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Related papers: Instabilities in a self-gravitating granular gas

200 papers

Previous experiments have revealed that shock waves driven through dissipative gases may become unstable, for example, in granular gases, and in molecular gases undergoing strong relaxation effects. The mechanisms controlling these…

Soft Condensed Matter · Physics 2015-02-03 Nick Sirmas , Matei I. Radulescu

We investigate the inelastic hard disk gas sheared by two parallel bumpy walls (Couette-flow). In our molecular dynamic simulations we found a sensitivity to the asymmetries of the initial condition of the particle places and velocities and…

Soft Condensed Matter · Physics 2009-10-31 M. Sasvari , J. Kertesz , D. E. Wolf

We obtain the first rigorous derivation of an incompressible Navier-Stokes-Fourier system with self-consistent and time-dependent forcing terms from the inelastic hard-spheres Boltzmann equation associated to the relevant case of…

Analysis of PDEs · Mathematics 2025-11-27 R. Alonso , B. Lods , I. Tristani

The well-known Jeans criterion describes the onset of instabilities in an infinite, homogeneous, self-gravitating medium supported by pressure. Most realistic astrophysical systems, however, are not isolated - instead they are under the…

Astrophysics of Galaxies · Physics 2015-06-16 Chanda J. Jog

The linearized Boltzmann equation is considered to describe small spatial perturbations of the homogeneous cooling state. The corresponding macroscopic balance equations for the density, temperature, and flow velocity are derived from it as…

Statistical Mechanics · Physics 2015-06-24 J. Javier Brey , James W. Dufty , M. J. Ruiz-Montero

We study fluidized granular gases in a stationary state determined by the balance between an external driving and the bulk dissipation. The two considered situations are inspired by recent experiments, where the gravity plays a major role…

Statistical Mechanics · Physics 2009-10-31 A. Baldassarri , U. Marini Bettolo Marconi , A. Puglisi , A. Vulpiani

The linear hydrodynamic stability of a model for confined quasi-two-dimensional granular gases is analyzed. The system exhibits homogeneous hydrodynamics, i.e. there are macroscopic evolution equations for homogeneous states. The stability…

Statistical Mechanics · Physics 2016-10-12 J. Javier Brey , V. Buzón , M. I. García de Soria , P. Maynar

We explore instabilities in binary superfluids with a nonvanishing relative superflow, particularly focusing on counterflow and coflow instabilities. We extend recent results on the thermodynamic origin of finite superflow instabilities in…

High Energy Physics - Theory · Physics 2026-01-08 Yuping An , Blaise Goutéraux , Li Li

The local balance equations for the density, momentum, and energy of a dilute gas of elastic or inelastic hard spheres, strongly confined between two parallel hard plates are obtained. The starting point is a Boltzmann-like kinetic…

Statistical Mechanics · Physics 2020-04-22 J. Javier Brey , P. Maynar , M. I. García de Soria

This paper is the fourth in a series exploring the physical consequences of the solidity of highly viscous liquids. It is argued that the two basic characteristics of a flow event (a jump between two energy minima in configuration space)…

Soft Condensed Matter · Physics 2007-05-23 Jeppe C. Dyre

I review the basic ``gravitational instability'' model for the growth of structure in the expanding Universe. This model requires the existence of small initial irregularities in the density of a largely uniform universe. These grow through…

Astrophysics · Physics 2007-05-23 Peter Coles

We formulate a perturbative approximation to gravitational instability, based on Lagrangian hydrodynamics in Newtonian cosmology. We take account of `pressure' effect of fluid, which is kinematically caused by velocity dispersion, to aim…

Astrophysics · Physics 2009-11-07 Masaaki Morita , Takayuki Tatekawa

We present event-driven simulations of a granular gas of inelastic hard disks with incomplete normal restitution in two dimensions between vibrating walls (without gravity). We measure hydrodynamic quantities such as the stress tensor,…

Statistical Mechanics · Physics 2007-05-23 Olaf Herbst , Peter Müller , Matthias Otto , Annette Zippelius

We study steady-state properties of inelastic gases in two-dimensions in the presence of an energy source. We generalize previous hydrodynamic treatments to situations where high and low density regions coexist. The theoretical predictions…

Condensed Matter · Physics 2009-10-28 E. L. Grossman , T. Zhou , E. Ben-Naim

In this paper, we study the dynamical irregularity of the locally anisotropic spherical fluids in the context of Einstein-Gauss-Bonnet theory. We aim to describe the causes of energy-density irregularity of self-gravitating fluids and…

General Relativity and Quantum Cosmology · Physics 2025-09-03 Z. Yousaf , Kazuharu Bamba , Mansoor Alshehri , A. Farhat

Conditions for the stability under linear perturbations around the homogeneous cooling state are studied for dilute granular gases of inelastic and rough hard disks or spheres with constant coefficients of normal ($\alpha$) and tangential…

Soft Condensed Matter · Physics 2021-09-16 Alberto Megías , Andrés Santos

We consider the single-particle velocity distribution of a one-dimensional fluid of inelastic particles. Both the freely evolving (cooling) system and the non-equilibrium stationary state obtained in the presence of random forcing are…

Statistical Mechanics · Physics 2009-11-07 A. Barrat , T. Biben , Z. Racz , E. Trizac , F. van Wijland

We consider a two-dimensional, incompressible, inviscid fluid with variable density, subject to the action of gravity. Assuming a stable equilibrium density profile, we adopt the so-called Boussinesq approximation, which neglects density…

Analysis of PDEs · Mathematics 2025-07-15 R. Bianchini , A. Maspero , S. Pasquali

A study was made of the instability that arises when acoustic and gravity waves propagate in an inhomogeneous medium which is characterized by oscillatory approach of the reaction coordinates to the steady state. It is shown that loss of…

Chemical Physics · Physics 2020-11-12 N. N. Myagkov

An overview of recent results pertaining to the hydrodynamic description (both Newtonian and non-Newtonian) of granular gases described by the Boltzmann equation for inelastic Maxwell models is presented. The use of this mathematical model…

Soft Condensed Matter · Physics 2011-08-30 V. Garzó , A. Santos