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, 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, Multidisciplinary
Askar Ali, Khalid Saifullah
Summary: The study investigates a new model of nonlinear Maxwell electrodynamics as a source of gravitational field, and examines the properties of black holes in four-dimensional Einstein-Gauss-Bonnet gravity with a novel metric function. The calculations of basic thermodynamic quantities and the investigation of thermodynamic stability and thermal phase transitions are carried out for the new black hole solution.
Article
Physics, Particles & Fields
Yi-Li Wang, Xian-Hui Ge
Summary: This paper investigates the Einstein-Maxwell-Gauss-Bonnet-axion theory in 4-dimensional spacetime through a Kaluza-Klein-like process. By obtaining the dyonic black hole solution coupled with higher derivative terms, the behavior of shear viscosity to entropy density ratio at different temperatures is studied. It is found that the ratio of uncharged black holes violates a specific bound at low temperatures, and the main feature of this ratio remains almost unchanged in 4 dimensions.
EUROPEAN PHYSICAL JOURNAL C
(2021)
Article
Astronomy & Astrophysics
M. Bousder, M. Bennai
Summary: This study investigates the charge of the 4D-Einstein-Gauss-Bonnet black hole by examining the charge of a particle-antiparticle pair at r(-) and r(+) horizons, showing the existence of two types of Schwarzschild black holes and quantified values for the Einstein-Gauss-Bonnet black hole charge. The study also reveals the Hawking-Bekenstein formula with two logarithmic corrections, where the second correction depends on the cosmological constant and the black hole charge. Finally, the thermodynamics of the EGB-AdS black hole is explored.
Article
Astronomy & Astrophysics
Sreejith Nair, Vardarajan Suneeta
Summary: This study investigates the black hole black string phase transition in Einstein-Gauss-Bonnet gravity in the large dimension limit. The results suggest that the geometry at the merger point may not necessarily approach a black hole as the dimensions increase.
Article
Astronomy & Astrophysics
Milko Estrada, Rodrigo Aros
Summary: We present a new regular black hole solution with localized sources of matter in Einstein Gauss-Bonnet gravity. The necessary constraints for the solution to be regular are determined, which could be used as a recipe for constructing new solutions. The first law of thermodynamics is rewritten for EGB, leading to correct values of entropy and volume. The extremal black hole size diminishes for higher dimensions and the appearance of quantum effects may be related to the contraction of the horizon radius close to the Planck length. Phase transitions are induced by matter fields, resulting in two regions of stability.
Article
Astronomy & Astrophysics
Ryotaku Suzuki, Shinya Tomizawa
Summary: This study applies the large D approach to construct equally rotating black hole solutions in odd dimensions, providing the first example of analytic solutions for not-slowly rotating black holes. The physical aspects of the next-to-leading-order solutions in the 1/D expansion, such as thermodynamics and the phase diagram, are discussed.
Article
Astronomy & Astrophysics
Kalin Staykov, Daniela D. Doneva
Summary: A new nonlinear mechanism for black hole scalarization, different from the standard spontaneous scalarization, is studied in multiscalar Gauss-Bonnet gravity. Numerical calculations demonstrate the existence of scalarized black holes for different coupling functions and scalar field target spaces.
Article
Physics, Multidisciplinary
Dharm Veer Singh, Benoy Kumar Singh, Sudhaker Upadhyay
Summary: The study derives an exact black hole solution for Einstein-Gauss-Bonnet gravity with Yang-Mills field in 4D AdS spacetime, and investigates its thermodynamic properties to calculate black hole mass, temperature, entropy, and heat capacity. The presence of Yang-Mills field modifies the thermodynamic quantities, but the entropy remains unaffected by the Yang-Mills charge. The solution exhibits P-v criticality and belongs to the universality class of Van der Waals fluid.
Article
Astronomy & Astrophysics
Meng-Yun Lai, De-Cheng Zou, Rui-Hong Yue, Yun Soo Myung
Summary: This paper discusses the fully nonlinear mechanism for the formation of scalarized rotating black holes in Einstein-scalar-Gauss-Bonnet gravity. Multiple scalarized branches of black hole solutions are obtained using the pseudospectral method, and the phase transition between Kerr black holes and scalarized black holes is investigated.
Article
Physics, Nuclear
Kimet Jusufi
Summary: Using a modified expression for the electric potential in the context of T-duality, an exact charged solution is obtained within the 4D Einstein-Gauss-Bonnet (4D EGB) theory of gravity in the presence of a cosmological constant. The solution is also shown to exist in the regularized 4D EGB theory, and a correspondence between the black hole solution in the 4D EGB theory and the solution in the non-relativistic Horava-Lifshitz theory is pointed out. The black hole solution is regular and singularity-free, and a class of well known solutions in the literature is derived as a special case.
Article
Astronomy & Astrophysics
Uma Papnoi, Farruh Atamurotov
Summary: A charged rotating black hole was constructed in 4D Einstein-Gauss-Bonnet gravity from a charged black hole in 4D EGB gravity using complex coordinate transformations suggested by Newman-Janis. The null geodesics were studied to investigate the shadow shape cast by a rotating charged black hole in 4D EGB gravity, with analysis on the influence of Gauss-Bonnet term and black hole charge on horizon, shadow, effective potential, and energy emission rate. The Gauss-Bonnet parameter was found to have an impact on the shape and size of the shadow, as well as on the effective potential, horizon, and energy emission rate.
PHYSICS OF THE DARK UNIVERSE
(2022)
Article
Astronomy & Astrophysics
I. . D. D. Carvalho, G. Alencar, C. R. Muniz
Summary: This paper investigates Einstein-Gauss-Bonnet (EGB) black holes surrounded by phenomenological distributions of dark matter halos. The main findings include obtaining analytical solutions for the metric and all thermodynamic quantities, exploring the existence of remnants when the black hole temperature vanishes, identifying ergospheres for the stationary solutions, and discovering phase transitions through the analysis of heat capacity and Gibbs free energy. © 2023 Elsevier B.V. All rights reserved.
PHYSICS OF THE DARK UNIVERSE
(2023)
Article
Astronomy & Astrophysics
Naresh Dadhich, Sanjar Shaymatov
Summary: In this paper, circular orbits around higher dimensional rotating black holes are studied. It is found that there are no stable circular orbits around Myers-Perry black holes, while bound and stable circular orbits do exist for pure GB/Lovelock black holes. This property serves as a nice discriminator between Myers-Perry and pure GB/Lovelock rotating black holes.
PHYSICS OF THE DARK UNIVERSE
(2022)
Article
Physics, Particles & Fields
Giorgos Anastasiou, Ignacio J. Araya, Rodrigo Olea
Summary: This study extends Maldacena's argument to six-dimensional manifolds, showing that 6D Conformal Gravity can yield an Einstein gravity sector. Through the use of generalized Neumann boundary conditions, the Conformal Gravity action is reduced to the renormalized Einstein-AdS action. The equivalence between Conformal and Einstein gravity simplifies the Einstein solutions of 6D Critical Gravity at the bicritical point.
JOURNAL OF HIGH ENERGY PHYSICS
(2021)
Article
Physics, Particles & Fields
L. Andrianopoli, B. L. Cerchiai, R. Matrecano, O. Miskovic, R. Noris, R. Olea, L. Ravera, M. Trigiante
Summary: This paper extensively explores the holographic framework of an N=2 pure AdS supergravity model in four dimensions, focusing on the asymptotic symmetries at the boundary and their related properties. The consistency of the holographic setup requires the vanishing of super-AdS curvatures at the boundary, resulting in special properties for the boundary of the gravitational theory.
JOURNAL OF HIGH ENERGY PHYSICS
(2021)
Article
Astronomy & Astrophysics
Pablo Guilleminot, Felix-Louis Julie, Nelson Merino, Rodrigo Olea
Summary: Based on the insights gained by various authors on the structure of Einstein-Hilbert, Gauss-Bonnet, and Lovelock gravity Lagrangians, this paper demonstrates how to derive their first-order generalized 'Arnowitt-Deser-Misner' Lagrangian and associated Hamiltonian in a simple manner. The derivation begins with the Lovelock Lagrangian supplemented with the Myers boundary term, ensuring a Dirichlet variational principle with a specific surface term. The first-order Lagrangian density is obtained by integrating the canonical momentum over the metric derivative normal to the boundary or by converting the Myers term into a bulk term.
CLASSICAL AND QUANTUM GRAVITY
(2021)
Article
Physics, Particles & Fields
Laura Andrianopoli, Gaston Giribet, Dario Lopez Diaz, Olivera Miskovic
Summary: We study static black hole solutions with locally spherical horizons coupled to non-Abelian fields in N = 4 Chern-Simons AdS5 supergravity, characterized by three parameters related to mass, axial torsion, and internal soliton amplitude, as well as two parameters related to gravitational hair. The solutions describe geometries that can be global AdS spaces, naked singularities, or (non-)extremal black holes. In different asymptotically AdS solutions, physical properties vary depending on whether the spatial section at radial infinity is a 3-sphere or projective 3-space. The 3-parametric solutions possess a topological structure including SU(2) solitons with nontrivial winding around the black hole horizon, with interesting features in the extremal black hole limit.
JOURNAL OF HIGH ENERGY PHYSICS
(2021)
Article
Physics, Particles & Fields
Alessio Marrani, Olivera Miskovic, Paula Quezada Leon
Summary: In this study, we investigate the phenomenon of spontaneous scalarization in electrically charged extremal black holes in D ≥ 4 spacetime dimensions. We find that scalar field condensates on the horizon only in non-flat spacetimes, with Λ not equal to 0, and when the extremal black holes have non-planar horizons k=+/-1. In order for the transition to happen, the interaction must be strong enough, and physical quantities on the horizon depend at most on the effective Higgs-Stueckelberg interaction am^2 - 2b.
JOURNAL OF HIGH ENERGY PHYSICS
(2022)
Article
Physics, Particles & Fields
Giorgos Anastasiou, Ignacio J. Araya, Rodrigo Olea
Summary: In this paper, we provide a new derivation of the Hawking mass and Willmore energy functionals by embedding Einstein-AdS gravity in Conformal Gravity. The codimension-2 conformal invariant functional L-Sigma is obtained by evaluating the four-dimensional Conformal Gravity action in a manifold with a conical defect. The results suggest a generic relation between conformal invariance and renormalization.
JOURNAL OF HIGH ENERGY PHYSICS
(2022)
Article
Physics, Particles & Fields
Giorgos Anastasiou, Ignacio J. Araya, Andres Argandona, Rodrigo Olea
Summary: In this study, we provide a covariant expression for the universal part of the holographic entanglement entropy in CFTs dual to higher curvature gravities, with up to five dimensions. We use this expression to calculate the universal coefficients of stress-tensor correlators in three-dimensional CFTs dual to Cubic Curvature Gravity. By employing gauge/gravity duality, we obtain an expression for the entanglement entropy of deformed entangling regions and extract the coefficients from the power expansion of the entropy. We compare our results obtained from different splittings with those derived from other holographic methods, finding agreement with the non-minimal splitting while ruling out the minimal splitting.
JOURNAL OF HIGH ENERGY PHYSICS
(2022)
Article
Physics, Particles & Fields
Hernan A. Gonzalez, Oriana Labrin, Olivera Miskovic
Summary: We discuss the emergence of a new symmetry generator in four-dimensional gauge theories in flat space. This generator produces an asymptotic symmetry that acts differently on asymptotic fields compared to large gauge transformations. The improved canonical generators, representing gauge and asymptotic symmetries, form a classical Kac-Moody charge algebra with a non-trivial central extension. In the case of electromagnetism, we describe the U(1) current algebra with a level proportional to the theory's coupling constant, & kappa; = 4 & pi;(2)/e(2). We also generalize these symmetries to non-Abelian theories by analyzing the evolution of Yang-Mills theory in Bondi coordinates.
JOURNAL OF HIGH ENERGY PHYSICS
(2023)
Article
Physics, Particles & Fields
Giorgos Anastasiou, Ignacio J. Araya, Cristobal Corral, Rodrigo Olea
Summary: In this article, a streamlined proof is presented to show that any Einstein-AdS space is a solution of the Lu, Pang and Pope conformal gravity theory in six dimensions. The reduction of conformal gravity into Einstein theory is demonstrated, indicating that the action of the latter can be expressed as the Einstein-Hilbert term plus the Euler topological density and an additional contribution related to the Laplacian of the bulk Weyl tensor squared. The method of embedding the Einstein theory into a Weyl-invariant purely metric theory, called Conformal Renormalization, is introduced, and its resulting action is shown to be equivalent to the one obtained by holographic renormalization. As an application, the Noether-Wald charges and thermodynamic quantities for topological black hole solutions with generic transverse section in Einstein-AdS(6) theory are computed.
JOURNAL OF HIGH ENERGY PHYSICS
(2023)
Article
Physics, Particles & Fields
Pablo Guilleminot, Nelson Merino, Rodrigo Olea
Summary: This study examines the matching conditions for a spherically symmetric thin shell in Lovelock gravity by analyzing the variation of the corresponding first-order action. It is found that by adding Myers' boundary terms to the gravitational action, the dependence on acceleration can be eliminated and the canonical momentum is included in the variation of the total action. This leads to junction conditions determined by the discontinuity of the canonical momentum along the boundary's normal evolution. Additionally, existing results on the collapse of thin shells in generic Lovelock theories are corrected due to an inaccurate analysis of the total derivative terms in the system.
EUROPEAN PHYSICAL JOURNAL C
(2022)
Article
Astronomy & Astrophysics
Olivera Miskovic, Rodrigo Olea, Yoel Parra-Cisterna
Summary: This study presents new formulas for calculating the energy of black hole solutions in the anti-de Sitter sector of gravity theory with curvature-squared terms. By adding counterterms of the extrinsic type, a finite variation of the total action is obtained, which is compatible with the boundary conditions in asymptotically AdS spaces within the framework of quadratic curvature gravity theory. The conserved charges derived from this method accurately reproduce the energy of static black holes in QCG theory, eliminating the need for background-subtraction or linearized methods.
Article
Astronomy & Astrophysics
Giorgos Anastasiou, Ignacio J. Araya, Javier Moreno, Rodrigo Olea, David Rivera-Betancour
Summary: The study presents a covariant expression for computing the renormalized holographic entanglement entropy for conformal field theories dual to quadratic curvature gravity in arbitrary dimensions. The method isolates the universal terms of the holographic entanglement entropy functional and is used to calculate the standard C-function candidate for CFTs in any dimension, as well as the type-B anomaly coefficient c for four-dimensional CFTs.
Article
Astronomy & Astrophysics
Cristobal Corral, Gaston Giribet, Rodrigo Olea
Summary: This study investigates non-Einstein Bach-flat gravitational instanton solutions as a generalization of Einstein gravity solutions to conformal gravity. These solutions exhibit different asymptotic conditions, thermodynamic properties, and geometrical characteristics, shedding light on the behaviors of conformal gravity.