Remarks on Noether charges and black holes entropy
  We criticize and generalize some properties of Noether charges presented in a paper by V. Iyer and R. M. Wald and their application to entropy of black holes. The first law of black holes thermodynamics is proven for any gauge-natural field theory. As an application charged Kerr-Newman solutions are considered. As a further example we consider a (1+2) black hole solution. 
Lorenzo Fatibene, Marco Ferraris, Mauro Francaviglia, Marco Raiteri