Entropy of Neutrino Field in Kerr-Newman-de Sitter Space-time

By using the improved brick wall model, we regard the two null horizons in Kerr-Newman-de Sitter space-time as two independent thermal equilibrium systems and we calculate the entropies of both horizons due to neutrino field. We propose that the so-called “ superradiant” modes cannot be considered because fermion fields does not display supperradiance. In fact, the nonsuperradiant part does exactly show the expected area-law entropy. Moreover, our cut-off ε, which does not require an angular cut-off, is independent of angle θ.