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arXiv · 1007.0364

Irreversible dynamics of a massive intruder in dense granular fluids

Alessandro Sarracino·Dario Villamaina·Giacomo Gradenigo·Andrea Puglisi
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Abstract

A Generalized Langevin Equation with exponential memory is proposed for the dynamics of a massive intruder in a dense granular fluid. The model reproduces numerical correlation and response functions, violating the equilibrium Fluctuation Dissipation relations. The source of memory is identified in the coupling of the tracer velocity $V$ with a spontaneous local velocity field $U$ in the surrounding fluid. Such identification allows us to measure the intruder's fluctuating entropy production as a function of $V$ and $U$, obtaining a neat verification of the Fluctuation Relation.

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Alessandro Sarracino, Dario Villamaina, Giacomo Gradenigo, Andrea Puglisi. 2010-10-19. Irreversible dynamics of a massive intruder in dense granular fluids. https://doi.org/10.1209/0295-5075%2F92%2F34001

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