Long-time tails in the velocity autocorrelation function of hard-rod binary mixtures

Abstract

The temporal evolution of binary mixtures of hard rods in a ring is simulated in a computer with random initial velocities ±v. The time the system takes to reach a Maxwellian distribution dramatically diverges as the mass ratio ε→1 and it also increases, although rather slowly, when ε→∞. A negative ‘‘long-time tail,’’ i.e., a slow, power-law decay in the velocity autocorrelation function at large values of the time t, is observed whose behavior changes from t − 3 to t − δ , δ≲1, as ε is increased from ε=1. .AE