Jarzynski Equality, Crooks Fluctuation Theorem and the Fluctuation Theorems of Heat for Arbitrary Initial States

TL;DR

This paper derives a new unified fluctuation theorem for stochastic thermodynamic systems that generalizes existing theorems like Jarzynski and Crooks, applicable to arbitrary initial states and processes with feedback control.

Contribution

It introduces a refined unified fluctuation theorem that encompasses various known theorems and extends their applicability to arbitrary initial distributions and feedback-controlled processes.

Findings

Reproduces Jarzynski equality and Crooks theorem as special cases.

Generalizes fluctuation theorems to arbitrary initial states.

Applicable to thermodynamic processes involving information exchange.

Abstract

By taking full advantage of the dynamic property imposed by the detailed balance condition, we derive a new refined unified fluctuation theorem (FT) for general stochastic thermodynamic systems. This FT involves the joint probability distribution functions of the final phase space point and a thermodynamic variable. Jarzynski equality, Crooks fluctuation theorem, and the FTs of heat as well as the trajectory entropy production can be regarded as special cases of this refined unified FT, and all of them are generalized to arbitrary initial distributions. We also find that the refined unified FT can easily reproduce the FTs for processes with the feedback control, due to its unconventional structure that separates the thermodynamic variable from the choices of initial distributions. Our result is heuristic for further understanding of the relations and distinctions between all kinds of FTs, and might be valuable for studying thermodynamic processes with information exchange.