The quantum structure of black holes

TL;DR

This paper reviews the quantum structure of black holes in string theory, focusing on microstates, entropy, Hawking radiation, and how quantum effects can manifest at macroscopic scales near the horizon.

Contribution

It provides an elementary overview of black hole microstates and introduces the concept of fractionation leading to observable quantum effects at horizon-scale distances.

Findings

Black hole entropy can be explained by string microstates.

Hawking radiation can be derived from these microstates.

Fractionation causes quantum effects to extend over macroscopic horizon scales.

Abstract

We give an elementary review of black holes in string theory. We discuss black hole entropy from string microstates and Hawking radiation from these states. We then review the structure of 2-charge microstates, and explore how `fractionation' can lead to quantum effects over macroscopic length scales of order the horizon radius.