It is often argued that {\it all the information of a gravitational theory is encoded in the surface term of the action}; which means one can find several physical quantities just from the surface term without incorporating the bulk part of the action. This has been observed in various instances; e.g. derivation of the Einstein's equations, surface term calculated on the horizon leads to entropy, etc. Here I investigate the role of it in the context of entropy function and entropy of extremal near horizon black holes. Considering only the Gibbons-Hawking-York (GHY) surface term to define an entropy function for the extremal near horizon black hole solution, it is observed that the extremization of such function leads to the exact value of the horizon entropy. This analysis again supports the previous claim that there exists a ``{\it holographic}'' nature in the gravitational action -- surface term contains the information of the bulk.
The island rule for the entanglement entropy is applied to an eternal Reissner-Nordström black hole. The key ingredient is that the black hole is assumed to be in thermal equilibrium with a heat bath of an arbitrary temperature and so the generalized entropy is treated as being off-shell. Taking the on-shell condition to the off-shell generalized entropy, we find the generalized entropy and then obtain the entanglement entropy following the island rule. For the non-extremal black hole, the entanglement entropy grows linearly in time and can be saturated after the Page time as expected. The ent…
A classification of near-horizon geometries of extremal vacuum black holes
我们考虑极端的近视界几何，旋转黑洞的真空爱因斯坦方程的解决方案，包括一个负的宇宙学常数，在四维和五维。我们假设存在一个旋转对称的4D，两个交换旋转对称的5D和在这两种情况下的非环形地平线拓扑。在4d中，我们确定了这种黑洞的最一般的近视界几何，并证明了它与极值Kerr-AdS（4）黑洞的近视界极限相同.在5d中，没有宇宙学常数，我们确定了所有可能的近视界的黑洞的几何形状。我们证明了唯一的可能性是一个具有拓扑S^1 X S^2视界的族和两个具有拓扑S^3视界的不同族。S^1 X S^2族包含了提升极值克尔弦的近视界极限和极值真空黑环。第一种拓扑球形情形与两种不同的黑洞解的近视界极限相同：极端的Myers-Perry黑洞和缓慢旋转的极端的Kaluza-Klein（KK）黑洞.第二种拓扑球情形包含了快速旋转极值KK黑洞的近视界极限。最后，在宇宙学常数为负的5维情形下，我们将问题归结为求解一个函数的六阶非线性常微分方程。这使我们能够恢复已知的拓扑S^3极端旋转AdS（5）黑洞的近视界极限。进一步，我们构造了一个近似解对应于一个小的，极值AdS（5）黑环的近地平线几何。
We investigate the separability of Klein-Gordon equation on near horizon of d-dimensional rotating Myers-Perry black hole in two limits : 1) generic extremal case and 2) extremal vanishing horizon case. In the first case , there is a relation between the mass and rotation parameters so that black hole temperature vanishes. In the latter case, one of the rotation parameters is restricted to zero on top of the extremality condition. We show that the Klein-Gordon equation is separable in both cases. Also, we solved the radial part of that equation and discuss its behaviour in small and large r re…
We study all transverse deformations of the extremal Reissner-Nordström-(A)dS horizon in the Einstein-Maxwell theory. No symmetry assumptions are needed. It is shown that for the generic values of the charge, the only allowed deformation is spherically symmetric. However, it is shown that for fine-tuned values of a charge, the space of deformations is larger, yet still finite-dimensional.
Institut für Theoretische Physik, Max-von-Laue-Str. 1, 60438 Frankfurt, Germany（法兰克福理论物理研究所）；Center for Gravitational Physics and Quantum Information, Yukawa Institute for Theoretical Physics, Kyoto University, Kyoto 606-8502, Japan（京都大学引力物理与量子信息中心、汤川理论物理研究所）；Research Center for the Early Universe (RESCEU), Graduate School of Science, The University of Tokyo, Hongo 7-3-1, Bunkyo-ku, Tokyo 113-0033, Japan（东京大学理学研究宇宙早期研究中心（RESCEU））；Kavli Institute for the Physics and Mathematics of the Universe (WPI), The University of Tokyo Institutes for Advanced Study, The University of Tokyo, Kashiwa, Chiba 277-8583, Japan（东京大学宇宙物质科学 Kavli 研究所（WPI））；Departamento de Física, Universidad del País Vasco UPV/EHU, Apartado 644, 48080 Bilbao, Spain（巴斯克大学物理系）；EHU Quantum Center, Universidad del País Vasco UPV/EHU（巴斯克大学 EHU 量子中心）
There is a well-established connection between the higher-derivative corrections to the black hole entropy and the black hole extremality bound. The particular combination of EFT coefficients $c_i$ that controls the mass shift at fixed charge and temperature also controls the entropy shift at fixed charge and mass in the limit where the mass approaches the uncorrected value for the extremal mass. In this note, we use the classical entropy function formalism to examine the entropy corrections at exactly zero temperature, or at the corrected value for the extremal mass. We find that the zero-tem…
We extend our previous work in which we derived the most general form of an induced metric describing the geometry of an axially symmetric extremal isolated horizon (EIH) in asymptotically flat spacetime. Here we generalize it to EIHs in asymptotically (anti-)de Sitter spacetime. The resulting metric conveniently forms a 6-parameter family which, in addition to a cosmological constant $Λ$, depends on the area of the horizon, total electric and magnetic charges, and two deficit angles representing conical singularities at poles. Such a metric is consistent with results obtained in the context o…
We analyze the near horizon symmetry of the extremal Kerr black hole within the framework of Poincaré gauge theory (PG) for two important limiting cases: Riemannian and teleparallel solution. We show that the algebra of canonical generators is realized by Virasoro algebra, with central charge which depends on the black hole horizon radius . The conformal entropy of the black hole is obtained via Cardy formula.
We show that the Aretakis instability of compact extremal horizons persists in the planar case of interest to holography and discuss its connection with the emergence of "semi-local quantum criticality" in the field theory dual. In particular, the spatially localized power-law decay of this critical phase corresponds to spatially localized power-law growth of stress-energy on the horizon. For near-extremal black holes these phenomena occur transiently over times of order the inverse temperature. The boundary critical phase is characterized by an emergent temporal conformal symmetry, and the bu…
We systematically investigate axisymmetric extremal isolated horizons (EIHs) defined by vanishing surface gravity, corresponding to zero temperature. In the first part, using the Newman-Penrose and GHP formalism we derive the most general metric function for such EIHs in the Einstein-Maxwell theory, which complements the previous result of Lewandowski and Pawlowski. We prove that it depends on 5 independent parameters, namely deficit angles on the north and south poles of a spherical-like section of the horizon, its radius (area), and total electric and magnetic charges of the black hole. The …
Taming the Aretakis instability: extremal black holes with multi-degenerate horizons
International School for Advanced Studies (SISSA)（高等研究国际学院）；National Institute for Nuclear Physics (INFN), Sezione di Trieste（意大利国家核物理研究所的里雅斯特分部）；Institute for Fundamental Physics of the Universe (IFPU)（宇宙基础物理研究所）
We compute the Bekenstein-Hawking entropy of near-extremal asymptotically AdS$_4$ electrically charged rotating black holes using three different methods: (i) from the gravity solution, (ii) from the near-horizon Kerr/CFT correspondence and (iii) from the boundary conformal field theory. The results from these three different approaches match exactly, giving us a unique and universal expression for the entropy and the microstate counting of near-extremal AdS black holes via the AdS/CFT correspondence. In the second method, we extend the Kerr/CFT correspondence to the near-extremal case to comp…
Logarithmic corrections to the entropy of near-extremal rotating black holes
Indian Institute of Science Education and Research Bhopal（印度科学教育研究所博帕尔分校）；International Centre for Theoretical Sciences - TIFR Bengaluru（理论科学国际中心 - 提弗尔大学班加罗尔）
