Dephasing time in disordered systems

We show that interaction effects give rise to a cutoff 1ph in the "diffusion," the basic propagator of the disordered interacting electron gas. We calculate 1ph to lowest order in the disorder but to all orders in the interaction, and exhibit its relation to the scaling variables of the disordered-interacting-electron problem. This framework provides an explanation for the anomalous enhancement of inelastic processes which is observed experimentally in systems close to the metal-insulator transition.