Introduction to branes and M-theory for relativists and cosmologists

TL;DR

This paper reviews superstring theories, introduces D-branes and M-theory, and explores their implications for black hole physics, dualities, and entropy calculations, connecting string theory concepts with cosmological and relativistic frameworks.

Contribution

It provides a comprehensive overview of superstring theories, D-branes, M-theory, and their applications to black hole entropy and dualities, highlighting recent developments for relativists and cosmologists.

Findings

D-branes imply an 11-dimensional M-theory framework.

Black hole entropy can be explained via string dualities and AdS/CFT.

Greybody factors for BTZ black holes are analyzed using string theory concepts.

Abstract

We review the recent developments in superstrings. We start with a brief summary of various consistent superstring theories and discuss T-duality which necessarily leads to the presence of D-branes. The properties of D-branes are summarized and we discuss how these suggest the existence of 11-dimensional quantum theory, M-theory, which is believed to give rise to various superstrings as perturbative expansions around particular backgrounds in the theory. We also discuss the interpretation of brane solutions as black holes in string theories and statistical explanation of Bekenstein-Hawking entropy. The idea behind this interpretation is that there is a fundamental duality between closed (gravity) and open (gauge theory) string degrees of freedom, one of whose manifestation is what is kown as AdS/CFT correspondence. The idea is used to discuss the greybody factors for BTZ black holes. Finally the entropy of various balck holes are discussed in connection with Cardy-Verlinde formula.