  We perform extensive simulations of a binary mixture Lennard-Jones system
subjected to a temperature jump in order to study the time evolution of
fluctuations during aging. Analyzing data from 1500 different aging
realizations, we calculate distributions of inherent structure energies for
different aging times and contrast them with equilibrium. We find that the
distributions initially become narrower and then widen as the system
equilibrates. For deep quenches, fluctuations in the glassy system differ
significantly from those observed in equilibrium. Simulation results are
partially captured by theoretical predictions only when the final temperature
is higher than the mode coupling temperature.
