Black holes on the brane

TL;DR

This paper presents exact solutions for static black holes on a brane in five-dimensional gravity, revealing a tidal charge effect that modifies black hole properties in the Randall-Sundrum scenario.

Contribution

It demonstrates that the Reissner-Nordstrom metric can be reinterpreted as a black hole without electric charge but with a tidal charge from extra-dimensional gravity, providing new insights into brane-world black holes.

Findings

Tidal charge can be negative, altering horizon structure.

The solution satisfies a closed system of equations on the brane.

Significant tidal effects may occur in strong gravity or primordial black holes.

Abstract

We consider exact solutions for static black holes localized on a three-brane in five-dimensional gravity in the Randall-Sundrum scenario. We show that the Reissner-Nordstrom metric is an exact solution of the effective Einstein equations on the brane, re-interpreted as a black hole without electric charge, but with instead a tidal 'charge' arising via gravitational effects from the fifth dimension. The tidal correction to the Schwarzschild potential is negative, which is impossible in general relativity, and in this case only one horizon is admitted, located outside the Schwarzschild horizon. The solution satisfies a closed system of equations on the brane, and describes the strong-gravity regime. Current observations do not strongly constrain the tidal charge, and significant tidal corrections could in principle arise in the strong-gravity regime and for primordial black holes.