Off-equilibrium effective temperature in monatomic Lennard-Jones glass

The off-equilibrium dynamics of a monatomic Lennard-Jones glass is numerically investigated after sudden isothermal density jumps (crunch) from well equilibrated liquid configurations towards the glassy state. The generalized fluctuation-dissipation relation has been studied and the temperature dependence of the violation factor m is found in agreement with the one step replica symmetry breaking scenario, i.e., at low temperature m(T) is found proportional to T up to an off-equilibrium effective temperature T-eff, where m(T-eff) = 1. We report T-eff as a function of the density and compare it with the glass transition temperature T-g as determined by equilibrium calculations.