Quasinormal modes in pure de sitter spacetimes

TL;DR

This paper investigates quasinormal modes of scalar and fermion perturbations in pure de Sitter spacetimes, revealing dimension-dependent existence conditions and differences in mode behavior across dimensions.

Contribution

It provides the first detailed analysis of quasinormal modes for both scalar and fermion fields in pure de Sitter spaces, highlighting the impact of spacetime dimensionality.

Findings

Scalar quasinormal modes exist for masses greater than (d-1)/(2l).

No s-wave fermion quasinormal modes in 3D de Sitter space.

Dimensionality influences the existence and properties of quasinormal modes.

Abstract

We have studied scalar perturbations as well as fermion perturbations in pure de Sitter space-times. For scalar perturbations we have showed that well-defined quasinormal modes can exist provided that the mass of scalar field $m>\frac{d-1}{2l}$. The quasinormal frequencies of fermion perturbations in three and four dimensional cases have also been presented. We found that different from other dimensional cases, in three dimensional pure de Sitter spacetime there is no quasinormal mode for the s-wave. This interesting difference caused by the spacial dimensions is true for both scalar and fermion perturbations.