Photon propagator in de Sitter space in the general covariant gauge

0579705 - FZÚ 2024 RIV DE eng J - Journal Article
Glavan, Dražen - Prokopec, T.
Photon propagator in de Sitter space in the general covariant gauge.
Journal of High Energy Physics. Roč. 2023, č. 5 (2023), č. článku 126. ISSN 1029-8479. E-ISSN 1029-8479
R&D Projects: GA ČR(CZ) GA20-28525S
Institutional support: RVO:68378271
Keywords : de Sitter space * early universe particle physics * gauge symmetry * non- equilibrium field theory
OECD category: Particles and field physics
Impact factor: 5.4, year: 2022
Method of publishing: Open access

We consider a free photon field in D-dimensional de Sitter space, and construct its propagator in the general covariant gauge. Canonical quantization is employed to define the system starting from the classical theory. This guarantees that the propagator satisfies both the equation of motion and subsidiary conditions descending from gauge invariance and gauge fixing. We first construct the propagator as a sum-over-modes in momentum space, carefully accounting for symmetry properties of the state. We then derive the position space propagator in a covariant representation, that is our main result. Our conclusions disagree with previous results as we find that the position space photon propagator necessarily breaks de Sitter symmetry, except in the exact transverse gauge limit.

Permanent Link: https://hdl.handle.net/11104/0348511