SELF-CONSISTENT T-MATRIX APPROXIMATION TO THE HUBBARD MODEL FOR A FINITE NUMBER OF SITES.

Within the 1D Hubbard model, linear closed chains with various numbers of sites are considered in particle–particle self-consistent random phase approximation (SCRPA) for the T-matrix. Encouraging results with a minimal numerical effort are obtained, confirming earlier results with this theory for other models. SCRPA solves the two-site problem exactly. It therefore contains the two electrons and high density Fermi gas limits correctly. [ABSTRACT FROM AUTHOR]