Macroscopic proof of the Jarzynski-Wojcik fluctuation theorem for heat exchange

TL;DR

This paper provides a macroscopic proof of the Jarzynski-Wojcik fluctuation theorem for heat exchange, demonstrating its validity using thermodynamic quantities and detailed balance, under broad conditions.

Contribution

It offers a new macroscopic proof of the fluctuation theorem for heat exchange, emphasizing the role of detailed balance and broad applicability.

Findings

The fluctuation theorem holds under very general conditions.

Macroscopic thermodynamic quantities suffice for the proof.

Detailed balance is crucial for the theorem's validity.

Abstract

In a recent work, Jarzynski and Wojcik (2004 Phys. Rev. Lett. 92, 230602) have shown by using the properties of Hamiltonian dynamics and a statistical mechanical consideration that, through contact, heat exchange between two systems initially prepared at different temperatures obeys a fluctuation theorem. Here, another proof is presented, in which only macroscopic thermodynamic quantities are employed. The detailed balance condition is found to play an essential role. As a result, the theorem is found to hold under very general conditions.