Relativistic and QED effects in highly ionized systems

This paper provides an overview of the theoretical techniques for incorporating relativistic and QED effects in few electron systems. The energies of one-electron systems are discussed. Lamb shift theory is summarized, and calculations, recent contributions to the theory, comparison with experiments, and the most significant points emerging from the comparison are given. These results are compared with light muonic systems. The extension to two and three electron systems is discussed, and the relativistic Hartree-Fock calculations and Z-1 expansion calculations summarized. Finally, a method for including relativistic effects in the theory of radiative transitions is presented