A DYNAMICAL THEORY OF THE INFINITE RANGE RANDOM ISING MODEL

The dynamics of spin glass is studied in the framework of CTPGF. A marginal stability line is found on the q-X plane. Below T_C with h < h_C, the time evolution of the order parameter follows Fischer's line exponentially to the stability boundary and then decreases in power law along the boundary to its fixed point. The Langevin equation for the spin σ(t) is no longer valid along the stability boundary. The susceptibility is calculated in perturbation theory and found to be in good agreement with those predicted by the projection hypothesis. The general validity of the projection hypothesis is justified in the present formalism.