Hairy black holes and solitons in global AdS 5

TL;DR

This paper comprehensively analyzes hairy black holes and solitons in AdS5 with a charged scalar, revealing how their existence and properties depend on the scalar charge and phase transitions with Reissner-Nordstrom-AdS black holes.

Contribution

It provides a detailed classification of solutions in Einstein-Maxwell-scalar theory in AdS5, highlighting the dependence on scalar charge and the phase structure involving superradiant instabilities.

Findings

Hairy black holes exist at all charges for large scalar charge 'e'

Solitary solutions hit the Chandrashekhar limit at small 'e'

Hairy black holes merge with Reissner-Nordstrom-AdS black holes at a critical phase boundary

Abstract

We use a mix of analytic and numerical methods to exhaustively study a class of asymptotically global AdS solitons and hairy black hole solutions in negative cosmological constant Einstein Maxwell gravity coupled to a charged massless scalar field. Our results depend sensitively on the charge 'e' of the scalar field. The solitonic branch of solutions we study hit the Chandrashekhar limit at finite mass at small 'e', but extends to arbitrarily large mass at larger 'e'. At low values of 'e' no hairy black holes exist. At intermediate values of 'e' hairy black holes exist above a critical charge. At large 'e' hairy black holes exist at all values of the charge. The lowest mass hairy black holes is a smooth zero entropy soliton at small charge, but a (probably) singular nonzero entropy hairy black hole at larger charge. In a phase diagram of solutions, the hairy black holes merge with the familiar Reissner-Nordstrom-AdS black holes along a curve that is determined by the onset of the superradiant instability in the latter family.