Bremsstrahlung and Fulling-Davies-Unruh thermal bath

Abstract

The bremsstrahlung effect associated with a point charge with constant proper acceleration is discussed from the point of view of the frame coaccelerating with the charge. In this frame the charge is immersed in the so-called Fulling-Davies-Unruh thermal bath. It is shown that the emission of a photon from the source as described by the inertial observer can be interpreted the accelerated frame as either the emission or the absorption of a zero-energy Rindler photon in the thermal bath. It is shown by explicit calculations that the emission rate of photons with fixed transverse momentum in the inertial frame agrees with the combined rate of emission and absorption of zero-energy Rindler photons with the same transverse momentum in the accelerated frame. A discussion on the issue of the detectability of these zero-energy Rindler particles is provided.