Entropy production fluctuations encode collective behavior in active matter

TL;DR

This paper establishes a lower bound on entropy production fluctuations in active matter, linking collective behavior and phase transitions, and proposes control strategies to manipulate system phases.

Contribution

It introduces a general bound on entropy production distributions in active matter and connects fluctuations to phase transitions, providing control methods for system manipulation.

Findings

Bound is tight with small, short-ranged correlations

Long-range correlations lead to enhanced fluctuations near phase transitions

Optimal control forces can tune system between phases

Abstract

We derive a general lower bound on distributions of entropy production in interacting active matter systems. The bound is tight in the limit that interparticle correlations are small and short-ranged, which we explore in four canonical active matter models. In all models studied, the bound is weak where collective fluctuations result in long-ranged correlations, which subsequently links the locations of phase transitions to enhanced entropy production fluctuations. We develop a theory for the onset of enhanced fluctuations and relate it to specific phase transitions in active Brownian particles. We also derive optimal control forces that realize the dynamics necessary to tune dissipation and manipulate the system between phases. In so doing, we uncover a general relationship between entropy production and pattern formation in active matter, as well as ways of controlling it.