Abstract
It is shown that the equations governing linearized gravitational (or
electromagnetic) perturbations of the near-horizon geometry of any known
extreme vacuum black hole (allowing for a cosmological constant) can be
Kaluza-Klein reduced to give the equation of motion of a charged scalar field
in AdS\_2 with an electric field. One can define an effective
Breitenlohner-Freedman bound for such a field. We conjecture that if a
perturbation preserves certain symmetries then a violation of this bound should
imply an instability of the full black hole solution. Evidence in favour of
this conjecture is provided by the extreme Kerr solution and extreme
cohomogeneity-1 Myers-Perry solution. In the latter case, we predict an
instability in seven or more dimensions and, in 5d, we present results for
operator conformal weights assuming the existence of a CFT dual. We sketch a
proof of our conjecture for scalar field perturbations.
Users
Please
log in to take part in the discussion (add own reviews or comments).