Quantum Larmor radiation in de Sitter spacetime

Abstract

We study the radiation emitted by inertial charge evolving on the expanding de Sitter spacetime. Performing a perturbative calculation, within scalar quantum electrodynamics (sQED), we obtain the transition amplitude for the process and using this we define the energy radiated by the source. In the non-relativistic limit we find that the leading term is compatible with the classical result (Larmor formula). The first quantum correction is found to be negative, a result which is in line with a number of similar quantum field theory results. For the ultra-relativistic case we find a logarithmic divergence of the emitted energy for large frequencies, which we link to the nature of the spacetime. We compare our results with that of Nomura et al. (JCAP 11:013, 2006), where the authors make a similar calculation for a general conformally flat spacetime.

Power radiated by a binary system in a de Sitter universe

“…In this paper, our aim is to calculate the power radiated by a binary system on a de Sitter background. This nicely compliments earlier work on the scalar and electromagnetic radiation emitted by charges on a de Sitter background [15,16,17,18] and radiation from uniformly accelerated charged black holes with Λ > 0 [19]. We restrict ourselves to a binary system whose orbital motion is well-approximated by a circular orbit.…”

“…Taking the high-frequency limit of this result, recovers the result in eq. (18). Quantitatively, the Λ-dependent corrections are extremely small for most physically realistic binary systems and unlikely to play a role in observations that measure power radiated directly.…”

Late-time quantum radiation by a uniformly accelerated detector in de Sitter spacetime

“…The photon emission of a spinless electric charge in de Sitter spacetime has been calculated in Refs. [36,37], along the same line of Refs. [38,39] using the time-dependent perturbation theory in the in-out formalism.…”