Radiation reaction and the acceleration-dependent mass increase of a charged sphere undergoing uniform acceleration

TL;DR

This paper investigates the self-force on a uniformly accelerated charged sphere, revealing an acceleration-dependent mass increase that explains photon energy emission during acceleration.

Contribution

It introduces a new factor  that accounts for an acceleration-dependent mass increase, providing a novel explanation for photon energy emission.

Findings

The self-force converges to the radiation reaction for large acceleration.

An acceleration-dependent mass increase () explains photon energy origin.

More energy is required to accelerate the sphere due to increased effective mass.

Abstract

Photon emission from a uniformly accelerated charge is among the most mysterious physical phenomena. Theories based on the Lorentz-Abraham-Dirac equation mostly conclude that a uniformly accelerated point charge cannot feel radiation reaction. Such a conclusion suggests that the origin of the photon energy is unclear. In this paper, we determine the self-force of a uniformly accelerated charged sphere using the Lorentz force equation, with an assumption that the sphere is Lorentz-contracted during the acceleration. For large acceleration, the calculated self-force converges to the radiation reaction (given by the Larmor formula) via a new factor $\gamma_{a}$, which describes an acceleration-dependent increase in the effective mass. This increased mass makes it harder to accelerate the particle (compared to a point-charge), which means more energy should be provided to the particle in order to get the expected acceleration. This extra energy can be interpreted as the origin of the photon energy.