A boundary value problem for the five-dimensional stationary rotating   black holes
  We study the boundary value problem for the stationary rotating black hole solutions to the five-dimensional vacuum Einstein equation. Assuming the two commuting rotational symmetry and the sphericity of the horizon topology, we show that the black hole is uniquely characterized by the mass, and a pair of the angular momenta. 
Yoshiyuki Morisawa and Daisuke Ida