DYNAMICAL REPLICA THEORY FOR DISORDERED SPIN SYSTEMS

We present a method to solve the dynamics of disordered spin systems o n finite time scales. It involves a closed driven diffusion equation f or the joint spin-field distribution, with time-dependent coefficients described by a dynamical replica theory which, in the case of detaile d balance, incorporates equilibrium replica theory as a stationary sta te. The theory is exact in various limits. We apply our theory to both the symmetric and the nonsymmetric Sherrington-Kirkpatrick spin glass , and show that it describes the (numerical) experiments very well.