Single Particle Green's Function in the Electron–Plasmon Approximation

Abstract

A discussion of how to carry out a direct perturbation expansion for the one-electron Green's function is given using an electron–plasmon model for the conduction electron correlations. A crucial feature of the method is the consistent extraction of energy shifts. Numerical results for the spectral function and the density of states are given in lowest order and the generalization to higher order is discussed. The present work differs from previous ones in that the method used cannot give rise to "plasmaron"-like excitations. Other singular features also come in differently.