What Exactly is the Information Paradox?

TL;DR

This paper reviews the black hole information paradox, explaining its origins, the assumptions behind it, and how string theory's quantum effects suggest a resolution through the fuzzball concept.

Contribution

It provides a pedagogical overview of the paradox, reformulates Hawking's argument as a theorem, and discusses how string theory's quantum effects challenge the traditional assumptions.

Findings

Hawking's argument can be viewed as a theorem under certain assumptions.

String theory's quantum effects violate the assumptions leading to the paradox.

Fuzzballs offer a potential resolution to the information paradox.

Abstract

The black hole information paradox tells us something important about the way quantum mechanics and gravity fit together. In these lectures I try to give a pedagogical review of the essential physics leading to the paradox, using mostly pictures. Hawking's argument is recast as a `theorem': if quantum gravity effects are confined to within a given length scale and the vacuum is assumed to be unique, then there will be information loss. We conclude with a brief summary of how quantum effects in string theory violate the first condition and make the interior of the hole a `fuzzball'.