Discrete symmetries determining scalar quantum modes on the de Sitter spacetime

TL;DR

This paper investigates how discrete symmetries influence scalar quantum modes in de Sitter spacetime, proposing symmetry invariance as a criterion for vacuum selection and analyzing implications for thermal effects.

Contribution

It introduces a symmetry-based criterion for selecting vacua in de Sitter space and compares its implications with existing approaches in the literature.

Findings

Symmetry invariance can determine preferred vacuum states.

Different symmetry choices affect eigenfunctions and thermal properties.

Comparison with previous vacua choices highlights new insights.

Abstract

The action of the discrete symmetries on the scalar mode functions of the de Sitter spacetime is studied. The invariance with respect to a combination of discrete symmetries is put forward as a criterion to select a certain vacuum out of a family of vacua. The implications of the choices for eigenfunctions of various common sets of commuting operators are explored, and the results are compared to the different original choices from the literature that have been utilized in order to exhibit thermal effects.