Granular Brownian motion
Abstract
We study the stochastic motion of an intruder in a dilute driven granular gas. All particles are coupled to a thermostat, representing the external energy source, which is the sum of random forces and a viscous drag. The dynamics of the intruder, in the large mass limit, is well described by a linear Langevin equation, combining the effects of the external bath and of the "granular bath". The drag and diffusion coefficients are calculated under few assumptions, whose validity is well verified in numerical simulations. We also discuss the non-equilibrium properties of the intruder dynamics, as well as the corrections due to finite packing fraction or finite intruder mass.
Cite
@article{arxiv.1003.4462,
title = {Granular Brownian motion},
author = {Alessandro Sarracino and Dario Villamaina and Giulio Costantini and Andrea Puglisi},
journal= {arXiv preprint arXiv:1003.4462},
year = {2010}
}
Comments
19 pages, 4 figures, in press on Journal of Statistical Mechanics: Theory and Experiments