T. Wegner et al., TEMPERATURE-DEPENDENT ELECTRONIC-STRUCTURE AND FERROMAGNETISM IN THE D=INFINITY HUBBARD-MODEL STUDIED BY A MODIFIED PERTURBATION-THEORY, Physical review. B, Condensed matter, 57(11), 1998, pp. 6211-6214
The infinite-dimensional Hubbard model is studied by means of a modifi
ed perturbation theory. The approach reduces to the iterative perturba
tion theory for weak coupling. It is exact in the atomic limit and cor
rectly reproduces the dispersions and the weights of the Hubbard bands
in the strong-coupling regime for arbitrary fillings. Results are pre
sented for the hypercubic and an fee-type lattice. For the latter we f
ind ferromagnetic solutions. The filling-dependent Curie temperature i
s compared with the results of a recent quantum Monte Carlo study.