AdS Black Holes Research Articles

On the uniqueness of supersymmetric AdS(5) black holes with toric symmetry

We consider the classification of supersymmetric AdS5 black hole solutions to minimal gauged supergravity that admit a torus symmetry. This problem reduces to finding a class of toric Kähler metrics on the base space, which in symplectic coordinates are determined by a symplectic potential. We derive the general form of the symplectic potential near any component of the horizon or axis of symmetry, which determines its singular part for any black hole solution in this class, including possible new solutions such as black lenses and multi-black holes. We find that the most general known black hole solution in this context, found by Chong, Cvetic, Lü and Pope (CCLP), is described by a remarkably simple symplectic potential. We prove that any supersymmetric and toric solution that is timelike outside a smooth horizon, with a Kähler base metric of Calabi type, must be the CCLP black hole solution or its near-horizon geometry.

Microstructure of charged AdS black hole with minimal length effects* *Supported by NSFC (11947408, 12047573)

In this work, the microstructure of charged AdS black holes under minimal length effects is investigated. We study the thermodynamics of black holes in the extended phase space, where the cosmological constant is regarded as the thermodynamic pressure. The modified Hawking temperature and phase transition are obtained based on the generalized uncertainty principle (GUP). Then, using thermodynamic geometry, the microstructure of black holes can be determined by the ratio of the GUP parameter to charge. For a small ratio, the black hole exhibits the typical RN-AdS microstructure with van der Waals phase transition and repulsive/attractive interactions. As the ratio increases, the reentrant phase transition is observed, and both the repulsion-attraction coexisted and the attraction dominated black holes are noted. For a large ratio, the black hole behaves like a Schwarzchild-AdS black hole in which neither phase transition nor repulsive interaction are observed. These results suggest that the GUP effect will reduce the repulsive interaction presented by the charged AdS black hole.

Addendum to “Radiation emitted by a source orbiting a Schwarzschild–anti–de Sitter black hole”

In [J. P. B. Brito et al., Phys. Rev. D 104, 124085 (2021).], we studied the scalar radiation emitted by a source orbiting a Schwarzschild--anti--de Sitter black hole along circular geodesics. We presented results for the emitted power in the context of quantum field theory in curved spacetimes. We computed the emitted power for a region of the parameter space corresponding to large black holes when compared to the anti--de Sitter radius. In this addendum we investigate the regime of small black holes, i.e., the regime of ${M}^{2}\mathrm{\ensuremath{\Lambda}}\ensuremath{\lesssim}0$. In this regime, the emitted power, as a function of the source's angular velocity, exhibits resonant peaks associated with quasinormal frequencies.

Corrections to AdS5 black hole thermodynamics from higher-derivative supergravity

We study four-derivative corrections to five-dimensional minimal gauged supergravity. We evaluate the on-shell action of the AdS5 black hole solution with two independent angular momenta and one electric charge at linear order in the corrections. After imposing supersymmetry, we are able to recast the action in terms of the supersymmetric chemical potentials and match the result obtained from the dual superconformal index on the second sheet. To achieve this, we exploit the freedom to implement field redefinitions to recast the action in a much simpler form, as well as the fact that the two-derivative solution is enough. We use the on-shell action to determine the corrections to the black hole thermodynamics, including those to the entropy and the charges. We then specialize to the supersymmetric and extremal case and find a simple expression for the microcanonical entropy. In particular, for the case with one independent angular momentum the corrections are entirely encoded in the dual superconformal anomaly coefficients. We corroborate this result for the entropy by constructing the corrected near-horizon solution and applying Wald’s formula.

A varying gravitational constant map in asymptotically AdS black hole thermodynamics

We propose a sequence of steps and a generic transformation for connecting common thermodynamic quantities considered in asymptotically anti-de Sitter black hole thermodynamics in the bulk and those that are appropriate for CFT thermodynamics in the boundary. We do this by constructing a “varying-G map”, where G is the gravitational constant, and demonstrate its usefulness by considering various examples.

Bouncing inside the horizon and scrambling delays

We study charged perturbations of the thermofield double state dual to a charged AdS black hole. We model the perturbation by a massless charged shell in the bulk. Unlike the neutral case, all such shells bounce at a definite radius, which can be behind the horizon. We show that the standard “shock wave” calculation of a scrambling time indicates that adding charge increases the scrambling time. We then give two arguments using the bounce that suggest that scrambling does not actually take longer when charge is added, but instead its onset is delayed. We also construct a boundary four point function which detects whether the shell bounces inside the black hole.

Two-dimensional Lifshitz-like AdS black holes in F(R) gravity

Two-dimensional (2D) Lifshitz-like black holes in special F(R) gravity cases are extracted. We indicate an essential singularity at r = 0, covered by an event horizon. Then, conserved and thermodynamic quantities, such as temperature, mass, entropy, and the heat capacity of 2D Lifshitz-like black holes in F(R) gravity, are evaluated. Our analysis shows that 2D Lifshitz-like black hole solutions can be physical solutions, provided that the cosmological constant is negative (Λ < 0). Indeed, there is a phase transition between stable and unstable cases by increasing the radius of AdS black holes. In other words, the 2D Lifshitz-like AdS black holes with large radii are physical and enjoy thermal stability. The obtained 2D Lifshitz-like AdS-black holes in F(R) gravity turn into the well-known 2D Schwarzschild AdS-black holes when the Lifshitz-like parameter is zero (s = 0). Moreover, correspondence between these black hole solutions and the 2D rotating black hole solutions is found by adjusting the Lifshitz-like parameter.

Stringy ER = EPR

The ER = EPR correspondence relates a superposition of entangled, disconnected spacetimes to a connected spacetime with an Einstein-Rosen bridge. We construct examples in which both sides may be described by weakly-coupled string theory. The relation between them is given by a Lorentzian continuation of the FZZ duality of the two-dimensional Euclidean black hole CFT in one example, and in another example by continuation of a similar duality that we propose for the asymptotic Euclidean AdS3 black hole. This gives a microscopic understanding of ER = EPR: one has a worldsheet duality between string theory in a connected, eternal black hole, and in a superposition of disconnected geometries in an entangled state. The disconnected description includes a condensate of entangled folded strings emanating from a strong-coupling region in place of a bifurcation point. Our construction relies on a Lorentzian interpretation of Euclidean time winding operators via angular quantization, as well as some lesser known worldsheet string theories, such as perturbation theory around a thermofield-double state, which we define using Schwinger-Keldysh contours in target space.

Analytic solutions of neutral hyperbolic black holes with scalar hair

We find analytic solutions of hyperbolic black holes with scalar hair in anti-de Sitter (AdS) space, and they do not have spherical or planar counterparts. The system is obtained by taking a neutral limit of an Einstein-Maxwell-dilaton system whose special cases are maximal gauged supergravities, while the dilaton is kept nontrivial. There are phase transitions between these black holes and the hyperbolic Schwarzschild-AdS black hole. We discuss two AdS/CFT applications of these hyperbolic black holes. One is phase transitions of holographic Renyi entropies, and the other is phase transitions of quantum field theories in de Sitter space. In addition, we give a C-metric solution as a generalization of the hyperbolic black holes with scalar hair.

Holographic Einstein ring of a charged AdS black hole

Taking into account that the real quantum materials are engineered generically at a finite chemical potential, we investigate the Einstein ring structure for the lensed response of the complex scalar field as a probe wave on the charged AdS black hole in the context of AdS/CFT. On the one hand, we find that the resulting Einstein ring radius has no variation with the chemical potential, which is similar to the behavior for the weakly interacting quantum system. On the other hand, not only can such a ring exist well within the screen, but also the temperature dependence of its radius exhibits a distinct feature in the sense that it displays an appreciable increase at low temperatures while the ring keeps unchanged right at the edge of the screen for the weakly interacting system. Note that such a Einstein ring emerges in the large frequencies and can be well captured by the photon sphere away from the black hole horizon in the geometric optics approximation, thus such a distinct feature may be regarded as a universal behavior associated with the high energy modes of the strongly coupled system which has a gravity dual.

The radial distribution function reveals the underlying mesostructure of the AdS black hole

Based on the equations of state, one can infer the underlying interaction potentials among the black hole molecules in the case of Schwarzschild-AdS and charged AdS black holes. The microscopic molecules with the interaction potential arrange in a specific way to form the mesostructure, whose size is between the macro (black hole system) and the micro (black hole molecules). As a result, the mesostructure leads to the emergence of the macroscopic phase. However, the information about the mesostructure of the AdS black hole are still elusive. In this paper, the radial distribution function is introduced to probe the mesostructure of the AdS black hole. We find that the mesostructure of the Schwarzschild-AdS black hole behaves as the ideal gas when the temperature is high. Furthermore, we find the mesostructure for the liquid-like (gas-like) phase of the small (large) charged AdS black hole. A sudden change of the mesostructure emerges from the liquid-like phase to the gas-like phase when the charged AdS black hole undergoes a phase transition from the small to large black hole, consistent with the viewpoint that the phase transition of the charged AdS black hole is reminiscent of that of the vdW fluid. This study provides a new angle towards understanding the black hole from its mesostructure.

Novel logarithmic corrections to black hole entropy

For a thermodynamic system, apart from thermal fluctuations, there are also fluctuations in thermodynamic volume when the system is in contact with a volume reservoir. For the case of black holes in anti-de Sitter spacetimes, the effect of thermal fluctuations on the entropy is well studied. The aim of this work is to compute novel logarithmic corrections to black hole entropy coming from simultaneous fluctuations of energy and thermodynamic volume. We work in the isothermal-isobaric ensemble and first obtain a general form of corrections to entropy which are valid for any thermodynamic system. Applying the formalism to Kerr black holes in AdS reveals that the black hole entropy gets corrected as: where S 0 is given by the Bekenstein–Hawking formula and k = −1. The same leading coefficient is also obtained in the canonical ensemble, i.e. by considering energy fluctuations alone. This coefficient is found to be unaltered in the slowly rotating and high temperature limits.

Gravitational decoupling for hairy black holes in asymptotic AdS spacetimes* *D. C. Zou acknowledges financial support from the Outstanding Young Teacher programme of Yangzhou University (137050368).

In this study, the gravitational decoupling approach via extended geometric deformation is utilized to generate analytical black hole solutions owing to its simplicity and effectiveness. Considering the external fields surrounding Schwarzschild AdS black holes, we derive hairy black hole solutions in asymptotic AdS spacetime, satisfying the strong and dominant energy conditions. Moreover, we find that if the black hole spacetime is a fluid system, the fluid under each of these conditions is anisotropic.

Bounds on gravitational brane couplings and tomography in AdS3 black hole microstates

We study information theoretic properties of planar black hole microstates in 2 + 1 dimensional asymptotically anti-de Sitter spacetime, modeled by black holes with an end-of-the-world brane behind the horizon. The von Neumann entropy of sufficiently large subregions in the dual CFT exhibits a time-dependent phase, which from a doubly-holographic perspective corresponds to the appearance of quantum extremal islands in the brane description. Considering the case where dilaton gravity is added to the brane, we show that tuning the associated couplings affects the propagation of information in the dual CFT state. By requiring that information theoretic bounds on the growth of entanglement entropy are satisfied in the dual CFT, we can place bounds on the allowed values of the couplings on the brane. Furthermore, we initiate the study of brane tomography, by showing how subleading corrections to the entanglement velocity can be used to learn about the properties of the brane as well as any gravitational dynamics localized on it.

Electromagnetic quasinormal modes of Schwarzschild–anti–de Sitter black holes: Bifurcations, spectral similarity, and exact solutions in the large black hole limit

We revisit the peculiar electromagnetic quasinormal mode spectrum of an asymptotically anti-de Sitter Schwarzschild black hole. Recent numerical calculations have shown that some quasinormal mode frequencies become purely overdamped at some critical black hole sizes, where the spectrum also bifurcates. In this paper, we shed light on unnoticed and unexplained properties of this spectrum by exploiting some novel analytic results for the large black hole limit. We demonstrate, both numerically and analytically, that the quasinormal mode spectra of large black holes become approximately isospectral, and refer to this new symmetry property as spectral similarity. We take advantage of this spectral similarity to derive a precise analytic expression for the locations of the bifurcations, in which a surprising Feigenbaum-like constant appears. We derive an exact solution for its spectrum and eigenfunctions, and find that large black holes cannot be made to vibrate with electromagnetic perturbations, independently of the boundary conditions imposed at spatial infinity. Finally, we characterize the insensitivity of the spectrum to different boundary conditions by analyzing the expansion of the quasinormal mode spectrum around the large black hole limit.

Phase transitions for charged planar solitons in AdS

In this work we study the phase transitions between the planar charged AdS black hole and the planar charged soliton. The planar soliton is obtained as a double analytic continuation of the charged black hole metric, which also involves analytically continuing the electric charge. We show that there are phase transitions between both solutions depending on the electric potential, magnetic flux and temperature. The analysis is carried out in the grand-canonical ensemble.

Thermodynamics of a quantum corrected Schwarzschild black hole in AdS spacetime

The thermodynamics for a quantum corrected Schwarzschild black hole with AdS background is investigated. First, the black hole metric is introduced and given when the spherical symmetric quantum fluctuations of spacetime are considered for Schwarzschild AdS black hole. Then, based on AdS background, we get the free energy for the quantum corrected black hole by AdS gravity renormalization and saddle-point approximation. By the spherical symmetric quantum fluctuation in AdS spacetime is considered, there are three main results found. Firstly, due to quantum fluctuation, there is a divergence term in the Euclidean action, which contributes to the energy of spacetime. Secondly, the entropy of the modified black hole is still proportional to the horizon area. But when the contribution of quantum fluctuations is deducted, the relationship between entropy and area is not so. It shows that, the area entropy theorem for the black hole is the both effect of quantum fluctuations and black hole. Thirdly, quantum fluctuation doesn't affect the temperature of Hawking-Page transition, but the radius of the black hole of Hawking-Page transition will be corrected.

Upper bounds of holographic entanglement entropy growth rate for thermofield double states

We studied the upper bounds of the holographic entanglement entropy growth rate for thermofield double (TFD) states. By comparing the cases of vacuum AdS and charged AdS black holes, we conjecture: for all static planar or spherically symmetric asymptotically Schwarzschild-AdS black holes of same mass density or entropy density, the vacuum AdS black hole gives the maximum entanglement entropy growth rate. We gave proofs by assuming dominant energy condition. We also considered the AdS black hole spacetime with real scalar fields case, where the scalar fields violate the dominant energy condition and the bulk geometry is not asymptotically Schwarzschild-AdS. Numerical results show that this case vacuum black hole still has maximal growth rate if we fixed entropy. However, in the case of fixed energy, vacuum case has maximal growth rate of entanglement entropy only under standard quantization scheme.

Towards the construction of multi-centered black holes in AdS

We find a class of approximate perturbative solutions describing multi-centered BPS black holes in asymptotically AdS4. These black holes are moving coplanarly in a circular orbit with common radius but fixed phase differences, where the radius is characterized by a common boost velocity v. While the solutions are not complete, as they are only accurate up to mathcal{O} (M2v2), we are able to locally investigate their supersymmetric properties in four-dimensional mathcal{N} = 2 supergravity. The result indicates that, while a single BPS black hole preserves half of the supersymmetries, a configuration with two or more black holes is only 1/4 BPS. These perturbative solutions reduce in the asymptotically Minkowski limit to the multi-black hole solution of Majumdar and Papapetrou.

Noncommutative Corrections to the Minimal Surface Areas of the Pure AdS Spacetime and Schwarzschild-AdS Black Hole

Based on the perturbation expansion, we compute the noncommutative corrections to the minimal surface areas of the pure AdS spacetime and Schwarzschild-AdS black hole, where the noncommutative background is suitably constructed in terms of the Poincaré coordinate system. In particular, we find a reasonable tetrad with subtlety, which not only matches the metrics of the pure AdS spacetime and Schwarzschild-AdS black hole in the commutative case, but also makes the corrections real rather than complex in the noncommutative case. For the pure AdS spacetime, the nocommutative effect is only a logarithmic term, while for the Schwarzschild-AdS black hole, it contains a logarithmic contribution plus both a mass term and a noncommutative parameter related term. Furthermore, we show that the holographic entanglement entropy with noncommutativity obeys a relation which is similar to the first law of thermodynamics in the pure AdS spacetime.