Lectures on black holes and the AdS_3 / CFT_2 correspondence
  We present a detailed discussion of AdS_3 black holes and their connection to two-dimensional conformal field theories via the AdS/CFT correspondence. Our emphasis is on deriving refined versions of black hole partition functions, that include the effect of higher derivative terms in the spacetime action as well as non-perturbative effects. We include background material on gravity in AdS_3, in the context of holographic renormalization. 
Per Kraus