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arXiv · 0804.2329

Breakdown of fluctuation-dissipation relations in granular gases

J. J. Brey·M. I. Garcia de Soria·P. Maynar
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Abstract

A numerical molecular dynamics experiment measuring the two-time correlation function of the transversal velocity field in the homogeneous cooling state of a granular gas is reported. By measuring the decay rate and the amplitude of the correlations, the accuracy of the Landau-Langevin equation of fluctuating hydrodynamics is checked. The results indicate that although a Langevin approach can be valid, the fluctuation-dissipation relation must be modified, since the viscosity parameter appearing in it differs from the usual hydrodynamic shear viscosity.

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J. J. Brey, M. I. Garcia de Soria, P. Maynar. 2008-04-15. Breakdown of fluctuation-dissipation relations in granular gases. https://doi.org/10.1209/0295-5075/84/24002

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