The asymptotic symmetries of three-dimensional AdS spaces with Brown-Henneaux boundary conditions have played a significant role in the discovery and subsequent developments of the AdS/CFT correspondence (or gauge/gravity duality), in particular in relation with the black hole entropy problem.
In this talk, we will describe instances of dualities where the background and boundary conditions depart from the usual AdS$_3$ ones, leading to new classes of holographic field theories with infinite-dimensional symmetries. We will discuss the implications of these symmetries, and contrast them with those of more familiar 2d CFTs, in the framework of near-extremal black holes and nearly-AdS$_2$ holography.
