Kovacs-like memory effect in driven granular gases

TL;DR

This paper demonstrates that memory effects, similar to Kovacs effects in glasses, are present in dilute driven granular gases, showing non-monotonic temperature evolution influenced by dissipation strength.

Contribution

It reveals the presence of Kovacs-like memory effects in dilute granular gases through analytical and simulation methods, highlighting the role of dissipation.

Findings

Normal Kovacs hump at weak dissipation

Reversed Kovacs hump at strong dissipation

Memory effects are intrinsic to dilute granular gases

Abstract

While memory effects have been reported for dense enough disordered systems such as glasses, we show here by a combination of analytical and simulation techniques that they are also intrinsic to the dynamics of dilute granular gases. By means of a certain driving protocol, we prepare the gas in a state where the granular temperature $T$ coincides with its long time limit. However, $T$ does not subsequently remain constant, but exhibits a non-monotonic evolution before reaching its non-equilibrium steady value. The corresponding so-called Kovacs hump displays a normal behavior for weak dissipation (as observed in molecular systems), but is reversed under strong dissipation, where it thus becomes anomalous.