Sound Waves and the Absence of Galilean Invariance in Flocks
Sound Waves and the Absence of Galilean Invariance in Flocks
We study a model of flocking for a very large system (N=320,000) numerically. We find that in the long wavelength, long time limit, the fluctuations of the velocity and density fields are carried by propagating sound modes, whose dispersion and damping agree quantitatively with the predictions of our previous work …