Weak cosmic censorship conjecture in Kerr-Newman-(anti-)de Sitter black hole with charged scalar field

Bogeun Gwak

doi:10.1088/1475-7516/2021/10/012

Abstract

We investigate the weak cosmic censorship conjecture in extremal and near-extremal Kerr-Newman-(anti-)de Sitter black holes by the scattering of a massive scalar field with an electric charge. Under this scattering, the scalar field fluxes change the black hole state, as determined by the mass, angular momentum, and electric charge. The black hole may exceed its extremal condition because of these changes. However, we find that the black hole cannot be overcharged or overspun by the scattering. In particular, although the fluxes are closely associated with the asymptotic boundary conditions along the flat, anti-de Sitter, and de Sitter spacetimes, the weak cosmic censorship conjecture is valid for any scalar field boundary conditions. Moreover, the validity of the weak cosmic censorship conjecture is thermodynamically preferred for this scattering.

Highlights

Black holes were theoretically predicted in general relativity as the end states of collapsing massive stars [1]
We investigated the weak cosmic censorship (WCC) conjecture for the KN(A)de Sitter (dS) black hole with an arbitrary cosmological constant Λ
Based on our study of the KN(A)dS black hole, we can arrive at the generalized conclusion that the WCC conjecture is valid for black holes

Summary

Introduction

Black holes were theoretically predicted in general relativity as the end states of collapsing massive stars [1]. As regards the Hawking temperature, the zero-temperature state or extremal black hole is not reached through such finite operations [65] These findings imply that the classical tests of the WCC conjecture are closely associated with the related quantum physics through the laws of thermodynamics. For a nonzero cosmological constant, the angular velocity is nonzero at the asymptotic limit, which implies that the asymptotic observer is not static This causes difficulties in defining conserved quantities in such spacetimes and affects the thermodynamics and WCC conjecture [29,108]. This problem can be resolved through coordinate transformations to recover an asymptotically static observer with zero angular velocity [110]. These are significant for a Nariai black hole and we discuss them

Solution to Scalar Field Equation

Scalar Field Fluxes

Kerr-Type Near-Extremal KN-AdS and KN-dS Black Holes

Nariai-Type Near-Extremal KN-dS Black Holes

Laws of Thermodynamics

Summary