A black hole instability in five dimensions?

TL;DR

This paper investigates the dynamics of supertubes near rotating D1-D5-P black holes, revealing potential instabilities and suggesting that mergers could lead to new black object configurations beyond known solutions.

Contribution

It extends static analyses by including magnetic forces in moduli-space scattering, showing that supertubes can merge with black holes at higher angular momentum, indicating possible instabilities.

Findings

Supertubes can reach the horizon and merge with black holes at larger angular momentum.

Merger outcomes cannot be explained by known black objects, implying new instabilities.

Potential bifurcation into novel black object configurations is suggested.

Abstract

We study the moduli-space scattering of a two-charge supertube in the background of a rotating BPS D1-D5-P black hole in 4+1 dimensions, extending the static analysis of Bena and Kraus (hep-th/0402144). While the magnetic forces associated with this motion change the details considerably, the final conclusion is similar to that of the static analysis: we find that one can bring the supertube to the horizon, so that the BMPV black hole and the supertube merge. However, our analysis shows that this can occur even at significantly larger values of the angular momentum than was indicated by the static analysis. For a range of parameters, conservation laws and the area theorem forbid the result of the merger from being any single known object: neither near-extremal black holes nor non-supersymmetric black rings are allowed. Such results suggest that the merger triggers an instability of the rotating D1-D5-P black hole, perhaps leading to bifurcation into a pair of black objects.