Conceptual Aspects of Gauge/Gravity Duality

TL;DR

This paper provides an introductory overview of gauge/gravity duality, highlighting its conceptual foundations, key examples like AdS/CFT, and potential extensions to other spacetimes and philosophical implications.

Contribution

It offers a comprehensive, conceptual review of gauge/gravity duality, including its origins, applications, and philosophical significance, aimed at broadening understanding of holography.

Findings

AdS/CFT correspondence as a central example

Applications to condensed matter, QCD, and hydrodynamics

Discussion of extensions to de Sitter spacetime and black holes

Abstract

We give an introductory review of gauge/gravity duality, and associated ideas of holography, emphasising the conceptual aspects. The opening Sections gather the ingredients, viz. anti-de Sitter spacetime, conformal field theory and string theory, that we need for presenting, in Section 5, the central and original example: Maldacena's AdS/CFT correspondence. Sections 6 and 7 develop the ideas of this example, also in applications to condensed matter systems, QCD, and hydrodynamics. Sections 8 and 9 discuss the possible extensions of holographic ideas to de Sitter spacetime and to black holes. Section 10 discusses the bearing of gauge/gravity duality on two philosophical topics: the equivalence of physical theories, and the idea that spacetime, or some features of it, are emergent.