Pattern formation in self-propelled particles with density-dependent motility

TL;DR

This paper investigates how self-propelled particles with density-dependent motility form various patterns such as clumps, lanes, and asters through simulations and hydrodynamic analysis, explaining phenomena observed in experiments.

Contribution

It introduces a combined simulation and hydrodynamic approach to explain pattern formation in particles with density-dependent motility, a novel mechanism in active matter research.

Findings

Formation of moving clumps, lanes, and asters

Density-dependent motility leads to diverse patterns

Mechanism explains experimental observations

Abstract

We study the behaviour of interacting self-propelled particles, whose self-propulsion speed decreases with their local density. By combining direct simulations of the microscopic model with an analysis of the hydrodynamic equations obtained by explicitly coarse graining the model, we show that interactions lead generically to the formation of a host of patterns, including moving clumps, active lanes and asters. This general mechanism could explain many of the patterns seen in recent experiments and simulations.