The Fate of a Five-Dimensional Rotating Black Hole via Hawking Radiation
  We study the evolution of a five-dimensional rotating black hole emitting scalar field radiation via the Hawking process for arbitrary initial values of the two rotation parameters $a$ and $b$. It is found that any such black hole whose initial rotation parameters are both nonzero evolves toward an asymptotic state   $a/M^{1/2}=b/M^{1/2}={\rm const}(\neq 0)$, where this constant is independent of the initial values of $a$ and $b$. 
Hidefumi Nomura, Shijun Yoshida, Makoto Tanabe, Kei-ichi Maeda