Comment on "Current fluctuations in non-equilibrium diffusive systems: an additivity principle"

TL;DR

This paper clarifies that the additivity principle and scaling hypothesis in non-equilibrium diffusive systems naturally emerge from the saddle point analysis of a diffusive field theory, providing a theoretical foundation.

Contribution

It demonstrates that the additivity principle and scaling hypothesis are direct consequences of saddle point evaluation, offering a theoretical explanation for these concepts.

Findings

Additivity principle follows from saddle point analysis

Scaling hypothesis emerges naturally from the field theory

Provides a theoretical foundation for previous empirical postulates

Abstract

We point out that the "additivity principle" and "scaling hypothesis" postulated by Bodineau and Derrida in Phys. Rev. Lett 92, 180601 (2004), follow naturally from the saddle point evaluation of a diffusive field theory.