Dragging of inertial frames in the composed black-hole-particle system and the weak cosmic censorship conjecture

Shahar Hod

doi:10.1140/epjc/s10052-020-8285-z

Abstract

We analyze a gedanken experiment in which a spinning particle that also possesses an extrinsic orbital angular momentum is captured by a spinning Kerr black hole. The gravitational spin-orbit interaction decreases the energy of the particle, thus allowing one to test the validity of the Penrose weak cosmic censorship conjecture in extreme situations that have not been analyzed thus far. It is explicitly shown that, to leading order in the black-hole-particle interactions, the linearized test particle can over-spin the black hole, thus exposing its inner spacetime singularity to external observers. However, we prove that the general relativistic effect of dragging of inertial frames by the orbiting particle contributes to the energy budget of the system a non-linear black-hole-particle interaction term that ultimately ensures the validity of the Penrose cosmic censorship conjecture in this type of gedanken experiments.

Highlights

Singularities in curved spacetimes represent extreme physical situations in which general relativity, Einstein’s theory of gravity, loses its predictive power
In order to preserve the deterministic nature of classical general relativity in the presence of spacetime singularities, Penrose [1] has suggested that spacetime singularities that arise in gravitational collapse are always hidden inside of black holes
Physical processes that threat to remove the shieling horizon of a black hole and to expose its inner spacetime singularity to external observers are forbidden by the Penrose weak cosmic censorship conjecture [1]

Summary

Introduction

Singularities in curved spacetimes represent extreme physical situations in which general relativity, Einstein’s theory of gravity, loses its predictive power. In order to preserve the deterministic nature of classical general relativity in the presence of spacetime singularities, Penrose [1] has suggested that spacetime singularities that arise in gravitational collapse are always hidden inside of black holes This intriguing idea, known as the weak cosmic censorship conjecture, has attracted the attention of physicists and mathematicians over the last five decades (see e.g., [2,3,4,5,6,7,8,9,10,11,12,13,14] and references therein). Below we shall explicitly show that this intriguing general relativistic effect ensures the validity of the Penrose weak cosmic censorship conjecture [1] in the composed black-hole-particle gedanken experiment

Description of the composed black-hole-particle system

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