Slave-boson calculation of the Landau parameters of the one-band Hubbard model

We present a microscopic slave-boson calculation of the three Landau parameters F₀^s, F₀^a, and F₁^s of the Hubbard model for any strength of the interaction U and any filling δ=1-n. The Landau parameter F₁^a is then obtained by using the s-p approximation on the forward-scattering sum rule for the Landau parameters. General analytic expressions are given for the four Landau parameters and related observables. Simple asymptotic expressions for these quantities in four interesting regimes on the U,δ manifold are presented. We also show the results of numerical calculations of these quantities for the full range of U and δ for a system with a flat density of states, which are then compared with the experimental results for normal ³He. We find good agreement with the experimentally deduced Landau parameters for both the half-filled-band model and the δ-dependent model at reasonable values of U and δ.