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We present the derivation of a novel third-order hydrodynamic evolution equation for shear stress tensor from kinetic theory. Boltzmann equation with relaxation time approximation for the collision term is solved iteratively using…

核理论 · 物理学 2013-09-02 Amaresh Jaiswal

In the present paper, we concern the hydrodynamic limit of Boltzmann equation with specular reflection boundary condition in a two-dimensional disk to the compressible Euler equations. Due to the non-zero curvature and non-zero tangential…

偏微分方程分析 · 数学 2025-04-22 Feimin Huang , Jing Ouyang , Yong Wang

We present an exact solution of the relativistic Boltzmann equation for a system undergoing boost-invariant longitudinal and azimuthally symmetric transverse flow ("Gubser flow"). The resulting exact non-equilibrium dynamics is compared to…

高能物理 - 唯象学 · 物理学 2014-11-17 Gabriel S. Denicol , Ulrich W. Heinz , Mauricio Martinez , Jorge Noronha , Michael Strickland

In the Hermite-expansion-based multiple-relaxation-time lattice Boltzmann (LB) model [Shan & Chen, Int. J. Mod. Phys. C, 18, 635, (2007)], a separate relaxation time is assigned to each of the tensorial moments of the collision term. Here…

计算物理 · 物理学 2021-05-05 Xuhui Li , Xiaowen Shan

A foundational question in relativistic fluid mechanics concerns the properties of the hydrodynamic gradient expansion at large orders. We establish the precise conditions under which this gradient expansion diverges for a broad class of…

高能物理 - 理论 · 物理学 2021-09-08 Michal P. Heller , Alexandre Serantes , Michał Spaliński , Viktor Svensson , Benjamin Withers

We obtain equations of motion for the boost-invariant expansion of a system of chiral particles. Our analysis is based on the Boltzmann equation for left- and right-handed massless particles in the relaxation time approximation. We assume…

高能物理 - 唯象学 · 物理学 2024-02-15 Nora Weickgenannt , Jean-Paul Blaizot

The Goldstein-Taylor equations can be thought of as a simplified version of a BGK system, where the velocity variable is constricted to a discrete set of values. It is intimately related to turbulent fluid motion and the telegrapher's…

偏微分方程分析 · 数学 2021-03-17 Anton Arnold , Amit Einav , Beatrice Signorello , Tobias Wöhrer

Consider 3D Boltzmann equation in convex domains with diffusive-reflection boundary condition. We study the hydrodynamic limits as the Knudsen number and Strouhal number $\epsilon\rightarrow 0^+$. Using the Hilbert expansion, we rigorously…

偏微分方程分析 · 数学 2020-10-02 Lei Wu , Zhimeng Ouyang

In this contribution, a new class of lattice Boltzmann schemes is introduced and studied. These schemes are presented in a framework that generalizes the multiple relaxation times method of d'Humi\`eres. They extend also the Geier's…

数值分析 · 数学 2015-01-27 François Dubois , Tony Fevrier , Benjamin Graille

The hydrodynamic limit for the Boltzmann equation is studied in the case when the limit system, that is, the system of Euler equations contains contact discontinuities. When suitable initial data is chosen to avoid the initial layer, we…

偏微分方程分析 · 数学 2015-05-13 Feimin Huang , Yi Wang , Tong Yang

This paper proposes a thorough theoretical analysis of Stochastic Gradient Descent (SGD) with non-increasing step sizes. First, we show that the recursion defining SGD can be provably approximated by solutions of a time inhomogeneous…

最优化与控制 · 数学 2021-02-02 Xavier Fontaine , Valentin De Bortoli , Alain Durmus

Here we derive the relativistic resistive dissipative second-order magnetohydrodynamic evolution equations using the Boltzmann equation, thus extending our work from the previous paper…

核理论 · 物理学 2021-09-27 Ankit Kumar Panda , Ashutosh Dash , Rajesh Biswas , Victor Roy

This paper addresses a new class of generalized Bolza problems governed by nonconvex integro-differential inclusions with endpoint constraints on trajectories, where the integral terms are given in the general (with time-dependent…

最优化与控制 · 数学 2024-10-07 Abderrahim Bouach , Tahar Haddad , Boris S. Mordukhovich

Gradient algorithms are classical in adaptive control and parameter estimation. For instantaneous quadratic cost functions they lead to a linear time-varying dynamic system that converges exponentially under persistence of excitation…

最优化与控制 · 数学 2020-10-06 Juan G. Rueda-Escobedo , Jaime A. Moreno

We consider a class of nonlinear Boltzmann equations describing return to thermal equilibrium in a gas of colliding particles suspended in a thermal medium. We study solutions in the space $L^{1}(\mathbb{R}^{3}\times \mathbb{T}^3).$ Special…

偏微分方程分析 · 数学 2016-12-28 Juerg Froehlich , Zhou Gang

I demonstrate that the concept of a non-equilibrium attractor can be extended beyond the lowest-order moments typically considered in hydrodynamic treatments. Using a previously obtained exact solution to the relaxation-time approximation…

核理论 · 物理学 2022-01-12 Michael Strickland

We use a set of simple angular moments to solve the Boltzmann equation in the relaxation time approximation for a boost invariant longitudinally expanding gluonic plasma. The transition from the free streaming regime at early time to the…

核理论 · 物理学 2020-01-08 Jean-Paul Blaizot , Li Yan

A type of discrete Boltzmann model for simulating shallow water flows is derived by using the Hermite expansion approach. Through analytical analysis, we study the impact of truncating distribution function and discretizing particle…

流体动力学 · 物理学 2018-07-16 Jianping Meng , Xiao-Jun Gu , David R Emerson , Yong Peng , Jianmin Zhang

A simplified relativistic kinetic theory for gases with internal degrees of freedom, based on a BGK-type collision term, is considered. First the Boltzmann equation is rewritten in tetrad form and then thermal coefficients are determined to…

广义相对论与量子宇宙学 · 物理学 2026-04-13 Philip Semrén , Michael Bradley , João M. S. Oliveira , M. Piedade Machado Ramos

One-dimensional self-gravitating systems admit genuine thermodynamical equilibria. For systems with strictly monotonic orbital frequency profile, the Landau and Balescu-Lenard theories predict a relaxation time scaling linearly with the…

星系天体物理 · 物理学 2026-03-13 Kerwann Tep , Jean-Baptiste Fouvry , Christophe Pichon