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We present a new method for imposing a realistic equation of state in anisotropic hydrodynamics. The method relies on the introduction of a single finite-temperature quasiparticle mass which is fit to lattice data. By taking moments of the…

High Energy Physics - Phenomenology · Physics 2015-11-30 Mubarak Alqahtani , Mohammad Nopoush , Michael Strickland

We consider the kinetic transport equation that arise in the Boltzmann-Grad limit of the two-dimensional periodic Lorentz Gas. This equation has been obtained by extending the phase space of positions and velocities through the introduction…

Mathematical Physics · Physics 2026-03-17 Francesca Pieroni

We show the convergence of the zero relaxation limit in systems of $2 \times 2$ hyperbolic conservation laws with stochastic initial data. Precisely, solutions converge to a solution of the local equilibrium approximation as the relaxation…

Analysis of PDEs · Mathematics 2018-11-01 James M. Scott , M. Paul Laiu , Cory D. Hauck

We present a rigorous analysis of the Landau-Zener linear-in-time term crossing problem for quadratic-nonlinear systems relevant to the coherent association of ultracold atoms in degenerate quantum gases. Our treatment is based on an exact…

Quantum Gases · Physics 2009-11-01 A. Ishkhanyan , B. Joulakian , K. -A. Suominen

Slow (logarithmic) relaxation from a highly excited state is studied in a Hamiltonian system with many degrees of freedom. The relaxation time is shown to increase as the exponential of the square root of the energy of excitation, in…

Condensed Matter · Physics 2007-05-23 Naoko Nakagawa , Kunihiko Kaneko

The relaxation time approximation (RTA) of the kinetic Boltzmann equation is likely the simplest window into the microscopic properties of collective real-time transport. Within this framework, we analytically compute all retarded two-point…

High Energy Physics - Theory · Physics 2024-07-23 Matej Bajec , Sašo Grozdanov , Alexander Soloviev

This paper presents a toy model of a charged relativistic classical gas in flat spacetime of an arbitrary number of dimensions equipped with some ``pair production'' mechanism. Working with the microcanonical ensemble, the charge is taken…

Statistical Mechanics · Physics 2023-04-04 C. P. Felix , E. S. Moreira

We present and discuss a variance-reduced stochastic particle method for simulating the relaxation-time model of the Boltzmann transport equation. The present paper focuses on the dilute gas case, although the method is expected to directly…

Computational Physics · Physics 2009-05-15 Nicolas G. Hadjiconstantinou , Gregg A. Radtke , Lowell L. Baker

We investigate numerically a recent BGK-type model for a multi-component mixture of monatomic gases, undergoing a reversible bimolecular chemical reaction. The model replaces each collisional term of the Boltzmann equation with a relaxation…

Statistical Mechanics · Physics 2026-02-23 Giorgio Martalò , Ana Jacinta Soares , Romina Travaglini

The non-equilibrium contributions to the post-Newtonian hydrodynamic equations are determined from a relaxation-time model of the post-Newtonian Boltzmann equation. The Chapman-Enskog method is used to calculate the non-equilibrium…

General Relativity and Quantum Cosmology · Physics 2023-04-05 Gilberto M. Kremer

The thermal relaxation of a dense gas described by the modified Enskog equation is studied for a closed system in contact with a heat bath. As in the case of the Boltzmann equation, the Helmholtz free energy $\mathcal{F}$ that decreases…

Mathematical Physics · Physics 2023-05-22 Shigeru Takata

We present a unified account of damping of low-lying collective modes and of relaxation of temperature anisotropies in a trapped Bose gas in the collisionless regime. By means of variational techniques, we show that the relaxation times for…

Condensed Matter · Physics 2009-10-31 G. M. Kavoulakis , C. J. Pethick , H. Smith

Nonequilibrium thermodynamics of a general second-order stochastic system is investigated. We prove that at steady state, under inversion of velocities, the condition of time-reversibility over the phase space is equivalent to the…

Statistical Mechanics · Physics 2015-10-28 Hao Ge

We consider an application of the tetrad formalism introduced by Cardall et al. [Phys. Rev. D 88 (2013) 023011] to the problem of a rigidly rotating relativistic gas in thermal equilibrium and discuss the possible applications of this…

High Energy Astrophysical Phenomena · Physics 2016-04-11 Victor E. Ambrus , Robert Blaga

We derive the equations of motion of relativistic magnetohydrodynamics from the Boltzmann equation using the method of moments. We consider a locally electrically neutral system composed of two particle species with opposite charges, with…

High Energy Astrophysical Phenomena · Physics 2026-02-25 Khwahish Kushwah , Gabriel Silveria Denicol

We derive a linearly causal and stable third-order relativistic fluid-dynamical theory from the Boltzmann equation using the method of moments. For this purpose, we demonstrate that such theory must include novel degrees of freedom,…

Nuclear Theory · Physics 2023-02-21 Caio V. P. de Brito , Gabriel S. Denicol

In the Bona-Masso formulation, Einstein equations are written as a set of flux conservative first order hyperbolic equations that resemble fluid dynamics equations. Based on this formulation, we construct a lattice Boltzmann model for…

Computational Physics · Physics 2016-02-17 E. Ilseven , M. Mendoza

We prove the so-called generalized Haff's law yielding the optimal algebraic cooling rate of the temperature of a granular gas described by the homogeneous Boltzmann equation for inelastic interactions with non constant restitution…

Analysis of PDEs · Mathematics 2010-07-28 Ricardo J. Alonso , Bertrand Lods

In this work we study a r-species mixture of gases within the relativistic kinetic theory point of view. We use the relativistic covariant full Boltzmann equation and we incorporate the Schwarzschild metric. The method of solution of the…

Statistical Mechanics · Physics 2015-09-10 Valdemar Moratto , Gilberto M. Kremer

A fundamental question in many-body physics is how closed quantum systems reach equilibrium. We address this question experimentally and theoretically in an ultracold large-spin Fermi gas where we find a complex interplay between internal…

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