Nonrelativistic Perturbation Theory

Abstract

It is now time to expand the formal nonrelativistic scattering equations into perturbation series and apply them to simple atomic and solid-state problems. First we review time-independent perturbation expansions and extend them to the time-dependent case. The use of scattering diagrams will allow us to develop some intuition for this transition. Next we apply the theory to the interaction of radiation with matter, i.e., to the scattering of photons and bound atomic electrons. Finally we consider the scattering of phonons and electrons in solids, developing scattering diagrams which parallel the atomic diagrams as much as possible.