Uniform Acceleration Radiation

Abstract

Radiation of a uniformly accelerating source is an enduring problem in the physics literature that gives rise to multiple apparent paradoxes. Also in the literature there exist several notions for defining radiation. Here we focus on exploring the Poynting flux radiation, which is defined with respect to an observer’s proper timelike Killing vector, of a source in a massless scalar field. We fill in details regarding the vanishing divergence condition of the stress tensor and verify explicitly that the divergence vanishes on the past horizon. Using a convenient set of coordinates, we plot vector fields of the Minkowski Poynting vector flux to gain insight into the flow of energy of the system. We then address implications to the equivalence principle paradox for uniformly accelerating sources, and argue that the qualitative equivalence principle provides the correct argument to ‘save’ the equivalence principle for scalar electrodynamics. We also provide a criterion, which would quantitatively verify this, if proven.