Functional integral approach to the Falicov-Kimball model.

Abstract

Using the functional integral method of Hubbard-Stratonovich, we have studied the existence of first order phase transitions in the Falicov-KimbalI model. By means of two different approximation we have obtained results at variance. The first approximation, that we called uniform, is like a mean field one; and the second, a self consistent one, is similar to the coherent potential approximation.