Radiation reaction from quantum electrodynamics and its implications for the Unruh effect

TL;DR

This paper rederives the Abraham-Lorentz-Dirac radiation reaction force from quantum electrodynamics and investigates its implications for uniformly accelerated charges, revealing that absorption and stimulated emission effects cancel out, resulting in no net radiation reaction.

Contribution

It provides a quantum electrodynamics derivation of radiation reaction and explores its behavior under uniform acceleration, linking it to the Unruh effect.

Findings

Absorption of photons due to the Unruh effect occurs in the accelerated frame.

Stimulated emission also occurs alongside photon absorption.

The net effect on the charge's motion is zero due to cancellation.

Abstract

The Abraham-Lorentz-Dirac theory predicts vanishing radiation reaction for uniformly accelerated charges. However, since an accelerating observer should detect thermal radiation, the charge should be seen absorbing photons in the accelerated frame which, if nothing else occurs, would influence its motion. This means that either there is radiation reaction seen in an inertial frame or there should be an additional phenomenon seen in the accelerated frame countering the effect of absorption. In this paper I rederive the Abraham--Lorentz--Dirac force from quantum electrodynamics, then I study the case of a uniformly accelerated charge. I show that in the accelerated frame, in addition to the absorption of photons due to the Unruh effect there should also be stimulated emission. The net effect of these phenomena on the motion of the charge is found to be zero.