boundary value problem of the Boltzmann equation in bounded domains. We consider the case of hard potential under diffuse reflection boundary condi…

Bias in the tensor-to-scalar ratio from self-interacting dark radiation
Nahuel Mir\'on-Granese, Claudia G. Sc\'occola
https://arxiv.org/abs/2509.10607 https://

Bias in the tensor-to-scalar ratio from self-interacting dark radiation
We investigate the cosmological imprint of self-interacting dark radiation (DR) on the primordial $B$-mode angular power spectrum and its impact on the estimation of the tensor-to-scalar ratio $r$. We consider a minimal model in which DR is described as an effectively massless axion-like particle with quartic self-interactions. These interactions are incorporated into the Einstein-Boltzmann equations using the relaxation time approximation and implemented in the $\texttt{CLASS}$ code. We show t…

Discrete Boltzmann distributions via multisets and their coefficients
Bart Jacobs
https://arxiv.org/abs/2507.05719 https://arxiv.org/…

Discrete Boltzmann distributions via multisets and their coefficients
This paper investigates the combinatorics that gives rise to the Boltzmann probability distribution. Despite being one of the most important distributions in physics and other fields of science, the mathematics of the underlying model of particles at different energy levels is underexplored. This paper gives a reconstruction, using multisets with fixed sums as mathematical representations. Counting (the coefficients of) such multisets gives a general description of binomial, trinomial, quadrino…

Non-integrability of n-centre billiards
Stefano Baranzini
https://arxiv.org/abs/2508.07078 https://arxiv.org/pdf/2508.07078

Non-integrability of n-centre billiards
We investigate a class of mechanical billiards, where a particle moves in a planar region under the influence of an n-centre potential and reflects elastically on a straight wall. Motivated by Boltzmann's original billiard model we explore when such systems fail to be integrable. We show that for any positive energy, if there are at least two centres and the wall is placed sufficiently far away, the billiard dynamics is necessarily non-integrable and exhibits chaotic behaviour. In the classical…

An Enthalpy-Based Unified Lattice Boltzmann Flux Solver for Liquid Solidification
Jinxiang Zhou, Liming Yang, Yaping Wang, Jie Wu, Xiaodong Niu
https://arxiv.org/abs/2507.03366

An Enthalpy-Based Unified Lattice Boltzmann Flux Solver for Liquid Solidification
An enthalpy-based uniform lattice Boltzmann flux solver (EULBFS) is proposed in this paper for simulating liquid solidification, incorporating the effects of volume expansion and shrinkage caused by density differences between liquid and solid phases. The proposed solver first establishes the relationships between the macroscopic governing equations and mesoscopic formal equations that describe the temperature, flow, and phase fields. The macroscopic governing equations are then discretized by …

Restricted Boltzmann machine as a probabilistic Enigma
Bin Chen, Weichao Yu
https://arxiv.org/abs/2507.17236 https://arxiv.org/pdf/2507.17236

Restricted Boltzmann machine as a probabilistic Enigma
We theoretically propose a symmetric encryption scheme based on Restricted Boltzmann Machines that functions as a probabilistic Enigma device, encoding information in the marginal distributions of visible states while utilizing bias permutations as cryptographic keys. Theoretical analysis reveals significant advantages including factorial key space growth through permutation matrices, excellent diffusion properties, and computational complexity rooted in sharp P-complete problems that resist qu…

Direct numerical simulations of the supersonic Taylor--Green vortex via the Boltzmann equation
Tarik Dzanic, Will Trojak, Luigi Martinelli
https://arxiv.org/abs/2507.07213

Direct numerical simulations of the supersonic Taylor--Green vortex via the Boltzmann equation
We explore the dynamics of the three-dimensional compressible Taylor--Green vortex from the perspective of kinetic theory by directly solving the six-dimensional Boltzmann equation. This work studies the connections between molecular-scale information encoded in the high-dimensional distribution function (e.g., molecular entropy measures) and macroscopic turbulent flow characteristics. We present high-order direct numerical simulations at Mach numbers of $0.5$ to $1.25$ and Reynolds numbers of …

Crosslisted article(s) found for physics.med-ph. https://arxiv.org/list/physics.med-ph/new
[1/1]:
- A Unified Framework from Boltzmann Transport to Proton Treatment Planning
Andreas E. Kyprianou, Aaron Pim, Tristan Pryer

Classical-to-Quantum Crossover in 2D TMD Field-Effect Transistors: A First-Principles Study via Sub-10 nm Channel Scaling Beyond the Boltzmann Tyranny
Yu-Chang Chen, Ken-Ming Lin
https://arxiv.org/abs/2508.02380

Classical-to-Quantum Crossover in 2D TMD Field-Effect Transistors: A First-Principles Study via Sub-10 nm Channel Scaling Beyond the Boltzmann Tyranny
Two-dimensional transition metal dichalcogenides present compelling prospects for next-generation low-power and high-frequency field-effect transistors. However, scaling 2D TMD FETs into the sub-10 nm regime remains challenging due to technical complexity. Moreover, short-channel effects in this length scale are not yet fully understood. In this work, we investigate the transport properties of 2D TMD nanojunctions with channel lengths from 12 down to 3 nm, using first-principles calculations th…

CLAPP: The CLASS LLM Agent for Pair Programming
Santiago Casas, Christian Fidler, Boris Bolliet, Francisco Villaescusa-Navarro, Julien Lesgourgues
https://arxiv.org/abs/2508.05728

CLAPP: The CLASS LLM Agent for Pair Programming
We introduce CLAPP (CLASS LLM Agent for Pair Programming), an interactive AI assistant designed to support researchers working with the Einstein-Boltzmann solver CLASS. CLAPP leverages large language models (LLMs) and domain-specific retrieval to provide conversational coding support for CLASS-answering questions, generating code, debugging errors, and producing plots. Its architecture combines multi-agent LLM orchestration, semantic search across CLASS documentation, and a live Python executio…

An em algorithm for quantum Boltzmann machines
Takeshi Kimura, Kohtaro Kato, Masahito Hayashi
https://arxiv.org/abs/2507.21569 https://arxiv.org/pdf/2507.2…

An em algorithm for quantum Boltzmann machines
We develop a quantum version of the em algorithm for training quantum Boltzmann machines. The em algorithm is an information-geometric extension of the well-known expectation-maximization (EM) algorithm, offering a structured alternative to gradient-based methods with potential advantages in stability and convergence. We implement the algorithm on a semi-quantum restricted Boltzmann machine, where quantum effects are confined to the hidden layer. This structure enables analytical update rules w…

Optimal $C^{\frac{1}{2}}$ regularity of the Boltzmann equation in non-convex domains
Gayoung An, Donghyun Lee
https://arxiv.org/abs/2507.07353 https://

Optimal $C^{\frac{1}{2}}$ regularity of the Boltzmann equation in non-convex domains
Regularity of the Boltzmann equation, particularly in the presence of physical boundary conditions, heavily relies on the geometry of the boundaries. In the case of non-convex domains with specular reflection boundary conditions, the problem remained outstanding until recently due to the severe singularity of billiard trajectories near the grazing set, where the trajectory map is not differentiable. This challenge was addressed in [32], where $C^{\frac{1}{2}-}_{x,v}$ Hölder regularity was prov…

Investigation of D-Wave quantum annealing for training Restricted Boltzmann Machines and mitigating catastrophic forgetting
Abdelmoula El-Yazizi, Yaroslav Koshka
https://arxiv.org/abs/2508.15697

Investigation of D-Wave quantum annealing for training Restricted Boltzmann Machines and mitigating catastrophic forgetting
Modest statistical differences between the sampling performances of the D-Wave quantum annealer (QA) and the classical Markov Chain Monte Carlo (MCMC), when applied to Restricted Boltzmann Machines (RBMs), are explored to explain, and possibly address, the absence of significant and consistent improvements in RBM trainability when the D-Wave sampling was used in previous investigations. A novel hybrid sampling approach, combining the classical and the QA contributions, is investigated as a prom…

Precision calculation of $N_{\text{eff}}$ with Neutrino Direct Simulation Monte Carlo
Oleksii Ihnatenko, Maksym Ovchynnikov
https://arxiv.org/abs/2508.08379 https://

Precision calculation of $N_{\text{eff}}$ with Neutrino Direct Simulation Monte Carlo
Neutrino Direct Simulation Monte Carlo approach ($ν$DSMC) is a method of solving the neutrino Boltzmann equation in the Early Universe, proposed to study the evolution of neutrinos under various cosmological setups. We formulate a complete $ν$DSMC solver, incorporating the effects of the electron mass, neutrino oscillations, and quantum corrections to the thermodynamics of the electromagnetic plasma. We then apply it for performing precise calculations of neutrino decoupling in the standard c…

Burnett-level multi-relaxation-time central-moment discrete Boltzmann modeling of reactive flows
Qingbin Wu, Chuandong Lin, Huilin Lai
https://arxiv.org/abs/2507.03877

Burnett-level multi-relaxation-time central-moment discrete Boltzmann modeling of reactive flows
A multi-relaxation-time central-moment discrete Boltzmann method (CDBM) is developed for compressible reactive flows, incorporating the effects of chemical reactions. The Chapman--Enskog multiscale analysis demonstrates that the model recovers the Burnett equations in the hydrodynamic limit, with tunable specific heat ratios and Prandtl numbers. Within the CDBM framework, a unified Boltzmann equation governs the evolution of hydrodynamic variables, thermodynamic quantities, and higher-order cen…

Effectiveness of parton cascade in solving the relativistic Boltzmann equation in a box
Todd Mendenhall, Zi-Wei Lin
https://arxiv.org/abs/2507.23107 https://

Effectiveness of parton cascade in solving the relativistic Boltzmann equation in a box
We benchmark the ZPC parton cascade with an exact analytical solution of the relativistic Boltzmann equation for a homogeneous and massless gas with a constant and isotropic elastic cross section. We measure the accuracy of ZPC with the relative mean deviation between its momentum distribution and the exact solution. We use two generalized collision schemes to further improve the accuracy of ZPC over the recent $t$-minimum collision scheme. We find that ZPC can reproduce very well the time evol…

Vibrational frequencies and stark tuning rate with continuum electro-chemical models and grand canonical density functional theory
Mouyi Weng, Nic\'ephore Bonnet, Oliviero Andreussi, Nicola Marzari
https://arxiv.org/abs/2509.10307

Vibrational frequencies and stark tuning rate with continuum electro-chemical models and grand canonical density functional theory
Simulating electrochemical interfaces using density functional theory (DFT) requires incorporating the effects of electrochemical potential. The electrochemical potential acts as a new degree of freedom that can effectively tune DFT results as electrochemistry does. Typically, this is implemented by adjusting the number of electrons on the solid surface within the Kohn-Sham (KS) equation, under the framework of an implicit solvent model and the Poisson-Boltzmann equation (PB equation), thereby …

Replaced article(s) found for math.GR. https://arxiv.org/list/math.GR/new
[1/1]:
- On the origin of the Boltzmann distribution
Fedor Sandomirskiy, Omer Tamuz
ht…

On Modeling and Solving the Boltzmann Equation
Liliane Basso Barichello
https://arxiv.org/abs/2508.13232 https://arxiv.org/pdf/2508.13232

On Modeling and Solving the Boltzmann Equation
The Boltzmann equation has been a driving force behind significant mathematical research over the years. Its challenging theoretical complexity, combined with a wide variety of current scientific and technological problems that require numerical simulations based on this model, justifies such interest. This work provides a brief overview of studies and advances related to the solution of the linear Boltzmann equation in one- and two-dimensional spatial dimensions. In particular, relevant aspect…

The spontaneous Nernst coefficient of ferromagnets from the interplay of electron scattering and Berry curvature
Vittorio Basso, Adriano Di Pietro, Alessandro Sola
https://arxiv.org/abs/2508.08756

The spontaneous Nernst coefficient of ferromagnets from the interplay of electron scattering and Berry curvature
We employ the Boltzmann transport approach to derive the spontaneous Nernst coefficient for ferromagnetic metals, explicitly treating the transverse current density due to Berry curvature as a Fermi surface property. We find that the spontaneous Nernst coefficient is proportional to the inverse of the scattering time constant, implying that efficient spontaneous Nernst materials should exhibit relatively strong scattering, a stark contrast to ordinary Nernst materials. Furthermore, we establish…

Energy Efficient p-Circuits for Generative Neural Networks
Lakshmi A. Ghantasala, Ming-Che Li, Risi Jaiswal, Archisman Ghosh, Behtash Behin-Aein, Joseph Makin, Shreyas Sen, Supriyo Datta
https://arxiv.org/abs/2507.07763

Energy Efficient p-Circuits for Generative Neural Networks
A p-circuit comprising a network of $N$ p-bits can generate samples from a probability distribution with $2^N$ possibilities just like a network of q-bits, though there are interesting fundamental differences. A p-bit is essentially a binary stochastic neuron used in Boltzmann machines which involve the repeated application of a specific elementary operation, whereby each p-bit looks at the state of 'n' other p-bits, computes the probability for being $0$ or $1$, and chooses its next state acco…

Hierarchical Maximum Entropy via the Renormalization Group
Amir R. Asadi
https://arxiv.org/abs/2509.01424 https://arxiv.org/pdf/2509.01424

Hierarchical Maximum Entropy via the Renormalization Group
Hierarchical structures, which include multiple levels, are prevalent in statistical and machine-learning models as well as physical systems. Extending the foundational result that the maximum entropy distribution under mean constraints is given by the exponential Gibbs-Boltzmann form, we introduce the framework of "hierarchical maximum entropy" to address these multilevel models. We demonstrate that Pareto optimal distributions, which maximize entropies across all levels of hierarchical transf…

Relativistic Dissipative Magnetohydrodynamics for accretion disks
Khwahish Kushwah, Gabriel S. Denicol
https://arxiv.org/abs/2509.02935 https://arxiv.org/p…

Relativistic Dissipative Magnetohydrodynamics for accretion disks
We derive a relativistic magnetohydrodynamics (RMHD) theory for a dilute electron-ion gas governed by the Boltzmann-Vlasov equation, using the method of moments. This yields an extended MHD framework beyond standard astrophysical formulations, which typically include only the shear-stress component parllel to the magnetic field. We analyze our framework in the linear regime and show that it leads to the firehose instability when the bakground longitudinal pressure becomes large. In these extrem…

Efficient numerical methods for the uncertain Boltzmann equation based on a hybrid solver
Yiwen Lin, Liu Liu
https://arxiv.org/abs/2507.20316 https://arxiv…

Efficient numerical methods for the uncertain Boltzmann equation based on a hybrid solver
In this work, we propose and compare several approaches to solve the Boltzmann equation with uncertain parameters, including multi-level Monte Carlo and multi-fidelity methods that employ an asymptotic-preserving-hybrid (APH) scheme (Filbet and Rey, 2015) for the deterministic Boltzmann model. By constructing a hierarchy of models from finer to coarser meshes in phase space for the APH scheme and adopting variance reduction techniques, the MLMC method is able to allocate computational resources…

PDE-constrained optimal control of a leader-follower opinion formation model
Bertram D\"uring, Oliver Wright
https://arxiv.org/abs/2508.21674 https://…

PDE-constrained optimal control of a leader-follower opinion formation model
We consider the PDE-constrained optimal control of a leader-follower kinetic opinion formation model, with a Fokker-Planck-type system of partial differential equations as a state constraint. We derive the Boltzmann-type and Fokker-Planck-type systems of equations associated with the controlled leader-follower opinion formation model. In a function space setting we derive first-order optimality conditions associated with the PDE-constrained optimal control problem, yielding an optimality system…

Large-Scale Simulations of Turbulent Flows using Lattice Boltzmann Methods on Heterogeneous High Performance Computers
Adrian Kummerl\"ander, Fedor Bukreev, Yuji Shimojima, Shota Ito, Mathias J. Krause
https://arxiv.org/abs/2506.21804

Large-Scale Simulations of Turbulent Flows using Lattice Boltzmann Methods on Heterogeneous High Performance Computers
Current GPU-accelerated supercomputers promise to enable large-scale simulations of turbulent flows. Lattice Boltzmann Methods (LBM) are particularly well-suited to fulfilling this promise due to their intrinsic compatibility with highly parallel execution on both SIMD CPUs and GPUs. A novel LBM scheme for wall-modeled LES in complex geometries is described with a special focus on the efficient implementation in the open source LBM framework OpenLB. Detailed scalability results are provided for…

Sublimation and deposition at a solid sphere in the presence of a non-condensable gas
Denize Kalempa, Felix Sharipov, Irina Graur
https://arxiv.org/abs/2507.10858

Sublimation and deposition at a solid sphere in the presence of a non-condensable gas
The sublimation/deposition process at a solid sphere of argon into its vapor in the presence of helium as a background gas is modeled applying the linearized Boltzmann equation, in which the McCormack model is employed for the collisional term. The Onsager coefficients determining the mass and energy flow rates at the interface are calculated over a wide range of rarefaction parameter and for some values of molar fraction of the background gas in the mixture. Moreover, two values for the temper…

Stable Islands of Weak Gravity
Linus Thummel, Benjamin Bose, Alkistis Pourtsidou
https://arxiv.org/abs/2508.05729 https://arxiv.org/pdf/2508.05729

Stable Islands of Weak Gravity
We present an exploration of the phenomenology of Horndeski gravity, focusing on regimes that produce weak gravity compared to General Relativity. This letter introduces a novel method to generate models of modified gravity theories that produce a specific observational behaviour while fulfilling stability criteria, without imposing a fixed parametrisation. We start from the inherently stable basis of linear Horndeski theory, implemented in the recently released Einstein-Boltzmann solver mochi_…

A geometric formulation of GENERIC stochastic differential equations
Mark A. Peletier, Marcello Seri
https://arxiv.org/abs/2509.09566 https://arxiv.org/pdf…

A geometric formulation of GENERIC stochastic differential equations
We propose a coordinate-invariant geometric formulation of the GENERIC stochastic differential equation, unifying reversible Hamiltonian and irreversible dissipative dynamics within a differential-geometric framework. Our construction builds on the classical GENERIC formalism, extending it to manifolds by introducing a degenerate Poisson structure, a degenerate co-metric, and a volume form satisfying a unimodularity condition. The resulting equation preserves a particular Boltzmann-type measure…

Replaced article(s) found for math.AP. https://arxiv.org/list/math.AP/new
[2/2]:
- A fast Fourier spectral method for the linearized Boltzmann collision operator
Tianai Yin, Zhenning Cai, Yanli Wang

Boltzmann-Ginzburg-Landau theory for autochemotaxis of active rod-like particles
Shun Sakurai, Nariya Uchida
https://arxiv.org/abs/2506.18263 https://

Boltzmann-Ginzburg-Landau theory for autochemotaxis of active rod-like particles
We investigate the interplay between chemotaxis and alignment interactions in active rod-like particles, such as E. coli and Janus rods. Starting from a discrete model of self-propelled rods with chemotactic responses, we employ a Boltzmann-Ginzburg-Landau (BGL) approach to derive coarse-grained dynamical equations for the density, polar and nematic orientational order parameters, and the concentration field of the chemoattractant. We perform a linear stability analysis for fluctuations around …

Quantum Boltzmann Machines using Parallel Annealing for Medical Image Classification
Dani\"elle Schuman, Mark V. Seebode, Tobias Rohe, Maximilian Balthasar Mansky, Michael Schroedl-Baumann, Jonas Stein, Claudia Linnhoff-Popien, Florian Krellner
https://arxiv.org/abs/2507.14116

Quantum Boltzmann Machines using Parallel Annealing for Medical Image Classification
Exploiting the fact that samples drawn from a quantum annealer inherently follow a Boltzmann-like distribution, annealing-based Quantum Boltzmann Machines (QBMs) have gained increasing popularity in the quantum research community. While they harbor great promises for quantum speed-up, their usage currently stays a costly endeavor, as large amounts of QPU time are required to train them. This limits their applicability in the NISQ era. Following the idea of Noè et al. (2024), who tried to allev…

Unified Semiclassical Theory of Nonlinear Hall Effect:Bridging Ballistic and Diffusive Transport Regime
Xinyu Liu, Haozhi Liao, Guangyun Qi, Hao Geng, Li Sheng, Dingyu Xing
https://arxiv.org/abs/2508.07445

Unified Semiclassical Theory of Nonlinear Hall Effect:Bridging Ballistic and Diffusive Transport Regime
The nonlinear Hall effect has attracted considerable attention and undergone extensive investigation in recent years. However, theoretical studies addressing size-dependent effects remain largely unexplored. In this work, we establish a unified semiclassical framework based on the Boltzmann transport equation, incorporating generalized boundary conditions to bridge the ballistic and diffusive transport regimes. Our analysis reveals that the nonlinear Hall effect arises from the combined action …

Gas dynamic equations from Boltzmann to Navier-Stokes scales
Zhaoli Guo, Kun Xu, Yajun Zhu
https://arxiv.org/abs/2508.07189 https://arxiv.org/pdf/2508.0718…

Gas dynamic equations from Boltzmann to Navier-Stokes scales
Understanding the dynamics of nonequilibrium gas flows spanning multiple flow regimes is challenging due to the breakdown of scale separation. In this work, we propose a kinetic framework that captures the transport of molecules under varying collision behaviors within a given observation timescale $h$. Within this framework, gas molecules in the system are classified into three types over the time interval $0\le t

The non-isothermal Maxwell-Stefan asymptotics of the multi-species Boltzmann equations
Xinqiu Chen, Ning Jiang, Yi-Long Luo
https://arxiv.org/abs/2508.03311 https://

The non-isothermal Maxwell-Stefan asymptotics of the multi-species Boltzmann equations
We study the convergence from the multi-species Boltzmann equations to the non-isothermal Maxwell-Stefan system. The global-in-time well-posedness of the Maxwell-Stefan system is first established. The solution is utilized as the fluid quantities to construct a local Maxwellian vector. The Maxwell-Stefan system can be derived from the multi-species Boltzmann equations under diffusive scaling by adding a relation on the total concentration. Different with the classical hydrodynamic limits of the…

Momentum-Resolved Relaxation-Time Approach for Size-Dependent Conductivity in Anisotropic Metallic Films
YoungJun Lee, Jin Soo Lee, Seungjun Lee, Seoung-Hun Kang, Young-Kyun Kwon
https://arxiv.org/abs/2508.08622

Momentum-Resolved Relaxation-Time Approach for Size-Dependent Conductivity in Anisotropic Metallic Films
Shrinking CMOS interconnect dimensions to the nanometer scale intensifies electron scattering at surfaces, interfaces, and grain boundaries, causing severe conductivity loss and challenging copper-based designs. Here we present a momentum-resolved relaxation time framework that integrates density functional theory with the semiclassical Boltzmann transport equation to predict size-dependent resistivity in metallic thin films. Electron phonon interactions are computed from first principles, and …

Crosslisted article(s) found for physics.flu-dyn. https://arxiv.org/list/physics.flu-dyn/new
[1/1]:
- IGA-LBM: Isogeometric lattice Boltzmann method
Ye Ji, Monica Lacatus, Matthias M\"oller

Unifying Kappa Distribution Models for Non-Equilibrium Space Plasmas: A Superstatistical Approach Based on Moments
Abiam Tamburrini, Sergio Davis, Pablo S. Moya
https://arxiv.org/abs/2509.07927

Unifying Kappa Distribution Models for Non-Equilibrium Space Plasmas: A Superstatistical Approach Based on Moments
From the perspective of non-equilibrium statistical mechanics, modeling the velocity distribution of particles in non-equilibrium, steady-state plasmas presents a significant challenge. Under this context, a family of kappa distributions has been widely used to capture the high-energy tails in space plasmas. These distributions deviate from the canonical Maxwell-Boltzmann statistics and vary significantly in their interpretation of the temperature of an out-of-equilibrium system. In this letter…

CLASS_SZ II: Notes and Examples of Fast and Accurate Calculations of Halo Model, Large Scale Structure and Cosmic Microwave Background Observables
Boris Bolliet, Aleksandra Kusiak, Fiona McCarthy, Alina Sabyr, Kristen Surrao, Jens Chluba, Carmen Embil Villagra, Simone Ferraro, Boryana Hadzhiyska, Dongwon Han, J. Colin Hill, Juan Francisco Mac\'ias-P\'erez, Mathew Madhavacheril, Abhishek Maniyar, Yogesh Mehta, Shivam Pandey, Emmanuel Schaan, Blake Sherwin, Alessio Spurio Mancini…

CLASS_SZ II: Notes and Examples of Fast and Accurate Calculations of Halo Model, Large Scale Structure and Cosmic Microwave Background Observables
These notes are very much work-in-progress and simply intended to showcase, in various degrees of details (and rigour), some of the cosmology calculations that class_sz can do. We describe the class_sz code in C, Python and Jax. Based on the Boltzmann code class, it can compute a wide range of observables relevant to current and forthcoming CMB and Large Scale Structure surveys. This includes galaxy shear and clustering, CMB lensing, thermal and kinetic Sunyaev and Zeldovich observables, Cosmic…

Matrixed-Spectrum Decomposition Accelerated Linear Boltzmann Transport Equation Solver for Fast Scatter Correction in Multi-Spectral CT
Guoxi Zhu, Li Zhang, Zhiqiang Chen, Hewei Gao
https://arxiv.org/abs/2508.20524

Matrixed-Spectrum Decomposition Accelerated Linear Boltzmann Transport Equation Solver for Fast Scatter Correction in Multi-Spectral CT
X-ray scatter has been a serious concern in computed tomography (CT), leading to image artifacts and distortion of CT values. The linear Boltzmann transport equation (LBTE) is recognized as a fast and accurate approach for scatter estimation. However, for multi-spectral CT, it is cumbersome to compute multiple scattering components for different spectra separately when applying LBTE-based scatter correction. In this work, we propose a Matrixed-Spectrum Decomposition accelerated LBTE solver (MSD…

A Formal Derivation of the Thick Spray Model from the Enskog-Boltzmann System
Zhe Chen
https://arxiv.org/abs/2509.05118 https://arxiv.org/pdf/2509.05118

A Formal Derivation of the Thick Spray Model from the Enskog-Boltzmann System
We propose a specific scaling that formally derives the Euler-Vlasov model for thick sprays which is widely adopted in engineering from the Boltzmann-Enskog model. Beyond validating the kinetic-fluid equations underlying this model, we also identify higher-order corrections of the viscous force (of the order of the volume of the dispersed phase), which is neglected due to the incorporation of the volume fraction (void) function. Our approach builds on the work [Laurent Desvillettes, François G…

Oscillating Heat Transfer Prediction in Porous Structures Using Generative AI-Assisted Explainable Machine Learning
Lichang Zhu, Laura Schaefer, Leitao Chen, Ben Xu
https://arxiv.org/abs/2509.11863

Oscillating Heat Transfer Prediction in Porous Structures Using Generative AI-Assisted Explainable Machine Learning
Predicting and interpreting thermal performance under oscillating flow in porous structures remains a critical challenge due to the complex coupling between fluid dynamics and geometric features. This study introduces a data-driven wGAN-LBM-Nested_CV framework that integrates generative deep learning, numerical simulation based on the lattice Boltzmann method (LBM), and interpretable machine learning to predict and explain the thermal behavior in such systems. A wide range of porous structures …

Spectral BBGKY: a scalable scheme for nonlinear Boltzmann and correlation kinetics
Shuai Lu, Shuzhe Shi
https://arxiv.org/abs/2507.14243 https://

Spectral BBGKY: a scalable scheme for nonlinear Boltzmann and correlation kinetics
The Bogoliubov-Born-Green-Kirkwood-Yvon (BBGKY) hierarchy provides a time-reversal-symmetric framework for describing the nonequilibrium evolution of many-body systems. Despite the success of Boltzmann-based numerical approaches, systematically extending beyond this lowest-order truncation to the full nonlinear BBGKY hierarchy remains a major challenge. Moreover, even at the Boltzmann level, accurately treating the nonlinear collision term still presents significant difficulties. Here we propos…

A Bi-fidelity numerical method for velocity discretization of Boltzmann equations
Nicolas Crouseilles, Zhen Hao, Liu Liu
https://arxiv.org/abs/2507.19945 https://

A Bi-fidelity numerical method for velocity discretization of Boltzmann equations
In this paper, we introduce a bi-fidelity algorithm for velocity discretization of Boltzmann-type kinetic equations under multiple scales. The proposed method employs a simpler and computationally cheaper low-fidelity model to capture a small set of significant velocity points through the greedy approach, then evaluates the high-fidelity model only at these few velocity points and to reconstruct a bi-fidelity surrogate. This novel method integrates a simpler collision term of relaxation type in…

Electromagnetic Leptogenesis -- an EFT-Consistent Analysis via Wilson Coefficients I: Low-Scale, Non-Resonant Regime
Rin Takada
https://arxiv.org/abs/2509.07698 https://

Electromagnetic Leptogenesis -- an EFT-Consistent Analysis via Wilson Coefficients I: Low-Scale, Non-Resonant Regime
We analyse electromagnetic leptogenesis within the framework of an effective field theory, where the dynamics is governed by the gauge-invariant dipole operator $O_{NB}$. The Wilson coefficient $C_{NB}$ is matched at one loop and renormalisation-group (RG) evolved to the electroweak scale. After electroweak symmetry breaking we compute flavour-dependent two-body decay widths and CP asymmetries for $N\toν+γ/Z$, and solve the fully flavoured Boltzmann equations. In the $N_1$-dominated regime th…

On Boltzmann Averaging in Ab Initio Thermodynamics
Hendrik H. Heenen, Karsten Reuter
https://arxiv.org/abs/2506.23229 https://arxiv.o…

On Boltzmann Averaging in Ab Initio Thermodynamics
Ab initio thermodynamics is a widespread, computationally efficient approach to predict the stable configuration of a surface in contact with a surrounding (gas or liquid) environment. In a prevalent realization of this approach, this stable configuration is simply equated with the structure in a considered candidate pool that exhibits the lowest surface free energy. Here we discuss the possibility to consider the thermal accessibility of competing, higher-energy configurations through Boltzman…

JAX-LaB: A High-Performance, Differentiable, Lattice Boltzmann Library for Modeling Multiphase Fluid Dynamics in Geosciences and Engineering
Piyush Pradhan, Pierre Gentine, Shaina Kelly
https://arxiv.org/abs/2506.17713

JAX-LaB: A High-Performance, Differentiable, Lattice Boltzmann Library for Modeling Multiphase Fluid Dynamics in Geosciences and Engineering
We present JAX-LaB, a differentiable, Python-based Lattice Boltzmann library for simulating multiphase and multiphysics flows in hydrologic, geologic, and engineered porous media. Built as an extension of the XLB library, JAX-LaB utilizes JAX for computations and offers a performant, hardware-agnostic implementation that integrates seamlessly with machine learning workflows and scales efficiently across CPUs, GPUs, and distributed systems. Multiphase interactions are modeled using the Shan-Chen…

Momentum distribution and correlation of free particles in the Tsallis statistics using conventional expectation value and equilibrium temperature
Masamichi Ishihara
https://arxiv.org/abs/2508.01609

Momentum distribution and correlation of free particles in the Tsallis statistics using conventional expectation value and equilibrium temperature
We applied the Tsallis statistics with the conventional expectation value to a system of free particles, adopting the equilibrium temperature which is often called the physical temperature. The entropic parameter $q$ in the Tsallis statistics is less than one for power-law-like distribution. The well-known relation between the energy and the temperature in the Boltzmann--Gibbs statistics holds in the Tsallis statistics, when the equilibrium temperature is adopted. We derived the momentum distri…

Collective contributions to polarization in political voting
Gavin Rees, Edward D. Lee
https://arxiv.org/abs/2508.02496 https://arxiv.org/pdf/2508.02496

Collective contributions to polarization in political voting
Politics around the world exhibits increasing polarization, demonstrated in part by rigid voting configurations in legislatures. The crux of polarization is separation along a unidimensional ideological axis, but how it emerges is yet partially understood. We refine a powerful class of models from statistical physics, restricted Boltzmann machines, to unify two classes of individual voter preference and voter interaction models. Our model is minimally parameterized, fits voting data well, and h…

Interpolation-supplemented lattice Boltzmann simulation of thermal convection on non-uniform meshes
Ao Xu, Zheng Zhao, Ben-Rui Xu, Li-Sheng Jiang
https://arxiv.org/abs/2509.01099

Interpolation-supplemented lattice Boltzmann simulation of thermal convection on non-uniform meshes
We present a systematic evaluation of an interpolation-supplemented lattice Boltzmann method (ISLBM) for simulating buoyancy-driven thermal convection on non-uniform meshes. The ISLBM extends the standard lattice Boltzmann framework by incorporating quadratic interpolation during the streaming step, enabling flexible mesh refinement near solid boundaries while maintaining algorithmic simplicity and parallel scalability. The method is implemented for a two-dimensional side-heated cavity at high …

Topological Regularization for Force Prediction in Active Particle Suspension with EGNN and Persistent Homology
Sadra Saremi, Amirhossein Ahmadkhan Kordbacheh
https://arxiv.org/abs/2509.06574

Topological Regularization for Force Prediction in Active Particle Suspension with EGNN and Persistent Homology
Capturing the dynamics of active particles, i.e., small self-propelled agents that both deform and are deformed by a fluid in which they move is a formidable problem as it requires coupling fine scale hydrodynamics with large scale collective effects. So we present a multi-scale framework that combines the three learning-driven tools to learn in concert within one pipeline. We use high-resolution Lattice Boltzmann snapshots of fluid velocity and particle stresses in a periodic box as input to t…

Thermal Transport and Application Reassessment of ThSi$_2$N$_4$ Monolayer: From FET Channel to Thermoelectric Material
Maryam Mirzaei Farshmi, Seyedeh Ameneh Bahadori, Zahra Shomali
https://arxiv.org/abs/2507.06356

Thermal Transport and Application Reassessment of ThSi$_2$N$_4$ Monolayer: From FET Channel to Thermoelectric Material
The two-dimensional M$_2$Z$_4$ materials are proposed as suitable replacements for silicon channels in field-effect transistors (FETs). In the present work, the ThSi$_2$N$_4$ monolayer from the family, with the very appropriate electron mobility, is thermally investigated using the non-equilibrium Monte Carlo simulation of the phonon Boltzmann transport equation. The reliability of the MOSFET with the ThSi$_2$N$_4$ channel has been reassessed and determined to be low due to the high maximum tem…

Knudsen number and universal behavior of collective flows in conformal and non-conformal systems
Vincenzo Nugara (Department of Physics and Astronomy, University of Catania, Catania, INFN-Laboratori Nazionali del Sud, Catania, Italy), Nicolas Borghini (Fakult\"at f\"ur Physik, Universit\"at Bielefeld, D-33615 Bielefeld, Germany), Vincenzo Greco (Department of Physics and Astronomy, University of Catania, Catania, INFN-Laboratori Nazionali del Sud, Catania, Italy), Salvat…

Knudsen number and universal behavior of collective flows in conformal and non-conformal systems
We investigate the role of the Knudsen number (Kn) as a scaling parameter governing the emergence of collective behavior in relativistic heavy-ion collisions. Using the Relativistic Boltzmann Transport approach, we explore different initial conditions for both conformal (massless) and non-conformal (massive) systems with a constant specific shear viscosity $η/s$. Observables such as the time evolution of anisotropic flow coefficients collapse onto universal curves for fixed classes of Knudsen …

Multiscale Hilbert expansion and hydrodynamics beyond Navier-Stokes
O. M. Chekmareva, I. B. Chekmarev
https://arxiv.org/abs/2509.02580 https://arxiv.org/pd…

Multiscale Hilbert expansion and hydrodynamics beyond Navier-Stokes
A truncated Hilbert expansion with multiple scales is used to construct asymptotic solution of the linearized one-dimensional Boltzmann equation with small Knudsen number. The freedom ganed by introducing new independent time variables is exploited to eliminate the sources of secular behavior as the time interval increases. The regular gas-dynamic equations then appear as necessary conditions for expansion to be uniformly valid on a long time intervals.

Fisher information for solutions of the Boltzmann equation
Cyril Imbert (DMA)
https://arxiv.org/abs/2509.03045 https://arxiv.org/pdf/2509.03045

Fisher information for solutions of the Boltzmann equation
This note reviews a recent contribution about the Fisher information for the space-homogeneous Boltzmann equation by L. Silvestre, C. Villani and the author (arXiv, 2024). This classical functional from information theory is shown to be nonincreasing along the flow of the non-linear PDE for all physically relevant particle interactions. The proof consists in establishing a new functional inequality on the sphere of Log-Sobolev type. This new a priori estimate on solutions yields global-in-time …

What the Boltzmann money game teaches us about statistical mechanics (and maybe economics)
Dmitrii E. Makarov
https://arxiv.org/abs/2507.22180 https://arxi…

What the Boltzmann money game teaches us about statistical mechanics (and maybe economics)
This note explains why a large class of fair, or reversible "money games", i.e., stochastic models of wealth redistribution among agents, lead to steady states described by canonical and microcanonical distributions. The games considered include, for example, ones where more than two agents can be simultaneously involved in money transfers (similarly to many-body collisions in chemical kinetics) and where amounts transferred between agents are random. At the same time, money games that break ti…

Saddle Hierarchy in Dense Associative Memory
Robin Th\'eriault, Daniele Tantari
https://arxiv.org/abs/2508.19151 https://arxiv.org/pdf/2508.19151

Saddle Hierarchy in Dense Associative Memory
Dense associative memory (DAM) models have been attracting renewed attention since they were shown to be robust to adversarial examples and closely related to state-of-the-art machine learning paradigms, such as the attention mechanisms in transformers and generative diffusion models. We study a DAM built upon a three-layer Boltzmann machine with Potts hidden units, which represent data clusters and classes. Through a statistical mechanics analysis, we derive saddle-point equations that charact…

Strong acoustic phonon suppression leads to ultralow thermal conductivity and enhanced thermoelectric performance in BaCuGdTe$_3$
Jyoti Duhan, Chris Wolverton, Koushik Pal
https://arxiv.org/abs/2507.05831

Strong acoustic phonon suppression leads to ultralow thermal conductivity and enhanced thermoelectric performance in BaCuGdTe$_3$
Excitations and scatterings among the quantized lattice vibrations, i.e., phonons, govern the lattice thermal conductivity ($κ_l$) in crystalline solids. Therefore, effective modulation of $κ_l$ can be achieved through selective manipulation of phonon modes that strongly participate in the heat transport mechanisms. Here, combining accurate first-principles density functional theory calculations and Boltzmann transport theory, we report a layered quaternary chalcogenide semiconductor, BaCuGdT…

Fisher entropic Fokker-Planck model of monatomic rarefied gases
Veronica Montanaro, Lukas Netterdon, Manuel Torrilhon, Hossein Gorji
https://arxiv.org/abs/2509.06610 https://

Fisher entropic Fokker-Planck model of monatomic rarefied gases
Particle-based stochastic approximations of the Boltzmann equation are popular tools for simulations of non-equilibrium gas flows, for which the Navier-Stokes-Fourier equations fail to provide accurate description. However, these numerical methods are computationally demanding, especially in the near-continuum regime, where the collisions become overwhelming. On the other hand, the Fokker-Planck kinetic models offer an efficient alternative, as the binary collisions are described by a diffusive…

Replaced article(s) found for cond-mat.stat-mech. https://arxiv.org/list/cond-mat.stat-mech/new
[2/2]:
- Beyond the Boltzmann equation for weakly coupled quantum fields
Xu-Yao Hu, Vladimir Rosenhaus

Linear viscoelasticity: Mechanics, analysis and approximation
Michael Ortiz
https://arxiv.org/abs/2509.03485 https://arxiv.org/pdf/2509.03485

Linear viscoelasticity: Mechanics, analysis and approximation
The aim of this review is to highlight the connection between well-established physical and mathematical principles as they pertain to the theory of linear elasticity. We begin by examining the physical foundations of Boltzmann and Volterra's hereditary law formalism, and how those principles restrict the form of the hereditary law. We then turn to questions of material stability and continuous dependence on the stress history within the framework of the Lax-Milgram theorem, which we find to se…

Realizability-preserving monolithic convex limiting in continuous Galerkin discretizations of the M1 model of radiative transfer
Paul Moujaes, Dmitri Kuzmin, Christian B\"aumer
https://arxiv.org/abs/2509.07689

Realizability-preserving monolithic convex limiting in continuous Galerkin discretizations of the M1 model of radiative transfer
We discretize the $M_1$ model of radiative transfer using continuous finite elements and propose a tailor-made monolithic convex limiting (MCL) procedure for enforcing physical realizability. The $M_1$ system of nonlinear balance laws for the zeroth and first moments of a probability distribution function is derived from the linear Boltzmann equation and equipped with an entropy-based closure for the second moment. To ensure hyperbolicity and physical admissibility, evolving moments must stay i…

Can cosmic rotation resolve the Hubble tension? Constraints from CMB and large-scale structure
Micol Benetti, David A. Cook, Saulo Carneiro
https://arxiv.org/abs/2508.00759 http…

Can cosmic rotation resolve the Hubble tension? Constraints from CMB and large-scale structure
We investigate a relativistic cosmological model with background rotation, sourced by a non-perfect fluid with anisotropic stress. A modified version of the CLASS Boltzmann code is employed to perform MCMC analyses against Cosmic Microwave Background (CMB) and late-time datasets. The results show that current CMB data constrain the present-day rotation parameter to be negligible. As a consequence, the derived cosmological parameters remain consistent with the standard $Λ$CDM values. In contras…

Hydrodynamic limit from kinetic models with massless electrons to the ionic Euler--Poisson system
Young-Pil Choi, Dowan Koo, Sihyun Song
https://arxiv.org/abs/2508.08482 https:/…

Hydrodynamic limit from kinetic models with massless electrons to the ionic Euler--Poisson system
We study the derivation of ion dynamics, namely, the ionic Euler--Poisson system, from kinetic descriptions. The kinetic framework consists of the ionic Vlasov--Poisson equation coupled with either a nonlinear Fokker--Planck operator or a local alignment term. In both kinetic and fluid models, the massless electrons are assumed to be in thermodynamic equilibrium, leading to an electric potential governed by the Poisson--Boltzmann equation. The exponential nonlinearity in this semilinear ellipti…

Ta2Pd3Te8: A potential candidate of 1D van der Waals stacked thermoelectric materials
Shi Chen, Aijun Hong, Junming Liu
https://arxiv.org/abs/2508.05549 https://

Ta2Pd3Te8: A potential candidate of 1D van der Waals stacked thermoelectric materials
Discovering new thermoelectric (TE) materials is an eternal goal in the TE field. Excellent TE materials have ranged from 3D stacked to 2D stacked bulk. However, the 1D stacked receives little attention due to the scarcity in quantity. In this work, it is predicted that 1D van der Waals (vdW) stacked Ta2Pd3Te8 crystal is a compelling candidate for TE applications by combining first-principles calculations with phonon and electron Boltzmann transport equations and molecular dynamics methods. We …

Replaced article(s) found for physics.comp-ph. https://arxiv.org/list/physics.comp-ph/new
[1/1]:
- GPU-based compressible lattice Boltzmann simulations on non-uniform grids using standard C para...
Christophe Coreixas, Jonas Latt

Asymptotic Analysis of Boundary Layer Solutions to Poisson-Boltzmann Type Equations in General Bounded Smooth Domains
Jhih-Hong Lyu, Tai-Chia Lin
https://arxiv.org/abs/2506.20953 …

Asymptotic Analysis of Boundary Layer Solutions to Poisson-Boltzmann Type Equations in General Bounded Smooth Domains
We study the boundary layer solution to singular perturbation problems involving Poisson-Boltzmann (PB) type equations with a small parameter $ε$ in general bounded smooth domains (including multiply connected domains) under the Robin boundary condition. The PB type equations include the classical PB, modified PB and charge-conserving PB (CCPB) equations, which are mathematical models for the electric potential and ion distributions. The CCPB equations present particular analytical challenges …

Replaced article(s) found for physics.flu-dyn. https://arxiv.org/list/physics.flu-dyn/new
[1/1]:
- A low-Mach phase field-lattice Boltzmann-finite difference model for reactive gas flows propagati...
Reza Namdar, Mohammad Norouzi, Fathollah Varnik

A Nodal Discontinuous Galerkin Method with Low-Rank Velocity Space Representation for the Multi-Scale BGK Model
Andres Galindo-Olarte, Joseph Nakao, Mirjeta Pasha, Jing-Mei Qiu, William Taitano
https://arxiv.org/abs/2508.16564

A Nodal Discontinuous Galerkin Method with Low-Rank Velocity Space Representation for the Multi-Scale BGK Model
A novel hybrid algorithm is presented for the Boltzmann-BGK equation, in which a low-rank decomposition is applied solely in the velocity subspace, while a full-rank representation is maintained in the physical (position) space. This approach establishes a foundation for extending modern low-rank techniques to solve the Boltzmann equation in realistic settings, particularly where structured representations -- such as conformal geometries -- may not be feasible in practical engineering applicati…

$H^s_x$ regularity of solutions to the stationary Boltzmann equation with the incoming boundary condition
Daisuke Kawagoe
https://arxiv.org/abs/2507.18211 https://

$H^s_x$ regularity of solutions to the stationary Boltzmann equation with the incoming boundary condition
We consider the stationary Boltzmann equation with the cross section of the form $B(|v - \tilde{v}, θ|) = B_0 |v - \tilde{v}|^γ\cos θ\sin θ$ for $-3 < γ\leq 1$ in a bounded convex domain under the incoming boundary condition. In this article, we shall show the existence of a solution in a weighted $L^\infty$ space with fractional Sobolev regularity without assuming the positivity of the Gaussian curvature on the boundary. For boundary data sufficiently smooth and close …

Common errors in BoltzTraP-based calculations
{\O}ven A. Grimenes, Kristian Berland
https://arxiv.org/abs/2509.00959 https://arxiv.org/pdf/2509.00959

Common errors in BoltzTraP-based calculations
Boltzmann transport calculations based on band structures computed from first principles play an important role in modern thermoelectric materials research. Among available codes, the \textsc{BoltzTraP} code is the most widely adopted, but many recent studies contain systematic mistakes. We identify three error modes: (1) inserting the electronic thermal conductivity at zero electric field, $κ_0$, in place of the electronic thermal conductivity at zero electric current, $κ_e$, (2) computing t…

Incompressible Euler limit from the Boltzmann equation with Maxwell reflection boundary condition in the half-space
Ning Jiang, Chao Wang, Yulong Wu, Zhifei Zhang
https://arxiv.org/abs/2506.18420

Incompressible Euler limit from the Boltzmann equation with Maxwell reflection boundary condition in the half-space
In this paper, we rigorously justify the incompressible Euler limit of the Boltzmann equation with general Maxwell reflection boundary condition in the half-space. The accommodation coefficient $α\in (0,1]$ is assumed to be $O(1)$. Our construction of solutions includes the interior fluid part and Knudsen-Prandtl coupled boundary layers. The corresponding solutions to the nonlinear Euler and nonlinear Prandtl systems are taken to be shear flows. Due to the presence of the nonlinear Prandtl lay…

Global behavior of the energy to the hyperbolic equation of viscoelasticity with combined power-type nonlinearities
Haiyang Lin, Jinqi Yan, Bo You
https://arxiv.org/abs/2509.08462

Global behavior of the energy to the hyperbolic equation of viscoelasticity with combined power-type nonlinearities
The main objective of this manuscript is to investigate the global behavior of the solutions to the viscoelastic wave equation with a linear memory term of Boltzmann type, and a nonlinear damping modeling friction, as well as a supercritical source term which is a combined power-type nonlinearities. The global existence of the solutions is obtained provided that the energy sink dominates the energy source in an appropriate sense. In more general scenarios, we prove the global existence of the s…

Practical Kinetic Models for Dense Fluids
Ilya Karlin, Seyed Ali Hosseini
https://arxiv.org/abs/2508.00577 https://arxiv.org/pdf/2508.00577

Practical Kinetic Models for Dense Fluids
Nonlinear idempotent operator instead of a linear projection is introduced to derive kinetic models for dense fluids. A new lattice Boltzmann model for compressible two-phase flow is derived based on the Enskog--Vlasov kinetic equation as an example of practical importance.