Exact Hydrodynamic Description of Active Lattice Gases

TL;DR

This paper presents an exact hydrodynamic framework for active lattice gases, enabling precise modeling of collective behaviors like phase separation and collective motion in active matter systems.

Contribution

It introduces a class of lattice gas models with exactly derivable hydrodynamics, advancing understanding of active matter phenomena.

Findings

Derived coupled PDEs for density and polarization fields.

Quantitatively predicted phase separation and collective motion.

Validated models against macroscopic behaviors.

Abstract

We introduce a class of lattice gas models of active matter systems whose hydrodynamic description can be derived exactly. We illustrate our approach by considering two systems exhibiting two of the most studied collective behaviours in active matter: the motility-induced phase separation and the transition to collective motion. In both cases, we derive coupled partial differential equation describing the dynamics of the local density and polarization fields and show how they quantitatively predict the emerging properties of the macroscopic lattice gases.