Maxwell's demon and information channel width of a black hole
  Using a new generalized second law of thermodynamics, the information and entropy of a black hole and its accretion disk are analyzed respectively. We find the bound of the information channel width of a black hole, which is determined by the variation rate of the horizon temperature and the mass of the black hole's shell(the accretion disk close to the horizon). 
Liangsuo Shu, Xiaokang Liu, Shiping Jin and Suyi Huang
quant-ph cs.IT math.IT