Extremal Vanishing Horizon Kerr-AdS Black Holes at Ultraspinning Limit

TL;DR

This paper constructs new extremal vanishing horizon black holes in odd dimensions using ultraspinning limits, explores their near horizon geometries with AdS3 throats, and confirms their thermodynamic and holographic properties.

Contribution

It introduces a novel class of EVH black holes via ultraspinning limits and analyzes their geometric, thermodynamic, and holographic characteristics.

Findings

EVH limit commutes with ultraspinning limit in Kerr-AdS black holes.

Near horizon geometries contain AdS3 throats, with BTZ black holes in near EVH cases.

Thermodynamics and entropy match between black holes and dual CFT.

Abstract

By utilizing the ultraspinning limit we generate a new class of extremal vanishing horizon (EVH) black holes in odd dimensions ($d\geq5$). Starting from the general multi-spinning Kerr-AdS metrics, we show the EVH limit commutes with the ultraspinning limit, in which the resulting solutions possess a non-compact but finite area manifold for all $(t,r\neq r_+)=const.$ slices. We also demonstrate the near horizon geometries of obtained ultraspinning EVH solutions contain an AdS$_3$ throats, where it would be a BTZ black hole in the near EVH cases. The commutativity of the ultraspinning and near horizon limits for EVH solutions is confirmed as well. Furthermore, we discuss only the five-dimensional case near the EVH point can be viewed as a super-entropic black hole. We also show that the thermodynamics of the obtained solutions agree with the BTZ black hole. Moreover we investigate the EVH/CFT proposal, demonstrating the entropy of $2$d dual CFT and Bekenstein-Hawking entropy are equivalent.