On ``gauge renormalization'' in classical electrodynamics (Q2505240)

The author commences by pointing out that there are difficulties in establishing what exactly the energy-momentum tensor describes. He points out that an extra term is needed in this when charge is present. He derives the energy balance equation for the bound electromagnetic field of a charged particle and shows that there is a vagueness in the total energy and total momentum of the electromagnetic field of a single particle. A new electromagnetic tensor is introduced which satisfies the conservation laws. Two divergent integrals are obtained, the difference of which is finite and gives the electromagnetic mass and momentum of a particle. The equations of motion for both a non-radiating and a radiating charged particle are obtained, together with expressions for the force of radiation reaction. There is a treatment of the energy flux and momentum for both free and bound electromagnetic fields, the energy flux being expressed in terms of a generalized Umov vector.