QED effects in helium and comparisons with high precision experiment

A large body of work to calculate nonrelativistic energies, relativistic corrections, and quantum electrodynamic (QED) energy shifts in helium is reviewed and compared with experiment. Of particular significance are measurements of the QED (Lamb) shift for the low-lying S-states of helium, where the accuracy rivals the best measurements in the corresponding He+ hydrogenic ion. Progress in a program to extract a value for the fine structure constant alpha from a comparison between theory and experiment for the fine structure splittings of the helium 2 P-3(J) manifold of states is discussed. Extensions to three-electron systems such as lithium are briefly summarized.