Conformally covariant quantization of 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 SO$_0(2,4)$ group and consequently under the de Sitter group. We obtain a new de Sitter invariant two-points 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 $setR^6$ and a moving plane, and on the other hand on a canonical quantization scheme of the Gupta-Bleuler type.