Collective Turns in Spinless Flocks

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.