Quasinormal modes of d-dimensional spherical black holes with a near extreme cosmological constant
C. Molina
TL;DR
This work analyzes scalar perturbations outside near-extremal horizons of $d$-dimensional Schwarzschild-de Sitter and Reissner-Nordström-de Sitter black holes. In the near-extreme limit, the effective radial potential becomes the solvable Pöschl-Teller form, yielding analytic quasinormal mode frequencies that are largely independent of spacetime dimensionality and scalar mass. The authors generalize previous four-dimensional results to higher dimensions and charged cases, providing explicit expressions for the QNM frequencies in terms of the metrics’ parameters $m$, $q$, and $\Lambda$, and showing a universal relaxation pattern. These results have implications for gravitational wave phenomenology in non-asymptotically flat spacetimes and for understanding the geometric influence on field decay near extremality.
Abstract
We derive an expression for the quasinormal modes of scalar perturbations in near extreme d-dimensional Schwarzschild-de Sitter and Reissner-Nordstrom-de Sitter black holes. We show that, in the near extreme limit, the dynamics of the scalar field is characterized by a Poschl-Teller effective potential. The results are qualitatively independent of the spacetime dimension and field mass.