Cosmic censorship for AdS5-Kerr

Abstract

We show that cosmic censorship takes an exceptionally complex and interesting form in the case of five-dimensional AdS-Kerr black holes, due to the unusually distant relation obtaining in that case between the black hole parameters and the physical mass and angular momentum. One finds that, in this case, censorship is less restrictive than one might hope: it apparently allows some rather bizarre behaviour, and in particular does not prohibit arbitrarily large angular momenta. We find however that most of the unwelcome geometries permitted by censorship can be eliminated by requiring stability against pairproduction of branes. We suggest that the small set of surviving problematic cases can be eliminated in a natural way by imposing a certain (holographic) bound on the physical mass.

Charged particle production rate from cosmic censorship in dilaton black hole spacetimes

“…One might take a step back and ask whether we need to worry about violation of the cosmic censorship, since singularities are likely to be "cured" in a fully working theory of quantum gravity [35,36], or otherwise prevented from ever arising since the black holes themselves could be de-stabilized by stringy effects [37]. Although it is almost always taken as granted that singularity will be resolved by quantum gravity, but since we do not yet have such a theory, we do not know for sure.…”

“…It should be emphasized that for GHS black holes, the extremal case is not a zero temperature state with nonzero entropy, such as an extremal RN black hole 3 . It is also not an extremal vanishing horizon (EVH) spacetime, such as a 5-dimensional extremal Kerr black hole with one angular parameter set to zero, which has both zero temperature and zero entropy (the horizon essentially coincides with the singularity) [37]. Instead, an extremal GHS black hole is a bizarre configuration that has zero size (with horizon coincides with a null singularity) but nonzero temperature 4 .…”

Event horizon wrinklification

“…The physical angular momentum J is also determined by the parameters M, a in the metric. For the exact expressions, see [18]. It will be useful to use a dimensionless version of M, defined as…”

“…We see that a near-extremal black hole of this kind has r H ≈ 0. Censorship for these black holes [12] excludes, for each value of μ, a finite range of values for A/L, extending below and above unity. The black holes corresponding to values above unity were called 'transunital' black holes 8 in [21], and these are the objects of interest to us here.…”

“…One obvious quantity to check is the specific heat of the black hole. In this case it is positive, see footnote 7 of [12]. Let us consider other potential instabilities 11 .…”