New approach to many-body quantum-electrodynamics calculations:merging quantum electrodynamics with many-body perturbation

Abstract

A new method for bound-state quantum electrodynamics (QED) calculations on many-electron systems is presented that is a combination of the non-QED many-body technique for quasi-degenerate systems and the newly developed covariant-evolution-operator technique for QED calculations. The latter technique has been successfully applied to the fine structure of excited states of medium-heavy heliumlike ions, and it is expected that the new method should be applicable also to light elements, hopefully down to neutral helium. PACS Nos.: 31.30.Jv, 31.15.Md, 31.25.Jf, 33.15.Pw