Test bodies and naked singularities: is the self-force the cosmic censor?

TL;DR

This paper investigates whether the conservative self-force can prevent the formation of naked singularities when spinning up black holes with test bodies, potentially supporting the Cosmic Censorship Conjecture.

Contribution

It demonstrates that for certain trajectories, the conservative self-force is significant and likely acts to prevent naked singularity formation, refining previous neglect of self-force effects.

Findings

Radiative effects can be neglected for some trajectories.

Conservative self-force has the potential to prevent naked singularities.

Supports the Cosmic Censorship Conjecture by showing self-force effects are protective.

Abstract

Jacobson and Sotiriou showed that rotating black holes could be spun-up past the extremal limit by the capture of non-spinning test bodies, if one neglects radiative and self-force effects. This would represent a violation of the Cosmic Censorship Conjecture in four-dimensional, asymptotically flat spacetimes. We show that for some of the trajectories giving rise to naked singularities, radiative effects can be neglected. However, for these orbits the conservative self-force is important, and seems to have the right sign to prevent the formation of naked singularities.