Quantum general relativity and Hawking radiation
  In a previous paper we have set up the Wheeler-DeWitt equation which describes the quantum general relativistic collapse of a spherical dust cloud. In the present paper we specialize this equation to the case of matter perturbations around a black hole, and show that in the WKB approximation, the wave-functional describes an eternal black hole in equilibrium with a thermal bath at Hawking temperature. 
Cenalo Vaz, Claus Kiefer, T.P. Singh and Louis Witten