Ultraspinning limits and rotating hyperboloid membranes

TL;DR

This paper introduces a new class of rotating black holes with maximal rotation parameters in AdS space, exploring their thermodynamics and potential holographic applications.

Contribution

It applies the hyperboloid membrane limit to Kerr-AdS metrics to construct novel rotating black holes with maximal rotation parameters.

Findings

New rotating black hole solutions with maximal rotation in AdS.

Violation of the entropy/area law despite absence of Misner strings.

Potential relevance for holographic fluids with vorticity.

Abstract

We apply the hyperboloid membrane limit to the general Kerr-AdS metrics and their recently studied super-entropic cousins and obtain a new class of rotating black holes, for which the rotational parameters in multiple directions attain their maximal value---equal to the AdS radius. These new solutions have a potential application in the description of holographic fluids with vorticity. They also possess interesting thermodynamic properties: we show that---despite the absence of Misner strings---the Bekenstein--Hawking entropy/area law is still violated, raising a question about the origin of this violation.