Analytic solutions in the acoustic black hole analogue of the conical   Kerr metric
  We study the sound perturbation of a rotating acoustic black hole in the presence of a disclination. The radial part of the massless Klein-Gordon equation is written into a Heun form, and its analytical solution is obtained. These solutions have an explicit dependence on the parameter of the disclination. We obtain the exact Hawking-Unruh radiation spectrum. 
H. S. Vieira
gr-qc cond-mat.other