Paolo Visco

FLUCTUATION RELATION AND BOUNDARY TERMS

The fluctuation relation is expected to hold for the entropy flux distribution in systems with stochastic dynamics. In this talk, this relation is investigated for two models of single particle systems (a granular tracer particle in a non-equilibrium bath, and a Brownian particle between two thermostats), and turns out not to be systematically verified. This breakdown seems to arise from the presence of boundary terms, which, although apparently small, turn out to dominate the statistics of very rare events. This phenomenon points to the relevance of the initial (and final) conditions in the determination of large deviation functions.