Strong non-exponential relaxation and memory effects in a fluid with non-linear drag

Abstract

We analyse the dynamical evolution of a fluid with non-linear drag, for which binary collisions are elastic, at the kinetic level of description. When quenched to low temperatures, the system displays a really complex behaviour. The glassy response of the system is controlled by a long-lived nonequilibrium state, and includes non-exponential, algebraic, relaxation and strong memory effects in the time evolution of its kinetic temperature. Moreover, the observed behaviour is universal, in the sense that the time evolution of the temperature-for both relaxation and memory effects-falls onto a master curve, regardless of the details of the experiment. Our theoretical predictions are checked against simulations of the kinetic equation, and an excellent agreement is found.