Collective Dynamics of Deformable Self-Propelled Particles with Repulsive Interaction

TL;DR

This paper studies how deformable self-propelled particles with repulsive interactions exhibit collective motion that becomes unstable at high densities, revealing a novel transition caused by a saddle-node bifurcation.

Contribution

It introduces a mean field analysis of deformable particles showing a new type of transition in collective behavior due to deformability.

Findings

Collective motion appears in two dimensions.

Ordered state becomes unstable beyond a critical density.

Transition caused by saddle-node bifurcation.

Abstract

We investigate dynamics of deformable self-propelled particles with a repulsive interaction whose magnitude depends on the relative direction of elongation of a pair of particles. A collective motion of the particles appears in two dimensions. However this ordered state becomes unstable when the particle density exceeds a certain critical threshold and the dynamics becomes disorder. We show by a mean field analysis that this novel transition characteristic to deformability occurs due to a saddle-node bifurcation.