As far as I understand, the AdS/CFT correspondence proposed by Maldacena is an exact duality to a four-dimensional theory, which interpolates between one well-defined conformal field theory in the UV and another conformal field theory in the IR. So holographic renormalization is in one-to-one correspondence with renormalization in the four-dimensional theory. Or, in simpler terms, according to this theory, dynamical phenomena occurring in a curved space-time like black holes can be described by a theory on a flat space-time, just as a hologram can record the information of 3D objects on a plane
The web is full of popular science articles about this correspondence, but the only "detailed" results that I found about Maldacena's theory is that it has been sucessfully tested by calculating the relationship between the mass and the temperature of a black hole on a computer.
My specific question is: has anybody calculated the predictions of holographic theory at a point that corresponds to the center of a black hole (singularity?) in the 4D theory, and if not, why? If yes were could I find more details? Thanks!