scholarly journals Squashed black holes at large D

2021 ◽  
Vol 2021 (12) ◽  
Author(s):  
Ryotaku Suzuki ◽  
Shinya Tomizawa
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Static Solution ◽  
Flow Equation ◽  
Effective Theory ◽  
Theory Approach ◽  
First Order ◽  
Extremal Limit ◽  
Horizon Geometry ◽  
Kaluza Klein

Abstract Using the large D effective theory approach, we construct a static solution of non-extremal and squashed black holes with/without an electric charge, which describes a spherical black hole in a Kaluza-Klein spacetime with a compactified dimension. The asymptotic background with a compactified dimension and near-horizon geometry are analytically solved by the 1/D expansion. Particularly, our work demonstrates that the large D limit can be applied to solve the non-trivial background with a compactified direction, which leads to a first-order flow equation. Moreover, we show that the extremal limit consistently reproduces the known extremal result.

scholarly journals Extremal charged Vaidya and its near horizon geometry

2017 ◽  
Vol 26 (04) ◽  
pp. 1750036
Author(s):  
S. Sadeghian ◽  
A. Shafiekhani
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Black Hole Solution ◽  
Spherically Symmetric ◽  
Nonstationary Solution ◽  
Vaidya Black Hole ◽  
Extremal Limit ◽  
Horizon Geometry ◽  
Extremal Black Holes

Recently [Formula: see text]-dimensional spherically symmetric charged Vaidya black hole solution has been constructed. We observe that this nonstationary solution admits extremal limit and study its near horizon geometry. We show that the symmetry of the near horizon geometry is [Formula: see text]. Our analysis shows that the theorems for the near horizon geometry of stationary extremal black holes, may be extended to nonstationary cases.

scholarly journals A new spin on the Weak Gravity Conjecture

2021 ◽  
Vol 2021 (3) ◽  
Author(s):  
Lars Aalsma ◽  
Alex Cole ◽  
Gregory J. Loges ◽  
Gary Shiu
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Mild Form ◽  
Black String ◽  
Charged Black Holes ◽  
Higher Derivative ◽  
Horizon Geometry ◽  
Weak Gravity ◽  
Extremal Black Holes ◽  
Kaluza Klein

Abstract The mild form of the Weak Gravity Conjecture states that quantum or higher-derivative corrections should decrease the mass of large extremal charged black holes at fixed charge. This allows extremal black holes to decay, unless protected by a symmetry (such as supersymmetry). We reformulate this conjecture as an integrated condition on the effective stress tensor capturing the effect of quantum or higher-derivative corrections. In addition to charged black holes, we also consider rotating BTZ black holes and show that this condition is satisfied as a consequence of the c-theorem, proving a spinning version of the Weak Gravity Conjecture. We also apply our results to a five-dimensional boosted black string with higher-derivative corrections. The boosted black string has a BTZ×S2 near-horizon geometry and, after Kaluza-Klein reduction, describes a four-dimensional charged black hole. Combining the spinning and charged Weak Gravity Conjecture we obtain positivity bounds on the five-dimensional Wilson coefficients that are stronger than those obtained from charged black holes alone.

scholarly journals Rotating 5D black holes: Interactions and deformations near extremality

2021 ◽  
Vol 11 (6) ◽  
Author(s):  
Alejandra Castro ◽  
Juan Pedraza ◽  
Chiara Toldo ◽  
Evita Verheijden
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Degrees Of Freedom ◽  
Effective Theory ◽  
Extremal Black Hole ◽  
Massive Scalar Field ◽  
Five Dimensions ◽  
Interesting Insight ◽  
Angular Momenta ◽  
Horizon Geometry

We study a two-dimensional theory of gravity coupled to matter that is relevant to describe holographic properties of black holes with two equal angular momenta in five dimensions (with or without cosmological constant). We focus on the near-horizon geometry of the near-extremal black hole, where the effective theory reduces to Jackiw-Teitelboim (JT) gravity coupled to a massive scalar field. We compute the corrections to correlation functions due to cubic interactions present in this theory. A novel feature is that these corrections do not have a definite sign: for AdS_55 black holes the sign depends on the mass of the extremal solution. We discuss possible interpretations of these corrections from a gravitational and holographic perspective. We also quantify the imprint of the JT sector on the UV region, i.e. how these degrees of freedom, characteristic for the near-horizon region, influence the asymptotically far region of the black hole. This gives an interesting insight on how to interpret the IR modes in the context of their UV completion, which depends on the environment that contains the black hole.

scholarly journals Uptunneling to de Sitter

2020 ◽  
Vol 2020 (9) ◽  
Author(s):  
Mehrdad Mirbabayi
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
False Vacuum ◽  
De Sitter ◽  
Dimensional Theory ◽  
Hole Geometry ◽  
Horizon Geometry ◽  
Two Sides ◽  
Extremal Black Holes

Abstract We propose a Euclidean preparation of an asymptotically AdS2 spacetime that contains an inflating dS2 bubble. The setup can be embedded in a four dimensional theory with a Minkowski vacuum and a false vacuum. AdS2 approximates the near horizon geometry of a two-sided near-extremal Reissner-Nordström black hole, and the two sides can connect to the same Minkowski asymptotics to form a topologically nontrivial worm- hole geometry. Likewise, in the false vacuum the near-horizon geometry of near-extremal black holes is approximately dS2 times 2-sphere. We interpret the Euclidean solution as describing the decay of an excitation inside the wormhole to a false vacuum bubble. The result is an inflating region inside a non-traversable asymptotically Minkowski wormhole.

scholarly journals ON THE CFT DUALS FOR NEAR-EXTREMAL BLACK HOLES

2011 ◽  
Vol 26 (22) ◽  
pp. 1601-1611 ◽  
Author(s):  
JØRGEN RASMUSSEN
Keyword(s):  
Field Theory ◽  
Black Holes ◽  
Black Hole ◽  
Conformal Field Theory ◽  
Two Dimensional ◽  
Conformal Field ◽  
Horizon Geometry ◽  
Cardy Formula ◽  
Asymptotic Symmetries ◽  
Extremal Black Holes

We consider Kerr–Newman–AdS–dS black holes near extremality and work out the near-horizon geometry of these near-extremal black holes. We identify the exact U (1)L× U (1)R isometries of the near-horizon geometry and provide boundary conditions enhancing them to a pair of commuting Virasoro algebras. The conserved charges of the corresponding asymptotic symmetries are found to be well-defined and nonvanishing and to yield central charges cL≠0 and cR = 0. The Cardy formula subsequently reproduces the Bekenstein–Hawking entropy of the black hole. This suggests that the near-extremal Kerr–Newman–AdS–dS black hole is holographically dual to a non-chiral two-dimensional conformal field theory.

scholarly journals Deforming charged black holes with dipolar differential rotation boundary

2020 ◽  
Vol 80 (7) ◽  
Author(s):  
Tong-Tong Hu ◽  
Shuo Sun ◽  
Hong-Bo Li ◽  
Yong-Qiang Wang
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Chemical Potential ◽  
Dimensional Space ◽  
Quasinormal Modes ◽  
Fixed Temperature ◽  
First Case ◽  
Ads Black Holes ◽  
Horizon Geometry ◽  
Black Hole Solutions

Abstract Motivated by the recent studies of the novel asymptotically global $$\hbox {AdS}_4$$AdS4 black hole with deformed horizon, we consider the action of Einstein–Maxwell gravity in AdS spacetime and construct the charged deforming AdS black holes with differential boundary. In contrast to deforming black hole without charge, there exists at least one value of horizon for an arbitrary temperature. The extremum of temperature is determined by charge q and divides the range of temperature into several parts. Moreover, we use an isometric embedding in the three-dimensional space to investigate the horizon geometry. The entropy and quasinormal modes of deforming charged AdS black hole are also studied in this paper. Due to the existence of charge q, the phase diagram of entropy is more complicated. We consider two cases of solutions: (1) fixing the chemical potential $$\mu $$μ; (2) changing the value of $$\mu $$μ according to the values of horizon radius and charge. In the first case, it is interesting to find there exist two families of black hole solutions with different horizon radii for a fixed temperature, but these two black holes have same horizon geometry and entropy. The second case ensures that deforming charged AdS black hole solutions can reduce to standard RN–AdS black holes.

scholarly journals REGULAR BLACK HOLES IN AN ASYMPTOTICALLY DE SITTER UNIVERSE

2008 ◽  
Vol 23 (40) ◽  
pp. 3377-3392 ◽  
Author(s):  
JERZY MATYJASEK ◽  
DARIUSZ TRYNIECKI ◽  
MARIUSZ KLIMEK
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Nonlinear Electrodynamics ◽  
Spherically Symmetric ◽  
De Sitter ◽  
Coupled Equations ◽  
Sitter Universe ◽  
De Sitter Universe ◽  
Horizon Geometry ◽  
Interesting Solution

A regular solution of the system of coupled equations of the nonlinear electrodynamics and gravity describing static and spherically-symmetric black holes in an asymptotically de Sitter universe is constructed and analyzed. Special emphasis is put on the degenerate configurations (when at least two horizons coincide) and their near horizon geometry. It is explicitly demonstrated that approximating the metric potentials in the region between the horizons by simple functions and making use of a limiting procedure one obtains the solutions constructed from maximally symmetric subspaces with different absolute values of radii. Topologically they are AdS2×S2 for the cold black hole, dS2×S2 when the event and cosmological horizon coincide, and the Plebański–Hacyan solution for the ultraextremal black hole. A physically interesting solution describing the lukewarm black holes is briefly analyzed.

scholarly journals Kaluza-Klein-Kerr-Godel Black Holes: Kaluza-Klein Black Holes with Rotations of Black Hole and Universe

2009 ◽  
Vol 121 (4) ◽  
pp. 823-841 ◽  
Author(s):  
S. Tomizawa ◽  
H. Ishihara ◽  
K. Matsuno ◽  
T. Nakagawa
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Kaluza Klein

scholarly journals Cosmic cloaking of rich extra dimensions

2021 ◽  
Author(s):  
Aghil Alaee ◽  
Marcus Khuri ◽  
Hari Kunduri
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Extra Dimensions ◽  
Large Extra Dimensions ◽  
Dimensional Theory ◽  
Hoop Conjecture ◽  
Significant Size ◽  
The Universe ◽  
Lower Dimensional ◽  
Kaluza Klein

We present arguments that show why it is difficult to see rich extra dimensions in the universe. Conditions are found where significant size and variation of the extra dimensions in a Kaluza–Klein compactification lead to a black hole in the lower-dimensional theory. The idea is based on the hoop conjecture concerning black hole existence, as well as on the observation that dimensional reduction on macroscopically large, twisted, or highly dynamical extra dimensions contributes positively to the energy density in the lower-dimensional theory and can induce gravitational collapse. A threshold for the size is postulated on the order of [Formula: see text][Formula: see text]m, whereby extra dimensions of length above this level must lie inside black holes, thus cloaking them from the view of outside observers. The threshold depends on the size of the universe, leading to speculation that in the early stages of evolution truly macroscopic and large extra dimensions would have been visible.

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