Constituent Model of Extremal non-BPS Black Holes

TL;DR

This paper models extremal non-BPS black holes as bound states of BPS constituents, verifying stability and no-force conditions across duality frames, providing insights into their structure and stability.

Contribution

It introduces a constituent model for extremal non-BPS black holes, extending the understanding of their composition and stability across different duality frames.

Findings

No-force condition verified for constituents in probe approximation

Explicit constituent model for D0-D6 system provided

Stability of the constituent model demonstrated in weak coupling regime

Abstract

We interpret extremal non-BPS black holes in four dimensions as threshold bound states of four 1/2-BPS constituents. We verify the no-force condition for each of the primitive constituents in the probe approximation. Our computations are for a seed solution with $\bar{D0}-D4$ charges and equal $B$-fields, but symmetries extend the result to any U-dual frame. We make the constituent model for the $D0-D6$ system explicit, and also discuss a duality frame where the constituents are $D3$ branes at angles. We demonstrate stability of the constituent model in the weak coupling description of the constituent D-branes. We discuss the relation between the BPS and non-BPS branches of configuration space.