Almost BPS black holes

TL;DR

This paper introduces a new class of non-BPS black hole solutions called 'almost BPS' in supergravity, which are locally supersymmetric and can have complex structures like multiple centers and nontrivial moduli.

Contribution

The authors identify and analyze 'almost BPS' solutions in five-dimensional supergravity, extending to four dimensions via dimensional reduction, with explicit examples.

Findings

'Almost BPS' solutions are supersymmetric on local patches.

These solutions can have multiple centers and complex asymptotic moduli.

Explicit single and two-center solutions are constructed.

Abstract

We study non-BPS black hole solutions to ungauged supergravity with 8 supercharges coupled to vector multiplets in four and five dimensions. We identify a large class of five dimensional non-BPS solutions, which we call "almost BPS", that are supersymmetric on local patches and satisfy a first order flow governed by harmonic functions. By dimensional reduction, they give rise to new non-BPS solutions in four dimensions. These solutions allow for some nontrivial asymptotic moduli and multiple centres, similar to their globally supersymmetric cousins. We explicitly discuss a single centre and a two centre example.