By numerical simulation of a Lennard-Jones-like liquid driven by a velocity gradient $\gamma$ we test the fluctuation relation (FR) below the (numerical) glass transition temperature $T_g$. We show that, in this region, the FR deserves to be generalized introducing a numerical factor $X(T,\gamma )<1$ that defines an “effective temperature” $T_{\mathit{FR}}=T∕X$. On the same system we also measure the effective temperature $T_{\mathit{eff}}$, as defined from the generalized fluctuation-dissipation relation, and find a qualitative agreement between the two different nonequilibrium temperatures.

• Received 7 April 2004

DOI:https://doi.org/10.1103/PhysRevE.71.020101