Photon retinue and infra-red divergence problem in quantum electrodynamics

Abstract

This paper is a careful study of the infra-red divergence problem in quantum electrodynamics. It is found that the conventional treatments of this problem are not consistent with the concept of the photon as a real physical object and it is held here that the problem is a physical one rather than merely one of computational technique. By taking into account the cohesive photon retinue induced by the electron, it is shown that, for any definite number of soft-photon emissions, the cross-sections are always divergence-free. The precise physical significance of the photon retinue in connection with experimental measurement is also discussed.