Article
Physics, Multidisciplinary
Himanshu Kumar Sudhanshu, Sudhaker Upadhyay, Dharm Veer Singh, Sunil Kumar
Summary: This paper studies the effect of thermal fluctuation on the corrected entropy of a conformally dressed black hole in three dimensions. It is found that thermal fluctuation significantly affects the entropy of small black holes. The stability of the black hole under the effect of thermal fluctuation is also analyzed, and the isothermal compressibility of the black hole is studied.
INTERNATIONAL JOURNAL OF THEORETICAL PHYSICS
(2022)
Article
Physics, Particles & Fields
Fil Simovic, Danny Fusco, Robert B. Mann
Summary: The thermodynamic properties of 3+1 dimensional black holes conformally coupled to a real scalar field in asymptotically de Sitter spacetimes were investigated using a Euclidean action approach. By treating the cosmological constant as a thermodynamic pressure in the extended phase space, phase transitions resembling Hawking-Page transitions were observed in the black hole solutions, with the existence of these transitions further depending on a specific cosmic censorship bound.
JOURNAL OF HIGH ENERGY PHYSICS
(2021)
Article
Astronomy & Astrophysics
David Kokoska, Marcello Ortaggio
Summary: We investigated the complete family of Robinson-Trautman spacetimes sourced by conformally invariant nonlinear electrodynamics in D dimensions in the presence of an arbitrary cosmological constant. The solutions exist only in even dimensions, with static metrics containing dyonic black holes and different asymptotics. Time-dependent solutions may represent white hole evaporation or black hole formation in a time-reversed picture, and a quasilocal characterization of possible past horizons is discussed.
Article
Astronomy & Astrophysics
Cristian Erices, Pantelis Filis, Eleftherios Papantonopoulos
Summary: The study demonstrates the avoidance of the no-hair theorem in scalar-tensor theories with bimetric structure by introducing an electric charge, leading to black hole solutions with rich thermodynamic behavior. The interplay of stability and phase transitions between different black hole configurations resembles a solid-liquid-gas system, with an electric potential acting as pressure and a triple point where three phases coexist equally probable.
Article
Astronomy & Astrophysics
Xiao Yan Chew, Dong-han Yeom, Jose Luis Blazquez-Salcedo
Summary: This study investigates the properties of black holes and scalarons in Einstein gravity coupled to a scalar field with an asymmetric potential. The potential has been used in cosmology to describe quantum tunneling between vacuum states and contains local and global minima. The study focuses on asymptotically flat solutions and shows the existence of hairy black hole solutions that can converge to particlelike solutions in the small horizon limit. It also demonstrates the instability of both black holes and scalarons under radial perturbations.
Article
Physics, Particles & Fields
Qi Qi, Yuan Meng, Xi-Jing Wang, Xiao-Mei Kuang
Summary: This paper investigates the gravitational lensing effects in the weak and strong field limits of a static black hole with conformally coupled scalar field. The results show that the weak deflection angle can be enhanced/suppressed by the scalar hair compared to general relativity. In the strong field limit, the lensing observables are influenced by the scalar hair, and there is a degeneracy in the observables of the charged black hole with positive scalar hair and RN black hole.
EUROPEAN PHYSICAL JOURNAL C
(2023)
Article
Astronomy & Astrophysics
Eugeny Babichev, Christos Charmousis, Mokhtar Hassaine, Nicolas Lecoeur
Summary: In arbitrary higher dimension, we consider the combination of Lovelock gravity and a scalar-tensor action built out of higher order operators and Euler densities. The existence of black hole solutions interpreted as stealth configurations within Lovelock gravity theory is shown. The stealth solutions can include a time-dependent scalar field despite the underlying theory being non shift symmetric. Also, a procedure to obtain a nonconformally invariant action in even dimensions from the considered theory is presented.
Article
Astronomy & Astrophysics
K. A. Bronnikov
Summary: Simpson and Visser proposed a phenomenological way to avoid space-time singularities by replacing a parameter corresponding to singularity with a nonzero expression. This method can lead to a regular minimum beyond a black hole horizon and potentially mimic quantum gravity effects. The authors applied this method to regularize various metrics and obtained exact solutions in general relativity.
Article
Physics, Particles & Fields
Ankit Anand
Summary: In this paper, the authors investigated the space-time structure obtained by taking quotients of the AdS(4) space-time. They further considered a specific Z(2) quotient. By considering the first-order perturbation in the metric, they estimated the backreaction of the matter field on the space-time geometry. It was found that when the suitable boundary condition is chosen, the average null energy becomes negative, resulting in a traversable wormhole.
EUROPEAN PHYSICAL JOURNAL C
(2023)
Article
Astronomy & Astrophysics
Yuan-Xing Gao, Yi Xie
Summary: The study reveals that black holes in the EsGB gravity theory show unique lensing effects but currently cannot be distinguished from Schwarzschild black holes based solely on their lensing signatures.
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
Physics, Particles & Fields
Moises Bravo-Gaete, F. F. Santos
Summary: In this paper, we investigate a generalized scalar-tensor theory in four dimensions and derive a set of hairy anti-de-Sitter black hole solutions. Utilizing the Complexity equals Action conjecture, we calculate the computational complexity. Additionally, we analyze the time development of the system and calculate the shear viscosity, finding that the viscosity/entropy density ratio can violate the Kovtun-Son-Starinets bound for certain coupling function choices.
EUROPEAN PHYSICAL JOURNAL C
(2022)
Article
Astronomy & Astrophysics
Moises Bravo-Gaete, M. M. Stetsko
Summary: In this study, we investigate planar hairy black hole configurations in higher dimensions for a special subclass of the Horndeski theory. This theory is defined by two coupling functions depending on the kinetic term and enjoying shift symmetry and reflection symmetry. We obtain a set of new solutions and calculate their thermodynamic quantities, showing that for a suitable choice of the coupling functions, the shear viscosity violates the Kovtun-Son-Starinets bound.
Article
Astronomy & Astrophysics
Adolfo Cisterna, Anibal Neira-Gallegos, Julio Oliva, Scarlett C. Rebolledo-Caceres
Summary: The study demonstrates that the Plebanski-Demianski spacetime remains a solution of general relativity when supplemented with both a conformally coupled scalar theory and quadratic curvature corrections. The research also involves obtaining new hairy black hole solutions and analytically extending specific metric spacetimes to produce healthy asymptotically AdS wormhole configurations.
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
E. Ayon-Beato, F. Canfora, M. Lagos, J. Oliva, A. Vera
EUROPEAN PHYSICAL JOURNAL C
(2020)
Article
Physics, Particles & Fields
Nicolas Caceres, Jose Figueroa, Julio Oliva, Marcelo Oyarzo, Ricardo Stuardo
JOURNAL OF HIGH ENERGY PHYSICS
(2020)
Article
Physics, Particles & Fields
Fabrizio Canfora, Julio Oliva, Marcelo Oyarzo
Summary: In this paper, we revisit the problem of finding BPS solutions in N = 4 SU (2) x SU (2) gauged supergravity. We report a new supersymmetric solution in the Abelian sector and a new solution whose supersymmetric nature was overlooked in the previous literature. Moving to the non-Abelian sector, we construct electric-meronic and double-meron solutions, which lead to singular 1/4 BPS configurations. We also modify the self-interaction of the scalar and construct exact black holes with interesting causal structures and asymptotic behavior.
JOURNAL OF HIGH ENERGY PHYSICS
(2022)
Article
Physics, Particles & Fields
Monserrat Aguayo, Ankai Hernandez, Jose Mena, Julio Oliva, Marcelo Oyarzo
Summary: In this paper, a new family of black holes and solitons is identified, which allows for exact integration of scalar probes even with a non-minimal coupling with the Ricci scalar. The discrete modes on these geometries are independent of the radius of the black hole and can be integrated using hypergeometric functions to obtain exact expressions for the frequencies.
JOURNAL OF HIGH ENERGY PHYSICS
(2022)
Article
Astronomy & Astrophysics
Jose Barrientos, Adolfo Cisterna, David Kubiznak, Julio Oliva
Summary: This paper constructs accelerated black holes in non-linear electrodynamics and studies their thermodynamics, providing new insights into the study of radiative spacetimes in the non-linear electromagnetic regime.
Article
Astronomy & Astrophysics
Andres Anabalon, Patrick Concha, Julio Oliva, Constanza Quijada, Evelyn Rodriguez
Summary: This work investigates the phase transitions between the planar charged AdS black hole and the planar charged soliton. The planar soliton is obtained by analytically continuing the charged black hole metric, including the analytical continuation of the electric charge. It is shown that there are phase transitions between the two solutions depending on the electric potential, magnetic flux, and temperature.
Article
Astronomy & Astrophysics
Fabrizio Canfora, Alex Giacomini, Nicolas Grandi, Julio Oliva, Aldo Vera
Summary: We present a precise time-dependent solution for a charged scalar field on a two-dimensional cylinder, which represents a long-standing excitation on a S-wave superconducting state propagated along a nanotube constructed out of twisted bilayer graphene. The solution has a topological charge characterized by an integer number that counts the winding of the Higgs phase around the cylinder. The resulting electric current generates its own electromagnetic field in a self-consistent way, without the need for external fields to sustain it.
Article
Astronomy & Astrophysics
Cristobal Corral, Daniel Flores-Alfonso, Gaston Giribet, Julio Oliva
Summary: This paper discusses the higher-dimensional generalizations of the Eguchi-Hanson gravitational instanton in the presence of higher-curvature deformations of general relativity. It analyzes different aspects of these solutions, including the regularization of the on-shell Euclidean action by means of the addition of topological invariants, and the explicit construction of Eguchi-Hanson type solutions with higher-curvature corrections to the gravity action.
Article
Astronomy & Astrophysics
Moises Bravo-Gaete, Luis Guajardo, Julio Oliva
Summary: In this work, we investigate a well-defined theory that allows a healthy limit of the Einstein-Gauss-Bonnet combination. We construct exact hairy black hole solutions in the presence of matter sources and find a region in parameter space where these black holes have well-defined, nonvanishing, finite thermodynamic quantities, despite the relaxed asymptotic approach to planar AdS. We also test the stability of these solutions under thermal and electrical fluctuations and demonstrate the satisfaction of a Smarr relation.
Article
Physics, Particles & Fields
M. R. Setare, Julio Oliva, S. N. Sajadi
Summary: In this work, the near horizon and asymptotic symmetries of static and rotating hairy-AdS black holes were investigated within the framework of general minimal massive gravity. The energy, angular momentum, and entropy of the solutions were obtained and shown to be consistent with the first law of black hole thermodynamics. Additionally, near horizon conserved charges and their algebra were found by considering the near horizon geometry of the black hole, with conserved charges expressed in terms of zero modes through Fourier modes.
EUROPEAN PHYSICAL JOURNAL C
(2022)
Article
Astronomy & Astrophysics
Fabrizio Canfora, Adolfo Cisterna, Sebastian Fuenzalida, Carla Henriquez-Baez, Julio Oliva
Summary: In this work, it was demonstrated that Einstein gravity in four dimensions can be consistently obtained through the compactification of a higher curvature Lovelock theory in dimension D = 4 + p (p >= 1). The compactification is performed without the need for fine tuning between coupling constants. This process involves dressing the internal manifold with suitable forms and constructing various black string/p-branes solutions.
Article
Astronomy & Astrophysics
Gaston Giribet, Julio Oliva, Ricardo Stuardo
Summary: The study discusses a solvable irrelevant deformation of string theory on AdS(3) with NS-NS fluxes, which has a geometric interpretation of transitioning between anti-de Sitter (AdS(3)) and a linear dilaton spacetime. The main focus is on computing correlation functions and the spectrum of the deformed world sheet theory, as well as extending this type of current-current deformation to other conformal models.
Article
Astronomy & Astrophysics
Adolfo Cisterna, Anibal Neira-Gallegos, Julio Oliva, Scarlett C. Rebolledo-Caceres
Summary: The study demonstrates that the Plebanski-Demianski spacetime remains a solution of general relativity when supplemented with both a conformally coupled scalar theory and quadratic curvature corrections. The research also involves obtaining new hairy black hole solutions and analytically extending specific metric spacetimes to produce healthy asymptotically AdS wormhole configurations.
Article
Astronomy & Astrophysics
Fabrizio Canfora, Adolfo Cisterna, Diego Hidalgo, Julio Oliva
Summary: New exact solutions of the Abelian-Higgs model coupled to general relativity with nonvanishing superconducting current are found, corresponding to different types of waves and spaces. The geometry of the superconducting current is determined by the solutions of the two-dimensional Lionville equation, confining the electromagnetic field within a bounded region in the surfaces transverse to the current.
Article
Astronomy & Astrophysics
Octavio Fierro, Nicolas Mora, Julio Oliva
Summary: This paper discusses the characteristics of quartic quasitopological gravity theories in five dimensions and the method to construct slowly rotating black holes in these theories. By restriction that the off-diagonal components of the metric in the quartic theories are second-order equations, the degeneracy of the theories can be partially removed. Furthermore, it is shown that in order to obtain rotating black hole solutions in quasitopological gravity, one must go beyond the Kerr-Schild Ansatz.
