# Black holes as bubbles of AdS

## TL;DR

This paper introduces stable, horizonless bubbles of Anti-de Sitter space within Minkowski spacetime as an alternative endpoint of gravitational collapse, with properties similar to black holes and a string theory realization.

## Contribution

It proposes a novel stable bubble model of AdS within Minkowski space, supported by string theory constructions, offering new insights into black hole entropy and stability.

## Key findings

- Bubbles are horizonless and up to 12.5% larger than Schwarzschild radius.
- Bubbles are stable against small perturbations.
- The model provides a new perspective on extremal Reissner-Nordström black hole entropy.

## Abstract

In this paper we propose that bubbles of AdS within Minkowski spacetime, stabilized at a finite radius by stiff matter and an electromagnetic gas, can be an alternative endpoint of gravitational collapse. The bubbles are horizonless with a size up to 12.5% larger than their Schwarzschild radius depending on their charge. We argue that they are stable against small perturbations, and have thermodynamical properties similar to those of real black holes. We provide a realization of the bubbles within string theory that relies on a specific brane intersection giving rise to a shell carrying dissolved charges from lower dimensional D-branes as well as a gas of open strings. We also note that our construction provides a new way of understanding the entropy of Reissner-Nordstr\"om black holes in the extremal limit.