On black hole formation in higher dimensions

TL;DR

This paper investigates black hole formation mechanisms in higher dimensions, revealing that typical collapse and accretion processes are hindered unless in pure Lovelock gravity, which allows these processes to operate.

Contribution

It demonstrates that in higher dimensions, standard black hole formation processes are generally ineffective unless in pure Lovelock gravity, highlighting a unique aspect of higher-dimensional gravity theories.

Findings

Collapse and accretion processes are not attractive in higher dimensions with angular momentum.

Pure Lovelock gravity permits these processes to form black holes in higher dimensions.

Higher-dimensional black hole formation is restricted outside of pure Lovelock gravity.

Abstract

The two main processes of black hole formation are: one, collapse of a matter cloud under its own gravity and the other is accretion of matter onto an already existing gravitating centre. The necessary condition for both the processes to operate is that overall force on collapsing fluid element or on test accreting particles is attractive. It turns out that this is not the case in general in higher dimensions greater than the usual four for collapsing or accreting matter having non-zero angular momentum. Thus both these processes cannot operate in higher dimensions to form a rotating black hole. The only theory in which this is not the case in higher dimensions is the pure Lovelock gravity where both these processes could in principle work for formation of black holes.