# Quantum-corrected black holes and naked singularities in (2+1)-dimensions

## TL;DR

This paper analytically studies how quantum effects from a conformally-coupled scalar field influence (2+1)-dimensional black holes and naked singularities, revealing horizon growth, singularity formation, and quantum censorship.

## Contribution

It provides the first analytical quantum-backreacted metrics for rotating (2+1)-dimensional black holes and naked singularities, demonstrating quantum effects as a cosmic censor.

## Key findings

- Quantum effects increase the event horizon and ergosphere size.
- Quantum corrections induce a curvature singularity at the Cauchy horizon.
- Quantum effects can turn naked singularities into black holes.

## Abstract

We analytically investigate the pertubative effects of a quantum conformally-coupled scalar field on rotating (2+1)-dimensional black holes and naked singularities. In both cases we obtain the quantum-backreacted metric analytically. In the black hole case, we explore the quantum corrections on different regions of relevance for a rotating black hole geometry. We find that the quantum effects lead to a growth of both the event horizon and the ergosphere, as well as to a reduction of the angular velocity compared to their corresponding unperturbed values. Quantum corrections also give rise to the formation of a curvature singularity at the Cauchy horizon and show no evidence of the appearance of a superradiant instability. In the naked singularity case, quantum effects lead to the formation of a horizon that hides the conical defect, thus turning it into a black hole. The fact that these effects occur not only for static but also for spinning geometries makes a strong case for the r\^ole of quantum mechanics as a cosmic censor in Nature.