Unruh response functions for scalar fields in de Sitter space

TL;DR

This paper computes the response functions of a detector in de Sitter space for various scalar field couplings, revealing thermal energy distributions despite infrared differences.

Contribution

It provides explicit calculations of Unruh detector responses for scalar fields with different curvature couplings in de Sitter space, including the minimally coupled massless case.

Findings

Detector responses differ in the infrared due to superhorizon mode amplification.

Energy levels are thermally populated regardless of infrared response differences.

Results enhance understanding of quantum field behavior in curved spacetime.

Abstract

We calculate the response functions of a freely falling Unruh detector in de Sitter space coupled to scalar fields of different coupling to the curvature, including the minimally coupled massless case. Although the responses differ strongly in the infrared as a consequence of the amplification of superhorizon modes, the energy levels of the detector are thermally populated.