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Related papers: Instabilities in a self-gravitating granular gas

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We have obtained the Vlasov equation and Boltzmann kinetic equation using Poisson bracket (classical Hamilton equation) and Rindler Hamiltonian. Further, we treat the whole Universe as a statistical system with galaxies as the point…

General Physics · Physics 2017-01-17 Soma Mitra , Somenath Chakrabarty

Similar to the treatment of dense gases, fluid-dynamic equations for the dynamics of congested vehicular traffic are derived from Enskog-like kinetic equations. These contain additional terms due to the anisotropic vehicle interactions. The…

Statistical Mechanics · Physics 2009-10-31 Dirk Helbing

The kinetic theory description of a low density gas of hard spheres or disks, confined between two parallel plates separated a distance smaller than twice the diameter of the particles, is addressed starting from the Liouville equation of…

Statistical Mechanics · Physics 2024-09-06 J. Javier Brey , M. I. García de Soria , P. Maynar

A polyatomic ideal gas with weak interaction between the translational and internal modes is considered. For the purpose of describing the behavior of such a gas, a Boltzmann equation is proposed in the form that the collision integral is a…

Analysis of PDEs · Mathematics 2026-03-31 Kazuo Aoki , Niclas Bernhoff

We develop a formulation of global thermodynamics for equilibrium systems under the influence of gravity. The free energy for simple fluids is extended to include a dependence on $(T, V, N, mgL)$, where $L$ represents the vertical system…

Statistical Mechanics · Physics 2025-06-26 Naoko Nakagawa , Shin-ichi Sasa , Takamichi Hirao , Tsuyoshi Shiina , Kyosuke Tachi , Akira Yoshida

The self-diffusion coefficient of a granular gas in the homogeneous cooling state is analyzed near the shearing instability. Using mode-coupling theory, it is shown that the coefficient diverges logarithmically as the instability is…

Statistical Mechanics · Physics 2015-07-02 J. Javier Brey , Maria J. Ruiz-Montero

The departure of a granular gas in the instable region of parameters from the initial homogeneous cooling state is studied. Results from Molecular Dynamics and from Direct Monte Carlo simulation of the Boltzmann equation are compared. It is…

Statistical Mechanics · Physics 2009-11-10 J. Javier Brey , M. J. Ruiz-Montero

The hydrodynamic instabilities of propagating interfaces in Hele-Shaw channels or porous media under the influence of an imposed flow and gravitational acceleration are investigated within the framework of Darcy's law. The stability…

Fluid Dynamics · Physics 2025-01-13 Joel Daou , Prabakaran Rajamanickam

We investigate the behavior of energy fluctuations in several models of granular gases maintained in a non-equilibrium steady state. In the case of a gas heated from a boundary, the inhomogeneities of the system play a predominant role.…

Statistical Mechanics · Physics 2007-05-23 P. Visco , A. Puglisi , A. Barrat , F. van Wijland , E. Trizac

In this paper we study a simple model consisting of a dilute fully ionized plasma in the presence of the gravitational and a constant magnetic field to analyze the propagation of hydromagnetic instabilities. In particular we show that the…

Astrophysics · Physics 2007-05-23 A. Sandoval-Villalbazo , L. S. Garcia-Colin , A. Arrieta

Many important properties of granular fluids can be represented by a system of hard spheres with inelastic collisions. Traditional methods of nonequilibrium statistical mechanics are effective for analysis and description of the inelastic…

Soft Condensed Matter · Physics 2009-11-07 James W. Dufty , J. Javier Brey , James Lutsko

A thermodynamically consistent particle-based model for fluid dynamics with continuous velocities and a non-ideal equation of state is presented. Excluded volume interactions are modeled by means of biased stochastic multiparticle…

Soft Condensed Matter · Physics 2009-11-11 Thomas Ihle , Erkan Tuzel , Daniel M. Kroll

The Lagrangian fluid description is employed to solve the initial value problem for one-dimensional, compressible fluid flows represented by the Euler-Poisson system. Exact nonlinear and time-dependent solutions are obtained, which exhibit…

Plasma Physics · Physics 2017-09-06 A. R. Karimov , H. Schamel

The kinetic theory of dilute granular gases having an inverse power law repulsive potential is studied. We derive the time evolution of the temperature and the transport coefficients from the Boltzmann equation. We also investigate the…

Soft Condensed Matter · Physics 2024-06-18 Satoshi Takada

A formal derivation of linear hydrodynamics for a granular fluid is given. The linear response to small spatial perturbations of the homogeneous reference state is studied in detail using methods of non-equilibrium statistical mechanics. A…

Statistical Mechanics · Physics 2007-05-23 James W. Dufty , Aparna Baskaran , J. Javier Brey

We review stability and instability results for self-gravitating matter distributions, where the matter model is a collisionless gas as described by the Vlasov equation. The focus is on the general relativistic situation, i.e., on steady…

General Relativity and Quantum Cosmology · Physics 2024-12-16 Gerhard Rein

The homogeneous steady state of a fluid of inelastic hard spheres immersed in a bath of elastic hard spheres kept at equilibrium is analyzed by means of the first Sonine approximation to the (spatially homogeneous) Enskog--Boltzmann…

Statistical Mechanics · Physics 2007-05-23 Andres Santos

We develop a general theory of buoyancy instabilities in the electron-ion plasma with the electron heat flux based not upon MHD equations, but using a multicomponent plasma approach in which the momentum equation is solved for each species.…

Astrophysics of Galaxies · Physics 2015-05-20 Anatoly K. Nekrasov , Mohsen Shadmehri

We investigate in this article the long-time behaviour of the solutions to the energy-dependant, spatially-homogeneous, inelastic Boltzmann equation for hard spheres. This model describes a diluted gas composed of hard spheres under…

Analysis of PDEs · Mathematics 2012-07-18 Thomas Rey

A kinetic model for granular mixtures is considered to study three different non-equilibrium situations. The model is based on the equivalence between a gas of elastic hard spheres subjected to a drag force proportional to the particle…

Soft Condensed Matter · Physics 2025-02-27 Pablo Avilés , David González Méndez , Vicente Garzó