Black hole state degeneracy in Loop Quantum Gravity
  The combinatorial problem of counting the black hole quantum states within the Isolated Horizon framework in Loop Quantum Gravity is analyzed. A qualitative understanding of the origin of the band structure shown by the degeneracy spectrum, which is responsible for the black hole entropy quantization, is reached. Even when motivated by simple considerations, this picture allows to obtain analytical expressions for the most relevant quantities associated to this effect. 
Ivan Agullo, Jacobo Diaz-Polo, Enrique Fernandez-Borja