Article
Astronomy & Astrophysics
Peter Taylor, Cormac Breen
Summary: This study focuses on the quantum scalar field on the classical background of an asymptotically anti-de Sitter black hole and the backreaction the field's stress-energy tensor induces on the black hole geometry. By using simple analytical approximations to calculate the stress-energy tensor, reasonable approximations to the first-order quantum backreaction on the geometry of asymptotically anti-de Sitter black holes are provided.
Article
Astronomy & Astrophysics
M. A. Cuyubamba
Summary: A regularized four-dimensional Einstein-Gauss-Bonnet model has been proposed, bypassing the Lovelock theorem. The study shows that the black-hole configurations in different spacetimes have stable parameter regions but also exhibit some instabilities. Additionally, instabilities due to positive cosmological constant are explored in the research.
PHYSICS OF THE DARK UNIVERSE
(2021)
Article
Astronomy & Astrophysics
Mengjie Wang, Zhou Chen, Xin Tong, Qiyuan Pan, Jiliang Jing
Summary: By studying the Maxwell quasinormal spectrum on asymptotically anti-de Sitter black holes, we found that the spectrum bifurcates as the black hole radius increases, termed the mode split effect. Additionally, at a fixed black hole radius, increasing the monopole parameter may trigger or terminate this mode split effect.
Article
Astronomy & Astrophysics
M. Afif Ismail, Yi-Zen Chu, Yen-Wei Liu
Summary: The study reveals that the propagation of massless scalar fields in asymptotically de Sitter spacetimes exhibits both linear and nonlinear tail-induced memories. Additionally, for sufficiently late retarded times, the monopole portion of the scalar signal measured at null infinity is amplified relative to its timelike infinity counterpart, due to nonlinear interactions with the gravitational field at first order in the central mass M.
Article
Physics, Multidisciplinary
Anxo Biasi, Oleg Evnin, Spyros Sypsas
Summary: Cosmological acceleration is difficult to explain in theories involving supergravity and superstrings, but it is possible in theories with regular black holes. By placing this scenario in a global antide Sitter background, the formation of de Sitter bubbles can be enhanced, potentially leading to the creation of multiple accelerating universes. Numerical work in a two-dimensional dilaton-gravity model supports this idea.
PHYSICAL REVIEW LETTERS
(2022)
Article
Physics, Mathematical
Christyan C. de Oliveira, Ricardo A. Mosna, Joao Paulo M. Pitelli
Summary: In this paper, we revisit the propagation of classical scalar fields in an asymptotically anti-de Sitter spacetime. The lack of global hyperbolicity in the underlying background leads to an ambiguity in the dynamical evolution of wave equation solutions, requiring the specification of additional boundary conditions at the conformal infinity. We demonstrate that the only boundary conditions compatible with the hypothesis of the system being isolated, as defined by the (improved) energy-momentum tensor, are of Dirichlet and Neumann types.
JOURNAL OF MATHEMATICAL PHYSICS
(2022)
Article
Astronomy & Astrophysics
Cheng-Yong Zhang, Peng Liu, Yun-Qi Liu, Chao Niu, Bin Wang
Summary: The study focuses on the fully nonlinear dynamics of spherically symmetric black hole spontaneous scalarization in Einstein-Maxwell-scalar theory. It is found that by adjusting the coupling function and black hole charge, the development and stabilization of hairy black holes can be influenced.
Article
Astronomy & Astrophysics
Sumanta Chakraborty, S. K. Jahanur Hoque, Roberto Oliveri
Summary: The study provides a prescription to compute the gravitational multipole moments of compact objects in asymptotically de Sitter spacetimes. The prescription is based on a recent definition of gravitational multipole moments and is applied to the Kerr-de Sitter black hole to calculate its multipole structure. The results recover the Geroch-Hansen moments of the Kerr black hole when the cosmological constant vanishes.
Article
Astronomy & Astrophysics
Cheng-Yong Zhang, Peng Liu, Yunqi Liu, Chao Niu, Bin Wang
Summary: The study focused on the nonlinear evolution of spherically symmetric charged black holes in asymptotic anti-de Sitter spacetime under a small neutral scalar field perturbation in Einstein-Maxwell-dilaton theory with a coupling function f(phi) = e(-b phi). The nonminimal coupling between scalar and Maxwell fields allows energy transmission, acting as both attractive and repulsive forces for the scalar. The irreducible mass of the black hole increases abruptly at initial times, saturating to a final value exponentially, with the saturating rate being twice the decaying rate of the dominant mode of the scalar.
Article
Astronomy & Astrophysics
Takuya Katagiri, Masashi Kimura
Summary: In this paper, we discuss the dynamics of massive Klein-Gordon fields in two-dimensional anti-de Sitter spacetimes, focusing on the conserved quantities and nonmodal instability known as the Aretakis constants and instability. We reveal the geometrical interpretation of the Aretakis constants and instability in a parallel-transported frame along a null geodesic, showing that the instability arises from singular behaviors of higher-order covariant derivatives of the fields on the entire AdS infinity. Additionally, the Aretakis constants are shown to be related to conformal Killing tensors and can be derived from ladder operators based on spacetime conformal symmetry.
Article
Mathematics, Applied
Gustav Holzegel, Arick Shao
Summary: In this paper, the authors investigate the correspondence between vacuum asymptotically anti-de Sitter spacetimes and their conformal boundary data. They establish a link between the coefficients in a Fefferman-Graham expansion of the metric and the conformal boundary, under certain conditions. The proof relies on a calculus of vertical tensor-fields, a system of transport and wave equations, and Carleman estimates for tensorial wave equations near the conformal boundary.
ARCHIVE FOR RATIONAL MECHANICS AND ANALYSIS
(2023)
Article
Mathematics, Applied
Gustav Holzegel, Arick Shao
Summary: In this paper, a correspondence is established between vacuum asymptotically anti-de Sitter spacetimes and their conformal boundary data near the boundary. It is proven that the coefficients of the metric's expansion uniquely determine the metric near a given domain on the boundary, under a certain convexity condition. The proof relies on a calculus of vertical tensor-fields, a system of transport and wave equations, and recently established Carleman estimates for tensorial wave equations.
ARCHIVE FOR RATIONAL MECHANICS AND ANALYSIS
(2023)
Article
Astronomy & Astrophysics
Arick Shao
Summary: The study focuses on the geometry of a general class of vacuum asymptotically anti-de Sitter spacetimes near the conformal boundary, with results to be applied toward proving symmetry extension and gravity-boundary correspondence theorems for such spacetimes in future publications.
CLASSICAL AND QUANTUM GRAVITY
(2021)
Article
Physics, Mathematical
Athanasios Chatzikaleas, Arick Shao
Summary: We reconsider the unique continuation property for a general class of tensorial Klein-Gordon equations on asymptotically anti-de-Sitter spacetimes. We generalize previous results by replacing the geometric assumption on the conformal boundary with a more general and gauge invariant criterion, applying the new unique continuation property to a larger class of domains, and connecting the failure of our criterion to the existence of certain null geodesics near the conformal boundary.
COMMUNICATIONS IN MATHEMATICAL PHYSICS
(2022)
Article
Mathematics
Claudio Dappiaggi, Alessio Marta
Summary: In this paper, the authors consider the Klein-Gordon equation on an asymptotically anti-de Sitter spacetime with Robin boundary conditions, proving a propagation of singularities theorem. They also generalize this result to a more general class of boundary conditions implemented on the conformal boundary and prove a propagation of singularity theorem along generalized broken bicharacteristics.
MATHEMATISCHE NACHRICHTEN
(2022)
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
Astronomy & Astrophysics
Filippo Camilloni, Oscar J. C. Dias, Gianluca Grignani, Troels Harmark, Roberto Oliveri, Marta Orselli, Andrea Placidi, Jorge E. Santos
Summary: This study focuses on the BZ split-monopole model, resolving issues around outer light surface behavior, presenting a new perturbative approach extended to higher orders, improving consistency with numerical simulations, and proposing a novel numerical procedure.
JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS
(2022)
Article
Physics, Particles & Fields
Alex Davey, Oscar J. C. Dias, Paul Rodgers, Jorge E. Santos
Summary: This article discusses the violations and respects of Strong Cosmic Censorship (SCC) in different types of black holes in various spacetime dimensions. It also explores the characteristics of the scalar field quasinormal mode spectra related to SCC.
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
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
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.
