LEVEL CURVATURES, SPECTRAL STATISTICS AND SCALING FOR INTERACTING PARTICLES

The mobility of two interacting particles in a random potential is stu died, using the sensitivity of their levels to a change of boundary co nditions. The delocalization in Hilbert space induced by the interacti on of the two particle Pock states is shown to decrease the mobility i n metals and to increase it in insulators. In contrast to the single p article case, the spectral rigidity is not directly related to the lev el curvature. Therefore, another curvature of topological origin is in troduced, which defines the energy scale below which the spectrum has the universal Wigner-Dyson rigidity.