Equilibrium and nonequilibrium fluctuations in a glass-forming liquid.

Glass-forming liquids display strong fluctuations-dynamical heterogeneities-near their glass transition. By numerically simulating a binary Weeks-Chandler-Andersen liquid and varying both temperature and time scale, we investigate the probability distributions of two kinds of local fluctuations in the nonequilibrium (aging) regime and in the equilibrium regime, and find them to be very similar in the two regimes and across temperatures. We also observe that, when appropriately rescaled, the integrated dynamic susceptibility is very weakly dependent on temperature and very similar in both regimes.