Stability and Anti-evaporation of the Schwarzschild-de Sitter Black   Holes in Bigravity
  We study the stability under the perturbation and the related anti-evaporation of the Nariai space-time in bigravity. If we impose specific condition for the solutions and parameters, we obtain asymptotically de Sitter space-time, and show the existence of the Nariai space-time as a background solution. Considering the perturbation around the Nariai space-time up to first order, we investigate the behavior of black hole horizon. We show that the anti-evaporation does not occur on the classical level in the bigravity. 
Taishi Katsuragawa, Shin'ichi Nojiri
hep-th gr-qc