The electron gas with short coherence length pairs: how to approach the stronger coupling limit?

The attractive Hubbard model is investigated in 2D using a T-matrix approac h. In a self-consistent calculation pairs as infinite lifetime Bosons only exist in the atomic limit and therefore a Fermi surface can be investigated also in the stronger coupling regime. A heavy quasiparticle peak with a we ak dispersion crosses the Fermi surface at k(F) whereas light, single parti cle excitations do only exist far away from the Fermi surface. At low tempe ratures there seem to exist different self-consistent solutions. In one of them a pseudogap opens even in the integrated density of states. In the pre sent work accurate k-dependent and k-integrated spectral quantities for a 2 D finite lattice are presented. (C) 2001 Elsevier Science B.V. All rights r eserved.