Large Fluctuations in Driven Dissipative Media

TL;DR

This paper investigates the energy dissipation fluctuations in driven dissipative media using hydrodynamic fluctuation theory, revealing non-Gaussian behavior, universal scaling, and supporting the theory's applicability through simulations.

Contribution

It introduces a general model analyzing dissipation fluctuations, deriving the large deviation function, and confirming hydrodynamic fluctuation theory's validity in such systems.

Findings

Large deviation function is non-Gaussian and violates the fluctuation theorem.

Universal scaling forms are observed in weak and strong dissipation limits.

Simulations confirm the theoretical predictions and the applicability of hydrodynamic fluctuation theory.

Abstract

We analyze the fluctuations of the dissipated energy in a simple and general model where dissipation, diffusion and driving are the key ingredients. The large deviation function for the dissipation follows from hydrodynamic fluctuation theory and an additivity conjecture. This function is strongly non-Gaussian and has no negative branch, thus violating the fluctuation theorem as expected from the irreversibility of the dynamics. It exhibits simple, universal scaling forms in the weak- and strong-dissipation limits, with large fluctuations favoured in the former case but strongly suppressed in the latter. The typical path associated to a given dissipation fluctuation is also analyzed in detail. Our results, confirmed in extensive simulations, strongly support the validity of hydrodynamic fluctuation theory to describe fluctuating behavior in driven dissipative media.