Strong cosmic censorship for the massless charged scalar field in the Reissner-Nordstrom-de Sitter spacetime

TL;DR

This paper investigates the validity of strong cosmic censorship in Reissner-Nordstrom-de Sitter black holes by analyzing the quasi-normal modes of a massless charged scalar field, finding that censorship is generally upheld except near extremality.

Contribution

It extends previous studies by numerically calculating quasi-normal modes for a charged scalar field, showing how charge affects the violation of cosmic censorship.

Findings

Strong cosmic censorship is generally recovered for charged scalar fields.

Violation persists near the extremal charge limit $Q ightarrow Q_m$ when the scalar field is appropriately charged.

Numerical analysis confirms the role of charge in the stability of the Cauchy horizon.

Abstract

It has recently been shown that the strong cosmic censorship conjecture can be violated by the massless neutral scalar field in the nearly extremal Reissner-Nordstrom-de Sitter black hole. However, the formation of such a black hole by gravitational collapse necessitates the presence of the charged sector on top of the Einstein-Maxwell system. Thus we numerically calculate the quasi-normal modes for a massless charged scalar field in the Reissner-Nordstrom-de Sitter spacetime by generalizing the characteristic formulation to the charged case. As a result, the strong cosmic censorship turns out to be recovered by our massless charged scalar field except in the highly extremal limit $Q\rightarrow Q_m$, where the violation still occurs when the scalar field is appropriately charged.