Si trova su / Altri legami
© 2021 Institute of Physics Publishing. All rights reserved.Model systems of self–propelled particles reproduce many phenomena observed in laboratory active matter systems that defy our thermal equilibrium–based intuition. In particular, in stationary states of self–propelled systems, it is recognized that velocities of different particles exhibit non–trivial equal–time correlations. Such correlations are absent in equivalent equilibrium systems. Recently, researchers found that the range of the velocity correlations increases with increasing persistence time of the self–propulsion and can extend over many particle diameters. Here we review the initial studies of long–ranged velocity correlations in solid–like systems of self–propelled particles. Then, we demonstrate that the long–ranged velocity correlations are also present in dense fluid–like systems. We show that the range of velocity correlations in dense systems of self–propelled particles is determined by the combination of the self–propulsion and the virial bulk modulus that originates from repulsive interparticle interactions.
