Sebastian Harris (DESY)

Abstract: AdS/CFT is a strong–weak duality: it allows the study of strongly coupled gauge theories through classical geometry, and highly stringy regimes of quantum gravity through perturbative gauge theory. This complementarity makes the correspondence powerful but also difficult to prove, since there is usually no regime in which both sides are simultaneously under computational control. AdS3 offers a remarkable exception to this. There exists an exactly solvable AdS3 string background dual to a free 2d gauge theory. In this context, AdS/CFT can be fully derived: It was shown that all closed string scattering amplitudes match precisely the local correlation functions of the dual gauge theory. The talk reviews this remarkable derivation and presents recent progress extending it to encompass branes and open strings, as well as the dual interfaces and their local excitations.