New instability of non-extremal black holes: spitting out supertubes

TL;DR

This paper investigates the stability of non-extremal rotating black holes in five dimensions by analyzing supertube probes, revealing conditions under which stable bound states can form near extremality and connecting these to thermodynamic instabilities in the dual CFT.

Contribution

It demonstrates the existence of stable supertube-black hole bound states near extremality and links bulk instabilities to dual CFT phase transitions, extending previous supersymmetric results.

Findings

Stable bound states exist near extremality with lower energy than mergers.

Metastability of bound states disappears with increased non-extremality.

Thermodynamic instability in the CFT maps to tunneling instability in the bulk.

Abstract

We search for stable bound states of non-extremal rotating three-charge black holes in five dimensions (Cvetic-Youm black holes) and supertubes. We do this by studying the potential of supertube probes in the non-extremal black hole background and find that generically the marginally bound state of the supersymmetric limit becomes metastable and disappears with non-extremality (higher temperature). However near extremality there is a range of parameters allowing for stable bound states, which have lower energy than the supertube-black hole merger. Angular momentum is crucial for this effect. We use this setup in the D1-D5 decoupling limit to map a thermodynamic instability of the CFT (a new phase which is entropically dominant over the black hole phase) to a tunneling instability of the black hole towards the supertube-black hole bound state. This generalizes the results of ArXiv:1108.0411 [hep-th], which mapped an entropy enigma in the bulk to the dual CFT in a supersymmetric setup.