Fragmentation of AdS$_5$-Kerr Black Holes

Abstract

Recent work has raised the exciting prospect that violations of the Kerr bound may be observable by the Event Horizon Telescope or the gravitational wave mission LISA. Furthermore, it has recently been suggested that some primordial black holes might have rapidly growing specific angular momenta. On the other hand, certain Quark-Gluon Plasmas, whose physics is often studied using techniques from black hole theory, have recently been observed to have very large vorticities. These observations prompt a question: is there a systematic way of understanding black holes with extremely high specific angular momenta? Holography suggests a way of attacking this problem. The basic idea is simple: whether or not Censorship is violated in physical spacetime, perhaps it is always respected in the dual bulk spacetime. When AdS 5 Censorship holds, the specific angular momenta of the bulk black hole is strongly restricted, not by Censorship itself but by requiring stability against various effects such Emparan-Myers fragmentation. Consequently the specific angular momentum of the boundary system, which may be a field theory modelling the Quark-Gluon Plasma, or perhaps a primordial black hole, is constrained. We study such constraints and their implications in these two examples.

Null Hypersurface Caustics, Closed Null Curves, and Super-Entropy

“…The metric of the Kerr-AdS 5 spacetime with a single rotation axes in 5 dimensions 2 is [9][10][11][12]:…”

“…Following [11], we refer to those black holes with a > L as "transunital", while those with a < L as "cisunital". There exists a mapping [14,15] between the metrics of transunital and cisunital black holes, such that the geometries are locally equivalent.…”

Event Horizon Wrinklification

“…Censorship for these black holes [11] 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 in [15], and these are the objects of interest to us here. In detail, the condition for Censorship to hold is that A/L must satisfy either…”

“…In [15] the ratio of the two entropies was computed for transunital black holes. Evaluating it at the parameter values given in (13), we have…”

“…Below the blue curve, one has black holes unstable against fragmentation (the subscript "0" for a 0 and M 0 indicates, in this context, the initial configuration of the black hole -if thermodynamically unstable it will transit into another configuration. See [15] for detail).…”