Entropy production and the arrow of time

Abstract

Abstract. We present an exact relationship between the entropy production and the distinguishability of a process from its time-reverse, quantified by the relative entropy between forward and backward states. The relationship is shown to remain valid for a wide family of initial conditions, such as canonical, constrained canonical, multicanonical and grand canonical distributions, as well as both for classical and quantum systems. PACS numbers: 05.70.Ln, 05.40.-aEntropy production and the arrow of time. 2 1.