title: Inflow rate, a time-symmetric observable obeying fluctuation relations.
abstract: While entropy changes are the usual subject of fluctuation theorems, we seek fluctuation relations involving time-symmetric quantities, namely observables that do not change sign if the trajectories are observed backward in time. We find detailed and integral fluctuation relations for the (time-integrated) difference between entrance rate and escape rate in mesoscopic jump systems. Such inflow rate, which is even under time reversal, represents the discrete-state equivalent of the phase-space contraction rate. Indeed, it becomes minus the divergence of forces in the continuum limit to overdamped diffusion. This establishes a formal connection between reversible deterministic systems and irreversible stochastic ones, confirming that fluctuation theorems are largely independent of the details of the underling dynamics.
authors.affiliation: Department of Physics and Astronomy, University of Padova, Via Marzolo 8, I-35131 Padova, Italy.|INFN, Sezione di Padova, Via Marzolo 8, I-35131 Padova, Italy.
authors.forename: Marco
authors.initials: M
authors.lastname: Baiesi
authors.affiliation: Institut für Theoretische Physik, Universität Leipzig, Postfach 100 920, D-04009 Leipzig, Germany.
authors.forename: Gianmaria
authors.initials: G
authors.lastname: Falasco