The linear response in different models of driven granular gases is studied. In some situations, even if the the velocity statistics can be strongly non-Gaussian, appreciable violations of the Einstein formula for diffusion versus mobility cannot be observed. The situation changes when correlations between different degrees of freedom 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, strong inelasticities, or weak efficiency of the external driving, but still in the fluid-like (and ergodic) regime.
%0 Journal Article
%1 baldassarri:911
%A Baldassarri, A.
%A Puglisi, A.
%A Vulpiani, A.
%D 2008
%E Co, Albert
%E Leal, Gary L.
%E Colby, Ralph H.
%E Giacomin, A. Jeffrey
%I AIP
%J THE XV INTERNATIONAL CONGRESS ON RHEOLOGY: The Society of Rheology 80th Annual Meeting
%K 2008 california conference fdt granular monterey myown physics proceeding
%N 1
%P 911-913
%R 10.1063/1.2964891
%T Fluctuations and Response in Granular Gases: Validity and Failure of Einstein Relation.
%U http://link.aip.org/link/?APC/1027/911/1
%V 1027
%X The linear response in different models of driven granular gases is studied. In some situations, even if the the velocity statistics can be strongly non-Gaussian, appreciable violations of the Einstein formula for diffusion versus mobility cannot be observed. The situation changes when correlations between different degrees of freedom 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, strong inelasticities, or weak efficiency of the external driving, but still in the fluid-like (and ergodic) regime.
@article{baldassarri:911,
abstract = {The linear response in different models of driven granular gases is studied. In some situations, even if the the velocity statistics can be strongly non-Gaussian, appreciable violations of the Einstein formula for diffusion versus mobility cannot be observed. The situation changes when correlations between different degrees of freedom 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, strong inelasticities, or weak efficiency of the external driving, but still in the fluid-like (and ergodic) regime.},
added-at = {2009-03-16T12:27:43.000+0100},
author = {Baldassarri, A. and Puglisi, A. and Vulpiani, A.},
biburl = {https://www.bibsonomy.org/bibtex/259dbd7169ba211c5884aa65c6e897546/andreab},
doi = {10.1063/1.2964891},
editor = {Co, Albert and Leal, Gary L. and Colby, Ralph H. and Giacomin, A. Jeffrey},
interhash = {4abe34759a4ffe544b9ea8b027cab99e},
intrahash = {59dbd7169ba211c5884aa65c6e897546},
journal = {THE XV INTERNATIONAL CONGRESS ON RHEOLOGY: The Society of Rheology 80th Annual Meeting},
keywords = {2008 california conference fdt granular monterey myown physics proceeding},
location = {Monterey (California)},
number = 1,
pages = {911-913},
publisher = {AIP},
timestamp = {2009-03-16T12:27:43.000+0100},
title = {Fluctuations and Response in Granular Gases: Validity and Failure of Einstein Relation.},
url = {http://link.aip.org/link/?APC/1027/911/1},
volume = 1027,
year = 2008
}