Entropy production in continuous phase space systems

TL;DR

This paper introduces a new method for calculating entropy production in classical underdamped nonequilibrium systems within continuous phase space, highlighting differences in differential entropy production definitions.

Contribution

It presents an alternative approach that does not require distinguishing between even and odd-parity variables, and discusses the non-uniqueness of differential entropy production.

Findings

The new method matches previous local entropy production results.

Differential entropy production along trajectories is not uniquely defined.

The approach simplifies calculations by avoiding parity distinctions.

Abstract

We propose an alternative method to compute the entropy production of a classical underdamped nonequilibrium system in a continuous phase space. This approach has the advantage that it is not necessary to distinguish between even and odd-parity variables. We show that the method leads to the same local entropy production as in previous studies while the differential entropy production along a stochastic trajectory turns out to be different. This demonstrates that the differential entropy production in continuous phase space systems is not uniquely defined.