Introduction to Gauge/Gravity Duality

TL;DR

Polchinski surveys gauge/gravity duality with AdS5×S5 as the canonical example, detailing how a four-dimensional N=4 SYM theory is dual to type IIB string theory on AdS5×S5. He outlines the gravity and field theory perspectives, the GKPW dictionary, and how bulk fields map to boundary operators and their correlators, while emphasizing the roles of large N and strong coupling. The lectures then explore mechanisms to break conformal symmetry and construct richer holographic duals via Coulomb branches, RG flows, orbifolds, and various brane configurations, including nonconformal branes and intersecting branes. The overarching message is that holography provides a nonperturbative framework connecting strongly coupled gauge theories to higher-dimensional gravity, with broad implications for quantum gravity and strongly correlated systems.

Abstract

These lectures are an introduction to gauge/gravity duality, presented at TASI 2010. The first three sections present the basics, focusing on $AdS_5 \times S^5$. The last section surveys a variety of ways to generate duals of reduced symmetry.