The Relativistic Point Charge Revisited : Novel Features

Abstract

A fully relativistically covariant formulation of the classical Maxwell electrodynamics of an arbitrarily-moving point charge is presented, purely in terms of gauge invariant potentials without entailing any gauge fixing. A new, relativistically covariant energy-momentum tensor for the radiation fields is derived and yields results for the angular power distribution, in full agreement with results derived in a frame-dependent manner in standard texts of classical electrodynamics. This is then used to present a full derivation, not available in standard texts, of the energy-momentum and orbital angular momentum of a relativistic point charge. Radiation backreaction is turned on and the system reanalyzed Lorentz-covariantly, including effects of mass renormalization. This leads us to reiterate earlier conclusions regarding the inherent inadequacy of classical Maxwell electrodynamics. The Abraham-Lorentz equation is derived en passant in appropriate limits without requiring any extraneous structural artifact, and the Landau-Lifschitz proposal for modification of the theory is also critically reviewed.

12 pages, Latex, Author Zahid Ansari's name included for his contribution to subsection 2B; Section 2 of version v2 removed; new subsection 2C on radiant orbital angular momentum 2C added