Statistics of the dissipated energy in driven diffusive systems

TL;DR

This paper explores the fluctuations of dissipated energy in driven non-equilibrium systems, extending macroscopic fluctuation theory to better understand energy dissipation in systems like granular media.

Contribution

It introduces a generalized macroscopic fluctuation theory for driven dissipative systems, addressing a gap in understanding energy dissipation in non-conservative systems.

Findings

Dissipated energy fluctuations can be characterized using a generalized MFT.

The approach provides insights into non-equilibrium energy dissipation.

Methodology applicable to granular media and similar systems.

Abstract

Understanding the physics of non-equilibrium systems remains as one of the major open questions in statistical physics. This problem can be partially handled by investigating macroscopic fluctuations of key magnitudes that characterise the non-equilibrium behaviour of the system of interest; their statistics, associated structures and microscopic origin. During the last years, some new general and powerful methods have appeared to delve into fluctuating behaviour that have drastically changed the way to address this problem in the realm of diffusive systems: macroscopic fluctuation theory (MFT) and a set of advanced computational techniques that make it possible to measure the probability of rare events. Notwithstanding, a satisfactory theory is still lacking in a particular case of intrinsically non-equilibrium systems, namely those in which energy is not conserved but dissipated continuously in the bulk of the system (e.g. granular media). In this work, we put forward the dissipated energy as a relevant quantity in this case and analyse in a pedagogical way its fluctuations, by making use of a suitable generalisation of macroscopic fluctuation theory to driven dissipative media.