Decay channels for double extremal black holes in four dimensions

TL;DR

This paper investigates decay processes of charged, non-supersymmetric extremal black holes in string theory, identifying conditions for decay and stability, and revealing potential recombination into stable non-supersymmetric black holes.

Contribution

It demonstrates the existence of decay channels for double extremal black holes and identifies conditions under which stable non-supersymmetric black holes can form.

Findings

Decay channels exist at tree level for many double extremal black holes.

Some black holes are stable, indicating possible recombination into non-supersymmetric states.

Decay into BPS and anti-BPS constituents can be energetically favorable.

Abstract

We explore decay channels for charged black holes with vanishing temperature in $\mathcal{N}=2$ supersymmetric compactifications of string theory. If not protected by supersymmetry, such extremal black holes are expected to decay as a consequence of the weak gravity conjecture. We concentrate on double extremal, non-supersymmetric black holes for which the values of the scalar fields are constant throughout space-time, and explore decay channels for which decay into BPS and anti-BPS constituents is energetically favorable. We demonstrate the existence of decay channels at tree level for large families of double extremal black holes. For specific charges, we also find stable non-supersymmetric black holes, suggesting recombination of (anti)-supersymmetric constituents to a non-supersymmetric object.