English
Related papers

Related papers: Kinetic equation model for self-gravitating system…

200 papers

In this paper we study the kinetic theory of many-particle astrophysical systems imposing axial symmetry and extending our previous analysis in Phys. Rev. D 83, 123007 (2011). Starting from a Newtonian model describing a collisionless…

General Relativity and Quantum Cosmology · Physics 2012-08-23 J. Ramos-Caro , C. A. Agón , J. F. Pedraza

We introduce and discuss an effective model of a self-gravitating system whose equilibrium thermodynamics can be solved in both the microcanonical and the canonical ensemble, up to a maximization with respect to a single variable. Such a…

Statistical Mechanics · Physics 2010-05-21 Lapo Casetti , Cesare Nardini

We study long-range interacting systems perturbed by external stochastic forces. Unlike the case of short-range systems, where stochastic forces usually act locally on each particle, here we consider perturbations by external stochastic…

Statistical Mechanics · Physics 2013-12-04 Cesare Nardini , Shamik Gupta , Stefano Ruffo , Thierry Dauxois , Freddy Bouchet

The behavior of dynamical system interacting with non-equilibrium medium is investigated. Formally exact kinetic equations are derived for the statistical operator of the dynamical system and the macroscopic parameters of the medium. In the…

Statistical Mechanics · Physics 2016-12-30 Mikheil Zviadadze , Alexander kvirikadze

A model of self-driven particles similar to the Vicsek model [Phys. Rev. Lett. 75 (1995) 1226] but with metric-free interactions is studied by means of a novel Enskog-type kinetic theory. In this model, N particles of constant speed v0 try…

Statistical Mechanics · Physics 2012-08-21 Yen-Liang Chou , Rylan Wolfe , Thomas Ihle

Bhatnagar-Gross-Krook (BGK) equation is a relaxation model of the Boltzmann equation which is widely used in place of the Boltzmann equation for the simulation of various kinetic flow problems. In this work, we study the asymptotic…

Analysis of PDEs · Mathematics 2023-01-26 Gi-Chan Bae , Gyounghun Ko , Donghyun Lee , Seok-Bae Yun

We study the equilibria of a self-gravitating scalar field in the region outside a reflecting barrier. By introducing a potential difference between the barrier and infinity, we create a kink which cannot decay to a zero energy state. In…

General Relativity and Quantum Cosmology · Physics 2007-05-23 W. Barreto , R. Gomez , L. Lehner , J. Winicour

The Boltzmann equation describes the detailed microscopic behaviour of a dilute gas, and represents the basis of the kinetic theory of gases. In order to reduce the difficulties in solving the Boltzmann equation, simple expressions of a…

Mathematical Physics · Physics 2018-12-06 Armando Majorana

In this paper we study the kinetic theory of many-particle astrophysical systems and we present a consistent version of the collisionless Boltzmann equation in the 1PN approximation. We argue that the equation presented by Rezania and…

General Relativity and Quantum Cosmology · Physics 2011-07-04 C. A. Agón , J. F. Pedraza , J. Ramos-Caro

A kinetic equation for the collisional evolution of stable, bound, self gravitating and slowly relaxing systems is established, which is valid when the number of constituents is very large. It accounts for the detailed dynamics and self…

Astrophysics of Galaxies · Physics 2010-05-04 Jean Heyvaerts

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…

General Relativity and Quantum Cosmology · Physics 2026-04-13 Philip Semrén , Michael Bradley , João M. S. Oliveira , M. Piedade Machado Ramos

We use kinetic theory in order to study the role of quantum fluctuations in the isotropization of the pressure tensor in a system subject to fast longitudinal expansion, such as the matter produced in the early stages of a heavy ion…

High Energy Physics - Phenomenology · Physics 2016-04-20 Francois Gelis

The linear equations of motion of a uniformly rotating, elastic and self-gravitating earth model are analyzed under minimal regularity assumptions. We present existence and uniqueness results for the system, energy estimates, convergence of…

Mathematical Physics · Physics 2017-04-12 Maarten V. de Hoop , Sean Holman , Ha Pham

The Bhatnagar-Gross-Krook (BGK) single-relaxation-time collision model for the Boltzmann equation serves as the foundation of the lattice BGK (LBGK) method developed in recent years. The description of the collision as a uniform relaxation…

Numerical Analysis · Mathematics 2021-10-04 Xiaowen Shan , Yangyang Shi , Xuhui Li

Modified gravity theories can be used for the description of homogeneous and isotropic cosmological models through the corresponding field equations. These can be cast into systems of autonomous differential equations because of their sole…

General Relativity and Quantum Cosmology · Physics 2024-04-08 Christian G. Boehmer , Erik Jensko , Ruth Lazkoz

In $f(T)$ gravity, the theory modifies the gravitational action by introducing a function of the torsion scalar $T$. This approach allows for a different treatment of gravity than general relativity, particularly in cosmological contexts.…

General Relativity and Quantum Cosmology · Physics 2024-10-08 S. Davood Sadatian , S. Mohamad Reza Hosseini

We complete the existing literature on the kinetic theory of systems with long-range interactions. Starting from the BBGKY hierarchy, or using projection operator technics or a quasilinear theory, a general kinetic equation can be derived…

Statistical Mechanics · Physics 2015-05-18 Pierre-Henri Chavanis

The theoretical understanding of pattern formation in active systems remains a central problem of interest. Heterogeneous flocks made up of multiple species can exhibit a remarkable diversity of collective states that cannot be obtained…

Statistical Mechanics · Physics 2025-12-23 Eloise Lardet , Letian Chen , Thibault Bertrand

The main purpose of this article is to provide a guide to theorems on global properties of solutions to the Einstein--Vlasov system. This system couples Einstein's equations to a kinetic matter model. Kinetic theory has been an important…

General Relativity and Quantum Cosmology · Physics 2015-05-28 Håkan Andréasson

In this thesis, we investigate the emergence of kinetic processes in finite quantum systems. We first generalize the Redfield theory to describe the dynamics of a small quantum system weakly interacting with an environment of finite heat…

Statistical Mechanics · Physics 2009-09-29 Massimiliano Esposito
‹ Prev 1 2 3 10 Next ›