Perturbational approach to the one particle properties of the Hubbard model

It is shown that the Hubbard model can be viewed as limiting case of a periodic Anderson model. This relation is used to set up a perturbation theory for the Hubbard model with the transfermatrixelementt as expansion parameter. One particle properties of the three dimensional Hubbard model in the half filled band case for several values of the local Coulomb interactionU calculated with this method are presented. The results give clear hints towards the formation of a gap in the excitation spectrum. The variation of the free energy on the model parameters is found to be in good agreement with expectations.This work was performed within the research program of SFB 252 Elektronisch hochkorrelierte metallische Materialien