Collective Turns in Spinless Flocks

TL;DR

This paper presents a minimal model explaining how non-reciprocal local interactions enable efficient information transfer during collective turns in flocks, with analytical and scattering predictions applicable to other physical systems.

Contribution

It introduces a novel aggregation-based model highlighting non-reciprocal interactions as key to flock turning dynamics, supported by perturbative analysis and wave scattering insights.

Findings

Velocity fluctuations described by a Born approximation

Wave scattering occurs during information transfer

Model makes testable predictions for flock behavior

Abstract

Using a minimal aggregation-based model, we address the efficient information transfer observed in natural flocks during collective turns. Specifically, we demonstrate that this feature can arise solely from the non-reciprocal nature of local interactions. Through a perturbative analysis, moreover, we find that velocity fluctuations (in the continuum) can be described by a Born approximation. We then show that a wave propagating across the flock undergoes scattering. Our model provides testable predictions and can be extended to study other physical contexts exhibiting polar order.