Spectroscopy of a weakly isolated horizon
  The spectroscopy of a weakly isolated horizon (WIH) has been investigated. We obtain an equally spaced entropy spectrum with its quantum equal to the one given by Bekenstein [5]. We demonstrate that the quantization of entropy and area is a generic property of horizon, and the results exit in a wide class of spacetimes admitting weakly isolated horizons. Our results also indicate that the entropy quantum of the black hole horizon is closely related to Hawking temperature. 
Ge-Rui Chen and Yong-Chang Huang
gr-qc