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 $m\left(T\right)$ is found proportional to $T$ up to an off-equilibrium effective temperature $T_{\mathrm{eff}}$, where $m\left(T_{\mathrm{eff}}\right)=1\mathrm{}$. We report $T_{\mathrm{eff}}$ as a function of the density and compare it with the glass transition temperature $T_g$ as determined by equilibrium calculations.