PARTIAL ANNEALING AND OVERFRUSTRATION IN DISORDERED-SYSTEMS

We study disordered systems with the replica method keeping the number of replicas finite and negative. This is shown to bias the distributi on of samples towards overfrustrated ones. General results on the ther modynamics of such a system is presented. The physical situation descr ibed by this finite-n approach is one where the usually quenched varia bles evolve on long timescales, their evolution being driven by the qu asi-equilibrium correlations of the thermalized variables. In the case of neutral networks this amount to a coupled dynamics of neurons (on fast timescales) and synapses (on longer timescales). The storage capa city of the Hopfield model is shown to be substantially increased by t hese coupled dynamics.