Violation of the Einstein relation in Granular Fluids: the role of correlations
Statistical Mechanics
2009-11-13 v1 Soft Condensed Matter
Abstract
We study the linear response in different models of driven granular gases. In some situations, even if the the velocity statistics can be strongly non-Gaussian, we do not observe appreciable violations of the Einstein formula for diffusion versus mobility. The situation changes when strong correlations between velocities and density are present: in this case, although a form of fluctuation-dissipation relation holds, the differential velocity response of a particle and its velocity self-correlation are no more proportional. This happens at high densities and strong inelasticities, but still in the fluid-like (and ergodic) regime.
Keywords
Cite
@article{arxiv.0705.2688,
title = {Violation of the Einstein relation in Granular Fluids: the role of correlations},
author = {A. Puglisi and A. Baldassarri and A. Vulpiani},
journal= {arXiv preprint arXiv:0705.2688},
year = {2009}
}
Comments
18 pages, 6 figures, submitted for publication