Effects of Electron-Electron Interactions on the Bandwidth of Simple Metals

Abstract

Although it is popular because it reduces the occupied bandwidth of sodium in agreement with photoemission experiments, the GW approximation or its modification by Hubbard does not give a qualitatively accurate wavenumber dependence of the self-energy correction for the electron liquid over a wide range of wavenumbers throughout the entire region of metallic densities. We show that an accurate theory of the electron liquid increases the occupied bandwidth in contradiction to the usual interpretation of photoemission experiments.