Superstring holography and integrability in AdS_5 x S^5

TL;DR

This paper explores the detailed quantum aspects of superstring theory in AdS_5 x S^5 and its dual gauge theory, introducing worldsheet interaction corrections to test the AdS/CFT correspondence beyond classical limits.

Contribution

It introduces worldsheet interaction corrections to the pp-wave string theory, providing new rigorous tests of the AdS/CFT duality in the quantum regime.

Findings

Successful incorporation of interaction corrections in string theory

Enhanced understanding of AdS/CFT correspondence at quantum level

Potential insights into strong coupling behavior of Yang-Mills theories

Abstract

The AdS/CFT correspondence provides a rich testing ground for many important topics in theoretical physics. The earliest and most striking example of the correspondence is the conjectured duality between the energy spectrum of type IIB superstring theory on AdS_5 x S^5 and the operator anomalous dimensions of N=4 supersymmetric Yang-Mills theory in four dimensions. While there is a substantial amount of evidence in support of this conjecture, direct tests have been elusive. The difficulty of quantizing superstring theory in a curved Ramond-Ramond background is compounded by the problem of computing anomalous dimensions for non-BPS operators in the strongly coupled regime of the gauge theory. The former problem can be circumvented to some extent by taking a Penrose limit of AdS_5 x S^5, reducing the background to that of a pp-wave (where the string theory is soluble). A corresponding limit of the gauge theory was discovered by Berenstein, Maldacena and Nastase, who obtained successful agreement between a class of operator dimensions in this limit and corresponding string energies in the Penrose limit. In this dissertation we present a body of work based largely on the introduction of worldsheet interaction corrections to the free pp-wave string theory by lifting the Penrose limit of AdS_5 x S^5. This provides a new class of rigorous tests of AdS/CFT that probe a truly quantum realm of the string theory. By studying the correspondence in greater detail, we stand to learn not only about how the duality is realized on a more microscopic level, but how Yang-Mills theories behave at strong coupling. The methods presented here will hopefully contribute to the realization of these important goals.