Non-equilibrium thermodynamics and stochasticity: a phenomenological look on Jarzynski’s equality

The theory of phenomenological non-equilibrium thermodynamics is extended by including stochastic processes in order to account for recently derived thermodynamical relations such as the Jarzynski’s equality. Four phenomenological axioms are postulated resulting in a phenomenological interpretation of Jarzynski’s equality. In particular, considering the class of Jarzynski processes Jarzynski’s equality follows from the axiom that the statistical average of the exponential work is protocol independent.