Scalar perturbations and strong cosmic censorship for an asymptotically de Sitter regular black hole
Abstract
We investigate the quasinormal modes (QNMs) of scalar perturbations and strong cosmic censorship (SCC) in regular Ayón-Beato-García-Bronnikov-de Sitter (ABGB-dS) black hole spacetime. The main motivation of this work is to clarify whether the regularization of black hole core, which removes the central singularity, can also change the fate of SCC connected to the Cauchy horizon. We first study the dependence of the scalar QNM frequency (QNF) on the scalar mass and black hole parameters. For angular number l=0, a small scalar mass can give rise to a slowly decaying mode which is purely imaginary, while it will become complex for large enough scalar mass and we call it dS-like mode. We also find that the black hole charge and cosmological constant affect the QNM spectrum in qualitatively opposite ways. We then examine SCC under massless and massive scalar perturbations. For massless perturbations, the QNMs spectrum can be organized into photon sphere (PS), de Sitter (dS) and near-extremal (NE) families. Compared with the SCC in the Reissner-Nordström-de Sitter (RN-dS) case, SCC is generally more easily violated in the ABGB-dS spacetime, although this tendency is reversed for sufficiently large cosmological constant. For massive scalar perturbations, we find that the scalar mass does not restore SCC. Instead, it can enhance the violation by driving the system into the regime β>1. At last, we discuss what we may expect from the violation of SCC in a regular black hole spacetime.
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BibTeX
@misc{liu2026scalar,
title = {{Scalar perturbations and strong cosmic censorship for an asymptotically de Sitter regular black hole}},
author = {Hang Liu and Hong Guo},
howpublished = {arXiv},
year = {2026},
month = oct,
doi = {10.48550/arxiv.2607.24119},
eprint = {2607.24119},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2607.24119},
}
RIS
TY - UNPB
TI - Scalar perturbations and strong cosmic censorship for an asymptotically de Sitter regular black hole
AU - Hang Liu
AU - Hong Guo
PY - 2026
DA - 2026/10/29
PB - arXiv
DO - 10.48550/arxiv.2607.24119
UR - https://arxiv.org/abs/2607.24119
AB - We investigate the quasinormal modes (QNMs) of scalar perturbations and strong cosmic censorship (SCC) in regular Ayón-Beato-García-Bronnikov-de Sitter (ABGB-dS) black hole spacetime. The main motivation of this work is to clarify whether the regularization of black hole core, which removes the central singularity, can also change the fate of SCC connected to the Cauchy horizon. We first study the dependence of the scalar QNM frequency (QNF) on the scalar mass and black hole parameters. For angular number l=0, a small scalar mass can give rise to a slowly decaying mode which is purely imaginary, while it will become complex for large enough scalar mass and we call it dS-like mode. We also find that the black hole charge and cosmological constant affect the QNM spectrum in qualitatively opposite ways. We then examine SCC under massless and massive scalar perturbations. For massless perturbations, the QNMs spectrum can be organized into photon sphere (PS), de Sitter (dS) and near-extremal (NE) families. Compared with the SCC in the Reissner-Nordström-de Sitter (RN-dS) case, SCC is generally more easily violated in the ABGB-dS spacetime, although this tendency is reversed for sufficiently large cosmological constant. For massive scalar perturbations, we find that the scalar mass does not restore SCC. Instead, it can enhance the violation by driving the system into the regime β>1. At last, we discuss what we may expect from the violation of SCC in a regular black hole spacetime.
ER -