Title: Asymmetric Hubbard model within generating functional approach in dynamical mean field theory
Author(s):

	I.V.Stasyuk (Institute for Condensed Matter Physics of the National Academy of Sciences of Ukraine, 1 Svientsitskii Str., 79011 Lviv, Ukraine) ,
	O.B.Hera (Institute for Condensed Matter Physics of the National Academy of Sciences of Ukraine, 1 Svientsitskii Str., 79011 Lviv, Ukraine)

In the paper a new analytic approach to the solution of the effective single-site problem in the dynamical mean field theory is developed. The approach is based on the method of the Kadanoff-Baym generating functional in the form developed by Izyumov et al. It makes it possible to obtain a closed equation in functional derivatives for the irreducible part of the single-site particle Green's function; the solution is constructed iteratively. As an application of the proposed approach the asymmetric Hubbard model (AHM) is considered. The inverse irreducible part Ξ^-1_σ of the single-site Green's function is constructed in the linear approximation with respect to the coherent potential J_σ. Basing on the obtained result, the Green's function of itinerant particles in the Falicov-Kimball limit of AHM is considered, and the decoupling schemes in the equations of motion approach (GH3 approximation, decoupling by Jeschke and Kotliar) are analysed.

Key words: strongly correlated systems, asymmetric Hubbard model, single-site problem, dynamical mean field theory

PACS: 71.10.Fd, 71.27.+a, 71.30.+h