MONTE-CARLO SIMULATION OF UNIVERSAL SHORT-TIME BEHAVIOR IN CRITICAL RELAXATION

The time evolution of the three-dimensional critical Ising model relax ing from a non-equilibrium initial state is studied by means of Monte Carlo simulation. We observe the characteristic initial increase of th e (spatially) averaged magnetization predicted by Janssen et al. The e xponent theta' that governs the initial behaviour is determined, and t he dependence of the long-time linear decay on the initial magnetizati on, m0, is analysed. Our simulation corroborates earlier results deriv ed from continuum models.