  Regarding the spin-up of Schwarzschild-Kerr and Banados-Teitelboim-Zanelli
systems as a symmetry breaking phase transition, critical exponents are
evaluated and compared with classical Landau predictions. We suggest a
definition of isothermal compressibity which is independent of spin direction.
We find identical exponents for both systems, and possible universality in the
phase transitions of these systems.
