Über die kovariante Quantisierung des elektrodynamischen Feldes bei nichtverschwindender Photonmasse

Abstract

It is shown that an old and well-known difficulty in quantum electrodynamics concerning the particle interpretation can be avoided. This is done by the formal introduction of a finite photon rest mass, and by using an expansion of the electro-dynamic potentials into one-particle eigenfunctions instead of the usual expansion into transverse, longitudinal, and scalar waves.