Gravitational collapse in $(2+1)$-dimensional Eddington-inspired Born-Infeld gravity

TL;DR

This paper investigates how a modified gravity theory, Eddington-inspired Born-Infeld gravity, affects the outcome of dust collapse in 2+1 dimensions, potentially avoiding naked singularities unlike in general relativity.

Contribution

It demonstrates that EiBI gravity can prevent naked singularities in 2+1D dust collapse, contrasting with general relativity, and explores implications for cosmic censorship and cosmological singularity avoidance.

Findings

EiBI gravity can avoid naked singularities in certain parameter ranges.

In GR, dust collapse always results in naked singularities in 2+1D.

Singularity avoidance via bounce in EiBI cosmology is unstable.

Abstract

We study here the gravitational collapse of dust in $(2+1)$-dimensional spacetimes for the formation of black holes (BH) and naked singularities (NS) as final states in a modified theory of gravity, with vanishing cosmological constant. From the perspective of cosmic censorship, we investigate the collapse of a dust cloud in Eddington-inspired Born-Infeld gravity (EiBI) and compare the results with those of general relativity (GR). It turns out that, as opposed to the general relativistic situation, where the outcome of dust collapse in $(2+1)$ dimensions is always a naked singularity, the EiBI theory has a certain range of parameter values that avoid the naked singularity. This indicates that a $(3+1)$-dimensional generalization of these results could be useful and worth examining. Finally, using the results here, we show that the singularity avoidance through homogeneous bounce in cosmology in this modified gravity is not stable.