Strong electronic correlations pose one of the biggest challenges to solid state theory.
Recently developed methods that address this problem by starting with the local, eminently …

This article reviews quantum cluster theories, a set of approximations for infinite lattice
models which treat correlations within the cluster explicitly, and correlations at longer length …

We calculate the spectral weight of the one-and two-dimensional Hubbard models by
performing exact diagonalizations of finite clusters and treating intercluster hop** with …

Cluster perturbation theory is a technique for calculating the spectral weight of Hubbard
models of strongly correlated electrons, which combines exact diagonalizations on small …

This is a short review of the theoretical work on the two-dimensional Hubbard model
performed in Sherbrooke in the last few years. It is written on the occasion of the twentieth …

We critique a Padé analytic continuation method whereby a rational polynomial function is fit
to a set of input points by means of a single matrix inversion. This procedure is …

We develop a general theory of a boson decomposition for both local and non-local
interactions in lattice fermion models which allows us to describe fermionic degrees of …

We present a strong-coupling expansion of the Bose-Hubbard model which describes both
the superfluid and the Mott phases of ultracold bosonic atoms in an optical lattice. By …

Based on the self-energy-functional approach proposed recently [M. Potthoff, Eur. Phys. J. B
32, 429 (2003)], we present an extension of the cluster-perturbation theory to systems with …

The strong-coupling perturbation theory of the Hubbard model is presented and carried out
to order (t/U) 5 for the one-particle Green function in arbitrary dimension. The spectral weight …