Entropy production along a stochastic trajectory and an integral fluctuation theorem

Abstract

For stochastic nonequilibrium dynamics like a Langevin equation for a colloidal particle or a master equation for discrete states, entropy production along a single trajectory is studied. It involves both genuine particle entropy and entropy production in the surrounding medium. The integrated sum of both Δstot is shown to obey a fluctuation theorem exp [-Δstot] = 1 for arbitrary initial conditions and arbitrary time-dependent driving over a finite time interval. © 2005 The American Physical Society.