Relativistic Fluctuation Theorems
  Fluctuation Theorems are statements about the entropy of systems far from thermal equilibrium. In this Letter relativistic Fluctuation Theorems for Brownian motion are presented and proven. Though there is a known discretization dilemma leading to a certain class of Brownian processes, the Fluctuation Theorems are shown to cover the entire class, and to determine the physical process within this class. In the general-relativistic case the heat responsible for entropy production is the exchanged 4-momentum projected on the local time axis of the heat bath. 
Axel Fingerle