Interaction between Maxwell field and charged scalar field in de Sitter universe

TL;DR

This paper investigates how charged scalar and Maxwell fields interact in a de Sitter universe, deriving scattering amplitudes and analyzing particle and pair production effects, which are significant only in strong gravitational fields.

Contribution

It constructs the formalism for interacting fields in de Sitter space and derives the perturbation expansion for scattering amplitudes, focusing on particle and pair production phenomena.

Findings

Particle production from de Sitter vacuum analyzed

Pair production in external fields studied

Effects vanish in flat spacetime limit

Abstract

We study the theory of interaction between charged scalar field and Maxwell field in de Sitter background. Solving the equation of interacting fields we define the in-out fields as asymptotic free fields and construct the reduction formalism for scalar field. Then we derive the perturbation expansion of the scattering operator. The first order transition amplitudes corresponding to particle production from de Sitter vacuum and pair production in an external field are analysed. We show that all these effects are important only in strong gravitational fields and vanish in the flat limit.