Third Quantization and Black Holes
  Recent results on the quantum mechanics of black holes indicate that the spacetime singularity can be avoided if the space of fields is extended in its domain as well as the vanishing of beta functions required as an equation in target space. Such an approach seems to inevitably lead to the quantization in this space that is the so-called third quantization. We discuss some of the implications of third quantization for the physics of blackholes in two dimensions. By discretizing the transverse dimensions describing the horizon it may also be possible to describe regulated four dimensional gravity in this manner and perhaps shed some light on the meaning of black hole entropy. 
Michael McGuigan