On Special Re-quantization of a Black Hole
  Quantized expressions for the gravitational energy and momentum are derived from a linearized theory of teleparallel gravity. The derivation relies on a second-quantization procedure that constructs annihilation and creation operators for the graviton. The resulting gravitational field is a collection of gravitons, each of which has precise energy and momentum. On the basis of the weak-field approximation of Schwarzschild's solution, a new form for the quantization of the mass of a black hole is derived. 
S.C. Ulhoa
gr-qc