NONEQUILIBRIUM DYNAMICS OF A SIMPLE STOCHASTIC-MODEL

We investigate the low-temperature dynamics of a simple stochastic mod el, introduced recently in the context of the physics of glasses. The slowest characteristic time at equilibrium diverges exponentially at l ow temperature. On smaller time scales, the non-equilibrium dynamics o f the system exhibits an aging regime. We present an analytical study of the scaling behaviour of the mean energy, of its local correlation and response functions, and of the associated fluctuation-dissipation ratio throughout the regime of low temperature and long times. This an alysis includes the aging regime, the convergence to equilibrium, and the crossover behaviour between them.