Frequency-Dependent Polarizability of Atomic Oxygen Calculated by Many-Body Theory

Abstract

The use of many-body perturbation theory with time-dependent perturbations is reviewed and applied to a calculation of the frequency-dependent polarizability $\ensuremath{\alpha}(\ensuremath{\omega})$ of atomic oxygen. The poles of $\ensuremath{\alpha}(\ensuremath{\omega})$ are in reasonable agreement with the experimental excitation energies when diagrams beyond second order are included.