Conformally covariant quantization of the Maxwell field in de Sitter space

In this article, we quantize the Maxwell (“massless spin one”) de Sitter field in a conformally invariant gauge. This quantization is invariant under the ${\mathrm{SO}}_0(2,4)$ group and consequently under the de Sitter group. We obtain a new de Sitter-invariant two-point function which is very simple. Our method relies on the one hand on a geometrical point of view which uses the realization of Minkowski, de Sitter and anti-de Sitter spaces as intersections of the null cone in ${\mathbb{R}}^6$ and a moving plane, and on the other hand on a canonical quantization scheme of the Gupta-Bleuler type.