Abstract
Physical interactions generally respect certain symmetries, such as reciprocity and energy conservation, whichsurvive in coarse-grained isothermal descriptions. Active many-body systems usually break such symmetriesintrinsically, on the particle level, so that their collective behavior is often more naturally interpreted as a resultof information exchange.
Here we study numerically how information spreads from a "leader" particle throughan initially aligned flock, described by the Vicsek model without noise. In the low-speed limit of a static spinlattice, we find purely conductive spreading, reminiscent of heat transfer.
Swarm motility and heterogeneity canbreak reciprocity and spin conservation. But what seems more consequential for the swarm response is that thedispersion relation acquires a significant convective contribution along the leader's direction of motion.