@article{b,
title = {Entropy for relaxation dynamics in granular media},
author = {Emauele Caglioti and Vittorio Loreto},
url = {http://prl.aps.org/abstract/PRL/v83/i21/p4333_1, http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=000083745600028&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=0c7ff228ccbaaa74236f48834a34396a},
year = {1999},
date = {1999-01-01},
journal = {PHYSICAL REVIEW LETTERS},
volume = {83},
pages = {4333--4336},
abstract = {We investigate the role of entropic concepts for the relaxation dynamics in granular systems. In these systems the existence of a geometrical frustration induces a drastic modification of the allowed phase space, which in its turn induces a dynamic behavior characterized by hierarchical relaxation phenomena with several time scales associated. In particular we show how, in the framework of a mean-field model introduced for the compaction phenomenon, there exists a free-energy-like functional which decreases along the trajectories of the dynamics and which allows to account for the asymptotic behavior: e.g. density profile, segregation phenomena. Also we are able to perform the continuous limit of the above mentioned model which turns out to be a diffusive limit. In this framework one can single out two separate physical ingredients: the free-energy-like functional that defines the phase-space and the asymptotic states and a diffusion coefficient $D(rho)$ accounting for the velocity of approach to the asymptotic stationary states.},
keywords = {caglioti, granular_media, loreto},
pubstate = {published},
tppubtype = {article}
}
We investigate the role of entropic concepts for the relaxation dynamics in granular systems. In these systems the existence of a geometrical frustration induces a drastic modification of the allowed phase space, which in its turn induces a dynamic behavior characterized by hierarchical relaxation phenomena with several time scales associated. In particular we show how, in the framework of a mean-field model introduced for the compaction phenomenon, there exists a free-energy-like functional which decreases along the trajectories of the dynamics and which allows to account for the asymptotic behavior: e.g. density profile, segregation phenomena. Also we are able to perform the continuous limit of the above mentioned model which turns out to be a diffusive limit. In this framework one can single out two separate physical ingredients: the free-energy-like functional that defines the phase-space and the asymptotic states and a diffusion coefficient $D(rho)$ accounting for the velocity of approach to the asymptotic stationary states.
