Quasiparticle properties of the two-dimensional Hubbard model in a propagator-renormalized fluctuation-exchange approximation

We calculate the self-energy and thermodynamic potential of the two-dimensional Hubbard model in a propagator-renormalized conserving approximation, for lattices as large as 128\ifmmode\times\else\texttimes\fi{}128 and temperatures as low as 0.002 times the bandwidth. For densities near quarter filling we see no evidence of deviations from the predictions of Fermi-liquid theory, such as those expected in a Luttinger liquid or a marginal Fermi liquid.