Microstate Geometries and Entropy Enhancement

TL;DR

This paper reviews recent progress in constructing smooth, horizonless microstate geometries in string theory that mimic black holes and discusses their physical implications.

Contribution

It summarizes advances in creating horizonless geometries that replicate black holes, highlighting their structure and significance in understanding black-hole microstates.

Findings

Construction of smooth microstate geometries

Microstate geometries mimic black holes from infinity to horizon

Implications for black-hole entropy and information

Abstract

In string theory, black-hole backgrounds are far from unique and there are large families of completely smooth, horizonless geometries with the same structure as a black hole from infinity down to the neighborhood of the black-hole horizon. These microstate geometries cap off in foam of topological bubbles. I review some of the recent progress in constructing these smooth horizonless geometries and discuss some of the physical implications.