Black Hole Entropy and Quantum Gravity

TL;DR

This paper introduces black hole entropy, reviews its theoretical foundations, compares approaches from string theory and canonical quantum gravity, and explores their commonalities, highlighting the ongoing quest to understand quantum aspects of black holes.

Contribution

It provides an elementary overview of black hole entropy, compares different quantum gravity approaches, and discusses their potential connections.

Findings

Comparison of Bekenstein and Hawking formulations

Discussion of microstate counting in string theory and canonical quantum gravity

Identification of common themes between different quantum gravity approaches

Abstract

An elementary introduction is given to the problem of black hole entropy as formulated by Bekenstein and Hawking. The information theoretic basis of Bekenstein's formulation is briefly reviewed and compared with Hawking's approach. The issue of calculating the entropy by actual counting of microstates is taken up next within two currently popular approaches to quantum gravity, viz., string theory and canonical quantum gravity. The treatment of the former assay is confined to a few remarks, mainly of a critical nature, while some of the computational techniques of the latter approach are elaborated. We conclude by trying to find commonalities between these two rather disparate directions of work.