Quantization of the universe as a black hole
  It has been shown that black holes can be quantized by using Bohr's idea of quantizing the motion of an electron inside the atom. We apply these ideas to the universe as a whole. This approach reinforces the suggestion that it may be a way to unify gravity with quantum theory. 
M\`arius Josep Fullana i Alfonso and Antonio Alfonso-Faus
physics.gen-ph