DENSITIES OF STATES IN THE PERIODIC ANDERSON MODEL

The densities of states for the periodic Anderson model are evaluated by means of a non-standard perturbation expansion in the kinetic term of the conduction electrons. The calculations are performed at finite temperature, taking into account in an exact way the effect of the on-site Coulomb repulsion U and the hybridization coupling V. We reproduce most of the properties that are usually expected for the correlated electrons, especially the peaks in the density of states at energies epsilon-f and epsilon-f + U and the double peak structure with the hybridization gap in the region around the chemical potential.