RELATIVISTIC THEORY OF THE LAMB SHIFT IN SELF-FIELD QUANTUM ELECTRODYNAMICS

The self-field QED is based on a nonlinear action in the psi-field alone obtained by eliminating the electromagnetic field A(mu). This approach, previously applied to spontaneous emission, vacuum polarization, and g - 2 and to the low-energy part of the Lamb shift, is here extended to the fully relativistic calculation of the Lamb shift. It is shown that, to first order of iteration, it gives the same result as the quantized theory of Mohr [Ann. Phys. (N.Y.) 88, 26 (1974); 88, 52 (1974)]. The renormalization procedure is different and simpler.