Discussion on the onset of antiferromagnetism in the hubbard model

Abstract
We calculate the response to a periodical external magnetic field of the magnetically disordered phase of the Hubbard model in the alloy analogy approximation. We investigate the behaviour of the q-dependent susceptibility and in particular we look for a possible divergence of the susceptibility for a wave-vector corresponding to an antiferromagnetic ordering. We do not find any instability for a half-filled or nearly half-filled band