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Related papers: Self-diffusion in granular gases

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Exact analytic solutions of a nonlinear boson diffusion equation with suitable initial conditions that account for evaporative cooling of ultracold atoms, plus boundary conditions at the singularity $\epsilon=\mu<0$ are presented, and used…

Quantum Gases · Physics 2020-04-02 Georg Wolschin

We develop a theoretical formalism for time-dependent radiative heat flux from one object to another in the case where the former starts radiating at a certain time. The time dependence is demonstrated for the heat flux between two isolated…

Quantum Physics · Physics 2025-02-11 Kiryl Asheichyk

We investigate the diffusive scaling of the Lorentz gas in the presence of an external force of mean-field type. In the weak coupling regime and for diffusive time scales, the test particle's law converges to the probability density…

Mathematical Physics · Physics 2024-11-07 Dominik Nowak

A polydisperse granular gas made of inelastic and rough hard disks is considered. Focus is laid on the kinetic-theory derivation of the partial energy production rates and the total cooling rate as functions of the partial densities and…

Soft Condensed Matter · Physics 2018-07-18 Andrés Santos

This paper presents a molecular dynamics simulation of an inelastic gas, where collisions between molecules are characterized by a coefficient of restitution less than unity. The simulation employs an event-driven algorithm to efficiently…

Computational Physics · Physics 2025-02-03 Rameez Farooq Shah , Shikha Kumari , Syed Rashid Ahmad

We introduce a model of self-propelled particles carrying out a Brownian motion with a diffusion coefficient which depends on the local density of particles within a certain finite radius. Numerical simulations show that in a range of…

Statistical Mechanics · Physics 2009-11-11 Cristobal Lopez

In this paper, the structural property of complex plasma and self-diffusion coefficient of dust particles in presence of such wake potential have been investigated using Langevin dynamics simulation in the subsonic regime of ion flow. The…

Plasma Physics · Physics 2017-02-22 Mahmuda Begum , Nilakshi Das

We study a two-dimensional granular system where external driving force is applied to each particle in the system in such a way that the system is driven into a steady state by balancing the energy input and the dissipation due to inelastic…

Statistical Mechanics · Physics 2009-10-30 Gongwen Peng , Takao Ohta

In a freely cooling granular material fluctuations in density and temperature cause position dependent energy loss. Due to strong local dissipation, pressure and energy drop rapidly and material moves from `hot' to `cold' regions, leading…

Statistical Mechanics · Physics 2007-05-23 Stefan Luding

We investigate the effect of fragmentation on the homogeneous free cooling of inelastic hard spheres, using Boltzmann kinetic theory and Direct Monte Carlo simulations. We analyze in detail a model where dissipative collisions may…

Statistical Mechanics · Physics 2015-06-24 Ignacio Pagonabarraga , Emmanuel Trizac

The velocity distribution of a granular gas is analyzed in terms of the Sonine polynomials expansion. We derive an analytical expression for the third Sonine coefficient a_3. In contrast to frequently used assumptions this coefficient is of…

Statistical Mechanics · Physics 2009-11-11 Nikolai V. Brilliantov , Thorsten Poeschel

The homogeneous state of a granular flow of smooth inelastic hard spheres or disks described by the Enskog-Boltzmann kinetic equation is analyzed. The granular gas is fluidized by the presence of a random force and a drag force. The…

Statistical Mechanics · Physics 2015-06-16 Moisés G. Chamorro , Francisco Vega Reyes , Vicente Garzó

We investigate the speed of approach to Maxwellian equilibrium for a collisionless gas enclosed in a vessel whose wall are kept at a uniform, constant temperature, assuming diffuse reflection of gas molecules on the vessel wall. We…

Analysis of PDEs · Mathematics 2012-07-26 Kazuo Aoki , François Golse

Free cooling of a gas of inelastically colliding hard spheres represents a central paradigm of kinetic theory of granular gases. At zero gravity the temperature of a freely cooling homogeneous granular gas follows a power law in time. How…

Soft Condensed Matter · Physics 2009-11-11 Dmitri Volfson , Baruch Meerson , Lev S. Tsimring

Temporal analyses of the prompt gamma-ray and X-ray light curves of gamma-ray bursts reveal a tendency for the burst pulse time scales to increase with decreasing energy. For an ensemble of BATSE bursts, Fenimore et al. (1995) show that the…

Astrophysics · Physics 2009-10-30 James Chiang

We investigate single-particle diffusion in a two-state Langevin model where the friction coefficient randomly switches between low-friction (liquid-like) and high-friction (glassy-like) states. The dynamics are governed by the ratio…

Chemical Physics · Physics 2025-12-03 Fivos Perakis , Takeshi Kawasaki , Shinji Saito

We discuss the nature of the velocity dispersion vs. size relation for molecular clouds. In particular, we add to previous observational results showing that the velocity dispersions in molecular clouds and cores are not purely functions of…

The periodic Lorentz gas is a paradigmatic model to examine how macroscopic transport emerges from microscopic chaos. It consists of a triangular lattice of circular hard scatterers with a moving point particle. Recently this system became…

Statistical Mechanics · Physics 2019-05-30 S. Gil-Gallegos , R. Klages , J. Solanpää , E. Räsänen

We compute the mean square displacement (MSD) of intruders immersed in a freely cooling granular gas made up of smooth inelastic hard spheres. In general, intruders and particles of the granular gas are assumed to have different mechanical…

Soft Condensed Matter · Physics 2022-06-23 Enrique Abad , Santos Bravo Yuste , Vicente Garzó

We obtain self-similar solutions that describe the dynamics of a self-gravitating, rotating, viscous system. We use simplifying assumptions; but explicitly include viscosity and the cooling due to the dissipation of energy. By assuming that…

Astrophysics · Physics 2009-11-07 Mohsen Shadmehri , Jamshid Ghanbari