Year: 2026
Type: article
Abstract: We revisit quasinormal modes of Reissner-Nordström-de Sitter black holes, a classical and seemingly well-understood solution of Einstein-Maxwell theory with a positive cosmological constant. While previous studies have focused almost exclusively on the oscillatory photon-sphere branch, we show that two additional branches of nonoscillatory, purely imaginary modes - associated with the de Sitter horizon and with the regime of near-extremal charge (zero-damped) - are essential for a complete description of the spectrum. These modes have so far remained largely unexplored for gravitational perturbations despite their relevance for late-time dynamics and stability. In particular, we derive accurate analytic expressions for the purely imaginary quasinormal frequencies in the slow-damping regime, providing a complete description of this sector of the spectrum.
DOI: 10.1103/rmkq-fz1t
Authors: Z. Stuchlík, A. Zhidenko
Institutions: Silesian University in Opava, Universidade Federal do ABC
Language: English
Subfield: Nuclear and High Energy Physics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W4417308695