Article
Physics, Particles & Fields
Chen-Hao Wu, Ya-Peng Hum, Hao Xu
Summary: The Einstein-Gauss-Bonnet theory explores the evaporation process of black holes by introducing higher order curvature terms, revealing that the black hole lifetime is dependent on dimensions and coupling constant. In certain cases, black holes completely evaporate, while in others they become remnants.
EUROPEAN PHYSICAL JOURNAL C
(2021)
Article
Physics, Particles & Fields
Aofei Sang, Ming Zhang, Shao-Wen Wei, Jie Jiang
Summary: Black hole echo is a significant observable that helps in comprehending gravitational theories. Non-linear electrodynamic black holes can have multiple horizons, and the destruction of outer horizons doesn't violate the weak cosmic censorship, resulting in a multi-peak effective potential for scalar perturbations and generating echoes. By studying the splitting of the time-domain profile when the peaks of the effective potential change from two to three, we can potentially determine the geometric structure of non-linear electrodynamic black holes. Additionally, we analyze the properties of echoes produced by different types of effective potentials.
EUROPEAN PHYSICAL JOURNAL C
(2023)
Article
Astronomy & Astrophysics
Li Li
Summary: The presence of a scalar hair in black holes leads to an additional contribution to the first law of black hole thermodynamics, which requires modification including new thermodynamic conjugate variables phi(s) and (O). The study provides a deeper understanding of the thermodynamics of AdS black holes in Einstein-scalar gravity and sheds light on the behavior of the scalar field near the AdS boundary.
Article
Physics, Nuclear
Hongmei Jing, Benrong Mu, Jun Tao, Peng Wang
Summary: The study shows that the instability conjecture holds true when nonlinear electrodynamics effects are weak. However, the conjecture can be violated in some parameter regions with strong enough nonlinear electrodynamics effects, providing a counterexample to the idea that super-entropic black holes may be thermodynamically stable.
Article
Physics, Particles & Fields
Wen-Bin Xu, Shao-Feng Wu
Summary: Based on the AdS/CFT correspondence, this study investigates the reconstruction of bulk spacetime metrics using various quantum information measures on the boundary field theories. Different reconstruction methods are proposed, all of which avoid UV divergence and are driven by derivatives of the measures with respect to the boundary scales. It is demonstrated that the measures of spatial entanglement and time-evolved complexity can be used to reconstruct the exterior and interior of a black hole, respectively, and that the reconstruction method based on complexity=volume 2.0 is the simplest and exhibits strong locality.
JOURNAL OF HIGH ENERGY PHYSICS
(2023)
Article
Astronomy & Astrophysics
Di Wu, Shuang-Qing Wu
Summary: In this paper, we investigate the topological numbers of various black holes, including the singly rotating Kerr-AdS black holes in all dimensions, the four-dimensional Kerr-Newman-AdS black hole, and the three-dimensional Banados-Teitelboim-Zanelli black hole, while considering the influence of the cosmological constant and spacetime dimension. We find that the topological numbers of black holes are significantly affected by the cosmological constant and that the dimension of spacetimes plays a crucial role in determining the topological number for rotating AdS black holes. Furthermore, we make an interesting observation that the topological number of the AdS black hole is always one unit different from that of its corresponding asymptotically flat black hole, which leads us to propose a novel conjecture that needs further verification in future research on various black holes and their AdS counterparts.
Article
Physics, Particles & Fields
Abdulrahim Al Balushi, Robie A. Hennigar, Hari K. Kunduri, Robert B. Mann
Summary: In the study of holographic complexity for rotating black holes within the framework of complexity equals action and complexity equals volume conjectures, a simplification was found in a class of odd-dimensional equal-spinning black holes. A direct connection between complexity of formation and thermodynamic volume for large black holes was uncovered. The rate of growth of complexity was also examined, revealing that it approaches a constant at late times, but Lloyd's bound is generally violated.
JOURNAL OF HIGH ENERGY PHYSICS
(2021)
Article
Physics, Particles & Fields
Jose Luis Blazquez-Salcedo, Carlos A. R. Herdeiro, Sarah Kahlen, Jutta Kunz, Alexandre M. Pombo, Eugen Radu
Summary: In Einstein-Maxwell-scalar models, different classes of black hole solutions are obtained depending on the non-minimal coupling function. The quartic coupling function leads to cold and hot scalarized black hole branches, with only the cold branch having an unstable radial scalar-led mode. The scalar field in the scalarized background solutions breaks the degeneracy between axial and polar modes, with isospectrality slightly broken on the cold branch and strongly broken on the hot branch.
EUROPEAN PHYSICAL JOURNAL C
(2021)
Article
Astronomy & Astrophysics
Ming Zhang, Chaoxi Fang, Jie Jiang
Summary: Based on the complexity equals action (CA) and complexity equals volume (CV) conjectures, we investigate the holographic complexity of a slowly accelerating Kerr-AdS black hole in the bulk Einstein gravity theory which is dual to holographic states with rotation and conical deficits in the boundary quantum system. We evaluate the action and show that the growth rate of the CA complexity violates volume-scaling formulation in large black hole limit due to the non-trivial contribution from the not-too-small acceleration of the black hole. Moreover, we find that complexity of formation decreases with both the average and difference of the conical deficits on the poles when the black hole is close to the static limit but increases with the deficits when the black hole is close to the extremal regime.
Article
Astronomy & Astrophysics
Eugeny Babichev, William T. Emond, Sabir Ramazanov
Summary: We study black holes in a modified gravity scenario involving a scalar field quadratically coupled to the Gauss-Bonnet invariant. The nonminimal coupling to gravity leads to symmetry restoration near the black hole horizon, prompting the development of the scalar wall in its vicinity. The model is fully consistent with the existence of an inflationary stage and predicts the speed of gravitational waves to be extremely close to unity.
Article
Physics, Nuclear
Jie-Xiong Mo, Shan-Quan Lan
Summary: This study investigates the dynamic phase transition of charged dilaton black holes, revealing that with increasing parameter, the horizon radius difference between large and small dilaton black holes increases, the system requires more time to achieve a stationary distribution, and the dilaton field slows down the dynamic phase transition process between large and small black holes.
Article
Astronomy & Astrophysics
A. Belhaj, H. Belmahi, M. Benali, A. Segui
Summary: By using elliptic function analysis, we investigate the connection between AdS black hole thermodynamics and deflection angle variation, finding that stable and unstable phases can be derived from thermal variations of the deflection angle. This study suggests that the deflection angle can provide valuable information on the thermodynamics of AdS black holes.
Article
Astronomy & Astrophysics
Yves Brihaye, Betti Hartmann
Summary: We study the black hole solutions with scalar hair in the Einstein-Maxwell theory coupled to a complex scalar field. We find that new solutions exist for sufficiently large gravitational coupling and sufficiently small electromagnetic coupling. The scalar hair takes the form of a spatially oscillating 'wave packet' and affects the space-time such that the Ricci and Kretschmann scalars show similar oscillations.
CLASSICAL AND QUANTUM GRAVITY
(2022)
Article
Physics, Particles & Fields
Takaaki Ishii, Keiju Murata, Jorge E. Santos, Benson Way
Summary: In this study, rotating global AdS solutions in five-dimensional Einstein gravity coupled to a multiplet complex scalar within a cohomogeneity-1 ansatz were investigated. The onset of gravitational and scalar field superradiant instabilities of the Myers-Perry-AdS black hole lead to bifurcation points, resulting in black resonators and hairy Myers-Perry-AdS black holes, respectively. The solutions exhibit properties of multioscillating solutions with multiple scalar components excited. It was also observed that hairy black holes with higher scalar wavenumbers dominate entropy and occupy more phase space.
JOURNAL OF HIGH ENERGY PHYSICS
(2021)
Article
Astronomy & Astrophysics
G. G. L. Nashed
Summary: This research integrates an axionic field into the context of dynamical Chern-Simons gravity and explores the characteristics of a slowly rotating black hole within this theoretical framework. It is the first study to tackle this problem within the context of gravitational theory coupled with the axionic field. The investigation demonstrates the explicit expression of the enigmatic function U and reveals its potentials in generating significantly potent Chern-Simons black holes.
Article
Physics, Particles & Fields
Oscar J. C. Dias, Gary T. Horowitz, Jorge E. Santos
Summary: This study focuses on a family of charged black holes that develop scalar hair as their charge increases at fixed mass. Surprisingly, the maximum charge for a given mass corresponds to a nonsingular hairy black hole with nonzero Hawking temperature. The implications for Hawking evaporation are discussed.
JOURNAL OF HIGH ENERGY PHYSICS
(2022)
Article
Physics, Particles & Fields
Oscar J. C. Dias, Mahdi Godazgar, Jorge E. Santos
Summary: The frequency spectra of gravito-electromagnetic perturbations of the KN black hole have been computed and it has been found that there are two families of QNMs that display eigenvalue repulsion. The perturbation equations can be solved analytically using a near-horizon expansion, providing a good approximation to the numerical data near-extremality. This manuscript provides an extended study of these properties, including the derivation of a gauge invariant system of coupled PDEs, frequency approximations, and a deeper understanding of eigenvalue repulsion.
JOURNAL OF HIGH ENERGY PHYSICS
(2022)
Article
Physics, Particles & Fields
Donald Marolf, Jorge E. Santos
Summary: This study examines the stability of black hole saddles inside a spherical reflecting cavity, finding that coupled modes can be diagonalized in the Lichnerowicz operator to define a natural generalization of the pure-trace Wick-rotation recipe. This recipe reproduces the expected result from black hole thermodynamics, where large Euclidean black holes are stable saddles while small Euclidean black holes are unstable.
JOURNAL OF HIGH ENERGY PHYSICS
(2022)
Article
Physics, Particles & Fields
Gary T. Horowitz, Maciej Kolanowski, Jorge E. Santos
Summary: We studied the geometry near the horizon of a four-dimensional extremal black hole. When the cosmological constant is negative, we found that tidal forces diverge as one crosses the horizon, and this singularity is stronger for larger black holes. This applies to generic nonspherical black holes, and all scalar curvature invariants remain finite. Furthermore, nonextremal black holes have tidal forces that diverge in the extremal limit, reflecting in anomalous scaling of the specific heat with temperature holographically. Similar, albeit weaker, effects are present when the cosmological constant is positive, but not when it vanishes.
JOURNAL OF HIGH ENERGY PHYSICS
(2023)
Article
Physics, Particles & Fields
Donald Marolf, Jorge E. Santos
Summary: This study resolves the tension between the stability of the microcanonical ensemble for gravitating systems and the rapid decay of the negative mode of Schwarzschild black holes. By constructing the microcanonical partition function and applying Wick rotations, we obtained a positive definite action for linear perturbations. Most of the study was conducted in a cavity with reflecting boundary conditions.
JOURNAL OF HIGH ENERGY PHYSICS
(2022)
Article
Physics, Particles & Fields
William D. Biggs, Jorge E. Santos
Summary: We construct the holographic duals to a large N, strongly coupled N = 4 super Yang-Mills conformal field theory defined on a four-dimensional de Sitter-Schwarzschild background. There are two distinct five-dimensional bulk solutions: the static black tunnel with two disconnected horizons, and the black hammock with one horizon in the bulk. The hammock horizon is not a Killing horizon, possessing interesting properties like non-vanishing expansion and shear, and allowing classical flow along it.
JOURNAL OF HIGH ENERGY PHYSICS
(2022)
Article
Physics, Particles & Fields
Oscar J. C. Dias, Takaaki Ishii, Keiju Murata, Jorge E. E. Santos, Benson Way
Summary: We study the effect of superradiant scattering on the stability of rotating black strings, focusing on the six dimensional equal-spinning Myers-Perry black string. We find that rapidly rotating black strings are unstable to gravitational superradiant modes within a bounded range of string lengths. This instability arises due to the confinement of superradiant modes by a potential barrier created by momentum along the string direction. Furthermore, we show that this instability competes with the Gregory-Laflamme instability and can branch into multiple steady-state solutions.
JOURNAL OF HIGH ENERGY PHYSICS
(2023)
Article
Physics, Particles & Fields
Gary T. Horowitz, Maciej Kolanowski, Jorge E. Santos
Summary: In holography, the IR behavior of a quantum system at nonzero density is described by the near horizon geometry of an extremal charged black hole. It is commonly believed that for systems on S-3, this near horizon geometry is AdS(2) x S-3. However, we show that this is not the case and propose a new near horizon geometry that is stable under certain perturbations and develops in nonextremal, SO(3)-invariant charged black holes. Our findings suggest that the previously believed stable IR fixed point is not accurate.
JOURNAL OF HIGH ENERGY PHYSICS
(2023)
Article
Physics, Particles & Fields
Oscar J. C. Dias, Prahar Mitra, Jorge E. Santos
Summary: We systematically search for supergravity solutions that are dual to thermal states in N = 4 SYM at finite chemical potential via the AdS(5)/CFT4 correspondence. These solutions dominate the microcanonical ensemble and are required for reproducing the microscopic entropy of AdS black holes. Using analytical and numerical methods, we construct and study static charged hairy solitonic and black hole solutions with global AdS(5) asymptotics. Our findings provide a good understanding of the full phase space of SYM thermal states with three arbitrary chemical potentials, along with the known phases of the truncation with three equal charges.
JOURNAL OF HIGH ENERGY PHYSICS
(2023)
Article
Physics, Particles & Fields
Oscar J. C. Dias, Takaaki Ishii, Keiju Murata, Jorge E. Santos, Benson Way
Summary: We construct a cohomogeneity-1 helical black string in six-dimensional Einstein gravity originating from the superradiant instability of the Myers-Perry black string. The helical black string possesses helical isometries generated by linear combinations of time translation, shifts along the string, and rotation, which are individually broken by the superradiant instability. Despite the absence of momentum in the string direction, the helical black string exhibits nonzero horizon velocity.
JOURNAL OF HIGH ENERGY PHYSICS
(2023)
Article
Physics, Particles & Fields
Oscar J. C. Dias, Takaaki Ishii, Keiju Murata, Jorge E. E. Santos, Benson Way
Summary: We introduce novel black strings, termed black resonator strings, with a helical Killing vector field that do not possess the symmetries of time-translation invariance, axisymmetry, or translational invariance in the string direction. These solutions originate from the superradiant instability of D=6 Myers-Perry black strings with equal angular momenta. In addition, we construct horizonless Kaluza-Klein geons that share the symmetries of black resonator strings but are separate solutions from the black resonator strings.
JOURNAL OF HIGH ENERGY PHYSICS
(2023)
Article
Astronomy & Astrophysics
Oscar J. C. Dias, Mahdi Godazgar, Jorge E. Santos, Gregorio Carullo, Walter Del Pozzo, Danny Laghi
Summary: The study focused on gravitational and electromagnetic perturbations of the Kerr-Newman black hole, identifying unique phenomena in the Quasinormal Mode families. The derived QNM spectra are crucial for understanding gravitational emissions in astrophysical environments and extracting observational implications of new physics scenarios.
Article
Astronomy & Astrophysics
Gregorio Carullo, Danny Laghi, Nathan K. Johnson-McDaniel, Walter Del Pozzo, Mahdi Godazgar, Jorge E. Santos, Oscar J. C. Dias
Summary: We constructed a template to study the postmerger phase of a binary black hole coalescence with a remnant U(1) charge. Our analysis showed that it is difficult to distinguish between charged and uncharged hypotheses based on purely postmerger analysis. However, by analyzing the full signal, we were able to obtain upper limits on the black hole charge-to-mass ratio. This model can provide a robust measurement of the charge-to-mass ratio for certain values when simulating a loud signal observed by the LIGO-Virgo network.