Extremal vanishing horizon Kerr-AdS black holes at ultraspinning limit

Abstract

By utilizing the ultraspinning limit we generate a new class of extremal vanishing horizon (EVH) black holes in odd dimensions (d ≥ 5). 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 = 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 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 2d dual CFT and Bekenstein-Hawking entropy are equivalent.

Thermodynamic instabilities of generalized exotic BTZ black holes

“…When the equality is saturated, a black hole of a given thermodynamic volues has attained its maximal possible entropy. Since then, the isoperimetric ratio R of various black hole families have been studied, and some were found to violate this inequality [8][9][10][11][12][13][14][15][16]. Such black holes have come to be called super-entropic, since they have more entropy that the relation (1) would admit.…”

Ultra-spinning Chow’s black holes in six-dimensional gauged supergravity and their properties

“…Thus, it provides the first counter-example to this inequality, and such a black hole is dubbed as "superentropic". Up to date, a lot of new ultra-spinning black hole solutions [24][25][26][27][28][29][30] have been obtained from the known common rotating AdS black holes. In addition, various aspects of the ultra-spinning black holes, including thermodynamical properties [19,24,[26][27][28][31][32][33][34], horizon geometry [20,24,26], Kerr/CFT correspondence [25][26][27], geodesic motion [35] and null hypersurface caustics [36][37][38], etc., have been widely explored.…”

Null hypersurface caustics for high dimensional superentropic black holes

“…The superentropic black hole is the first example violating the RII. Soon afterward, a lot of new ultraspinning AdS black hole solutions [9][10][11][12][13][14] from some known rotating AdS black holes have been generated successfully. The singly rotating Kerr-AdS ultaspinning black holes in arbitrary dimensions as well as singly rotating ultraspinning black hole of five-dimensional minimal gauged supergravity theory satisfy the relation R < 1 [9].…”