Black Hole Thermodynamics from Euclidean Horizon Constraints
 

Steve Carlip
 
To explain black hole thermodynamics in quantum gravity, one must introduce constraints to ensure that a black hole is actually present.  I show that for a large class of black holes, the presence of such horizon constraints allows us to use conformal field theory techniques to compute the density of states, reproducing the Bekenstein-Hawking entropy in a nearly model-independent manner.  In particular, the method includes a standard AdS/CFT approach as a special case, and has interesting connections to a loop quantum gravity calculation as well, lending  some support to the claim of universality.