Density of states for the Anderson model

The Anderson model is studied in the limit U to infinity using a Green function decoupling procedure. It is shown that the solution gives the correct results in the intermediate valence case, and in the Kondo limit, at low and high temperatures: for the intermediate valence case, the position of the virtual d level is obtained as a function of temperature; for the Kondo case it is shown that the density of states has a peak of width TK at the Fermi level, which disappears above the Kondo temperature.