Relevance of Metric-Free Interactions in Flocking Phenomena

TL;DR

This paper demonstrates that metric-free, topological interactions fundamentally alter flocking behavior in self-propelled particles, suggesting more realistic models for collective animal and cell movement should incorporate these interactions.

Contribution

It introduces and analyzes a minimal model with metric-free, topological interactions, highlighting their importance over traditional metric-based models in collective motion.

Findings

Metric-free interactions lead to different collective properties.

Models incorporating topological neighbors better match biological observations.

Relevance extends to modeling cells, birds, and fish.

Abstract

We show that the collective properties of self-propelled particles aligning with their "topological" (Voronoi) neighbors are qualitatively different from those of usual models where metric interaction ranges are used. This relevance of metric-free interactions, shown in a minimal setting, indicate that realistic models for the cohesive motion of cells, bird flocks, and fish schools may have to incorporate them, as suggested by recent observations.