Quantum Black Hole Thermodynamics

Abstract

Black hole thermodynamics is reviewed for non-experts, underlining the need to go beyond classical general relativity. The origin of the microcanonical entropy of isolated, non-radiant, non-rotating black holes is traced, within an approach to quantum spacetime geometry known as Loop Quantum Gravity, to the degeneracy of boundary states of an SU(2) Cherns Simons theory. Not only does one retrieve the area law for black hole entropy, an infinite series of finite and unambiguous corrections to the area law are derived in the limit of large horizon area. The inclusion of black hole radiance is shown to lead to additional effects related to the thermal stability of black holes. A universal criterion for such stability is derived, in terms of the mass and the microcanonical entropy discussed earlier. As a byproduct, a universal form for the canonical entropy of black holes is obtained, in terms of the better-understood microcanonical entropy.