Abstract
In this Letter we investigate the approach to equilibrium in fragile glasses by doing numerical simulations of binary mixtures. We study the diffusion of particles and the response to an external driving force. We find evidence for the validity of the Cugliandolo-Kurchan off-equilibrium fluctuation-dissipation relation. The results agree with the predictions of one step replica symmetry breaking and the dependence of the breakpoint parameter on temperature coincides with that found in simple generalized spin glass models.