Quasinormal modes of D-dimensional de Sitter spacetime

TL;DR

This work delivers exact analytic quasinormal frequencies for electromagnetic, gravitational, and real massive scalar fields in $D$-dimensional de Sitter spacetime ($D\ge4$). By solving hypergeometric-type radial equations and enforcing regularity at the origin along with purely outgoing behavior at the cosmological horizon, the authors derive two frequency families for each field type and demonstrate that QNMs exist in both even and odd dimensions, contrary to some earlier claims. Massless fields yield purely imaginary frequencies, while massive fields produce complex spectra with dependencies on $D$, $l$, and the curvature coupling; special couplings yield additional spectroscopic structures. The results refine understanding of field dynamics in higher-dimensional de Sitter backgrounds and have implications for dS/CFT and related analyses. All mathematical expressions are presented with exact $LaTeX$-style notation wrapped in $...$ for precise readability.

Abstract

We calculate the exact values of the quasinormal frequencies for an electromagnetic field and a gravitational perturbation moving in $D$-dimensional de Sitter spacetime ($D \geq 4$). We also study the quasinormal modes of a real massive scalar field and we compare our results with those of other references.