Semiclassical gravitational effects in de Sitter space at finite temperature

Abstract

In the framework of finite-temperature conformal scalar field theory on de Sitter spacetime the linearized Einstein equations for the renormalized stress tensor are solved exactly. In this theory quantum field fluctuations are concentrated near two spheres of the de Sitter radius, propagating as light wavefronts. The analysis, performed for a flat expanding universe, shows exponential damping of the back-reaction effects far from these spherical objects. The solutions obtained for the semiclassical Einstein equations in a de Sitter background can also be extended straightforwardly to the anti-de-Sitter geometry.