Independent of these constructions, the scattering probabilities of probes around the near-extremal
Kerr–Newman black hole can be reproduced near the superradiant bound by manipulating near-chiral
thermal two-point functions of a two-dimensional CFT. The result extends straightforwardly to
other asymptotically-flat or AdS black holes in various gravity theories. Finally away from
extremality, hidden symmetries are present in some scalar probes around
the Kerr–Newman black hole close enough to the horizon. We showed that several CFTs are
required to account for the entire probe dynamics in the near region in the regime of small mass,
small energy and small charge. This analysis does not extend straightforwardly to AdS black
holes.
These results – obtained in gravity coupled to matter – are naturally accounted for by assuming that the
microstates of asymptotically-flat black holes, at extremality and away from extremality, can be described
by CFTs and that the microstates of asymptotically-AdS black holes at extremality can be described
by chiral halves of
CFTs. Scattering amplitudes and hidden symmetries are also accounted
for by assuming that part of the dynamics of black holes can be mapped to the dynamics of
these CFTs once they are suitably coupled to the exterior black-hole region. By consistency
with the gravitational analysis, several CFT descriptions are available when several compact
symmetries are present. The existence of such CFTs is conjectural and only future
research will tell how far these Kerr/CFT correspondences and their extensions can be made more
precise.
A fair concluding remark would be that our understanding of the Kerr, Reissner–Nordström and Kerr–Newman black hole has increased over the last four years, but there is still a long road ahead of us to comprehend what these CFTs really are and what they are telling us about the nature of quantum black holes.
http://www.livingreviews.org/lrr-2012-11 |
Living Rev. Relativity 15, (2012), 11
![]() This work is licensed under a Creative Commons License. E-mail us: |