Decoupling of fields from escaping sources in a de Sitter Universe

Abstract

The authors explore the behaviour of some field coupled to their respective sources as the latter approach the de Sitter horizon. It is found that the electromagnetic interaction between the source and a typical detector near the origin vanishes as the source is slowly allowed to 'escape' into the horizon. Properties of propagators for a massive vector field, a scalar field and the electromagnetic field are investigated to show how each of these fields in a way decouples from its source resulting in the non-measurability of the associated quantum numbers. This is in contrast to the situation in the Schwarzschild case in which a quasi-static approach of a charge towards the singularity result in a Reisner-Nordstrom black hole. The observer dependence of the decoupling is discussed.