NEW DIAGRAM TECHNIQUE FOR PERIODIC ANDERSON MODEL

A new diagram technique, previously proposed for Hubbard Model, was us ed for Periodic Anderson Model (PAM). The Hamiltonian off-localized el ectrons and of free conduction electrons are considered as a main part of Hamiltonian of PAM and the hybridization term is treated as a pert urbation. This diagram technique is used for Matsubara Green functions and contains apart from the Wick product of free Green functions new contributions equal to on-site cumulants depending on the Coulomb inte raction.