String Theory and Black Holes

TL;DR

This thesis provides a detailed microscopic understanding of Hawking radiation from D1/D5 black holes, establishing a correspondence between supergravity moduli and SCFT operators, and reconciling D-brane and semiclassical calculations.

Contribution

It constructs all short multiplets of the ${\cal N}=(4,4)$ SCFT on the symmetric product and links supergravity moduli to SCFT operators, clarifying the microscopic origin of Hawking radiation.

Findings

Explicit construction of SCFT short multiplets.

Matching of supergravity moduli with SCFT operators.

Absorption cross-section independent of moduli.

Abstract

This thesis aims to make precise the microscopic understanding of Hawking radiation from the D1/D5 black hole. We present an explict construction of all the shortmultiplets of the ${\cal N}=(4,4)$ SCFT on the symmetric product $\tilde{T}^4/S(Q_1Q_5)$. An investigation of the symmerties of this SCFT enables us to make a one-to-one correspondence beween the supergravity moduli and the marginal opeerators of the SCFT. We analyse the gauge theory dynamics of the splitting of the D1/D5 system into subsystems and show that it agrees with supergravity. We have shown that the fixed scalars of the D1/D5 system couple only to (2,2) operators thus removing earlier discrepancies between D-brane calculations and semiclassical calculations. The absorption cross-section of the minimal scalars is determined from first principles upto a propotionality constant. We show that the absorption cross-section of the minimal scalars computed in supergravity and the SCFT is independent of the moduli.