Spinning a charged dilaton black hole
Shiraishi, Kiyoshi
2015-01-01
A charged dilaton black hole which possesses infinitesimal angular momentum is studied. We find that the gyromagnetic ratio of the dilaton black hole depends not only on the parameter which appears in the interaction between the dilaton and the electric field but also nonlinearly on the ratio of the charge to the mass of the black hole. The moment of inertia for the charged dilaton hole in the limit of infinitesimal angular momentum is also calculated.
Dyonic black holes and dilaton charge in string theory
Goulart, Prieslei
2016-01-01
We give the most general four-dimensional non-extremal dyonic black solution for Einstein-Maxwell-dilaton theory in absence of a scalar potential. The solution is written in terms of five independent parameters: the electic charge $Q$, the magnetic charge $P$, the value of the dilaton at infinity $\\phi_{0}$, and two integration constants, $r_{1}$ and $r_{2}$. The dilaton charge is given in terms of all of these parameters. Particular choices of the integration constants allow us to recover the other known black hole solutions found before. We discuss the thermodynamical properties of these black holes for the non-extremal and extremal cases. From the solution for the dilaton it is straightforward to provide an answer to why is $\\phi_{H, \\text{extreme}}$ independent of $\\phi_{0}$ and to why $\\phi_{H, \\text{extreme}}=\\phi_{0}$ when the dilaton charge is zero.
Effect of Thermal Fluctuations on a Charged Dilatonic Black Saturn
Pourhassan, Behnam
2016-01-01
In this paper, we will analyze the effect of thermal fluctuations on the thermodynamics of a charged dilatonic black Saturn. These thermal fluctuations will correct the thermodynamics of the charged dilatonic black Saturn. We will analyze the corrections to the thermodynamics of this system by first relating the fluctuations in the entropy to the fluctuations in the energy. Then, we will use the relation between entropy and a conformal field theory to analyze the fluctuations in the entropy. We will demonstrate that similar physical results are obtained from both these approaches. We will also study the effect of thermal fluctuations on the phase transition in this charged dilatonic black Saturn.
Effect of thermal fluctuations on a charged dilatonic black Saturn
Directory of Open Access Journals (Sweden)
Behnam Pourhassan
2016-04-01
Full Text Available In this paper, we will analyze the effect of thermal fluctuations on the thermodynamics of a charged dilatonic black Saturn. These thermal fluctuations will correct the thermodynamics of the charged dilatonic black Saturn. We will analyze the corrections to the thermodynamics of this system by first relating the fluctuations in the entropy to the fluctuations in the energy. Then, we will use the relation between entropy and a conformal field theory to analyze the fluctuations in the entropy. We will demonstrate that similar physical results are obtained from both these approaches. We will also study the effect of thermal fluctuations on the phase transition in this charged dilatonic black Saturn.
Charged dilatonic black holes in gravity's rainbow
Energy Technology Data Exchange (ETDEWEB)
Hendi, S.H. [Shiraz University, Physics Department and Biruni Observatory, College of Sciences, Shiraz (Iran, Islamic Republic of); Research Institute for Astronomy and Astrophysics of Maragha (RIAAM), Maragha (Iran, Islamic Republic of); Faizal, Mir [University of Waterloo, Department of Physics and Astronomy, Waterloo, ON (Canada); Panah, B.E. [Shiraz University, Physics Department and Biruni Observatory, College of Sciences, Shiraz (Iran, Islamic Republic of); Panahiyan, S. [Shiraz University, Physics Department and Biruni Observatory, College of Sciences, Shiraz (Iran, Islamic Republic of); Shahid Beheshti University, Physics Department, Tehran (Iran, Islamic Republic of)
2016-05-15
In this paper, we present charged dilatonic black holes in gravity's rainbow. We study the geometric and thermodynamic properties of black hole solutions. We also investigate the effects of rainbow functions on different thermodynamic quantities for these charged black holes in dilatonic gravity's rainbow. Then we demonstrate that the first law of thermodynamics is valid for these solutions. After that, we investigate thermal stability of the solutions using the canonical ensemble and analyze the effects of different rainbow functions on the thermal stability. In addition, we present some arguments regarding the bound and phase transition points in context of geometrical thermodynamics. We also study the phase transition in extended phase space in which the cosmological constant is treated as the thermodynamic pressure. Finally, we use another approach to calculate and demonstrate that the obtained critical points in extended phase space represent a second order phase transition for these black holes. (orig.)
Charged rotating dilaton black holes with Kaluza-Klein asymptotics
Knoll, Christian; Nedkova, Petya
2016-03-01
We construct a class of stationary and axisymmetric solutions to the five-dimensional Einstein-Maxwell-dilaton gravity, which describe configurations of charged rotating black objects with Kaluza-Klein asymptotics. The solutions are constructed by uplifting a vacuum seed solution to six dimensions, performing a boost and a subsequent circle reduction. We investigate the physical properties of the charged solutions and obtain their general relations to the properties of the vacuum seed. We also derive the gyromagnetic ratio and the Smarr-like relations. As particular cases, we study three solutions, which describe a charged rotating black string, a charged rotating black ring on Kaluza-Klein bubbles, and a superposition of two black holes and a Kaluza-Klein bubble.
Dirac quasinormal modes of two-dimensional charged dilatonic black holes
Energy Technology Data Exchange (ETDEWEB)
Becar, Ramon [Universidad Catolica de Temuco, Departamento de Ciencias Matematicas y Fisicas, Temuco (Chile); Gonzalez, P.A. [Universidad Diego Portales, Facultad de Ingenieria, Santiago (Chile); Vasquez, Yerko [Universidad de La Serena, Departamento de Fisica, Facultad de Ciencias, La Serena (Chile)
2014-06-15
We study charged fermionic perturbations in the background of two-dimensional charged dilatonic black holes, and we present the exact Dirac quasinormal modes. Also, we study the stability of these black holes under charged fermionic perturbations. (orig.)
Timelike geodesics around a charged spherically symmetric dilaton black hole
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Blaga C.
2015-01-01
Full Text Available In this paper we study the timelike geodesics around a spherically symmetric charged dilaton black hole. The trajectories around the black hole are classified using the effective potential of a free test particle. This qualitative approach enables us to determine the type of orbit described by test particle without solving the equations of motion, if the parameters of the black hole and the particle are known. The connections between these parameters and the type of orbit described by the particle are obtained. To visualize the orbits we solve numerically the equation of motion for different values of parameters envolved in our analysis. The effective potential of a free test particle looks different for a non-extremal and an extremal black hole, therefore we have examined separately these two types of black holes.
Energy Technology Data Exchange (ETDEWEB)
Becar, Ramon [Universidad Catolica de Temuco, Departamento de Ciencias Matematicas y Fisicas, Temuco (Chile); Gonzalez, P.A. [Universidad Diego Portales, Facultad de Ingenieria, Santiago (Chile); Saavedra, Joel [Pontificia Universidad Catolica de Valparaiso, Instituto de Fisica, Valparaiso (Chile); Vasquez, Yerko [Universidad de La Serena, Departamento de Fisica, Facultad de Ciencias, La Serena (Chile)
2015-02-01
We study massive charged fermionic perturbations in the background of a charged two-dimensional dilatonic black hole, and we solve the Dirac equation analytically. Then we compute the reflection and transmission coefficients and the absorption cross section for massive charged fermionic fields, and we show that the absorption cross section vanishes at the low- and high-frequency limits. However, there is a range of frequencies where the absorption cross section is not null. Furthermore, we study the effect of the mass and electric charge of the fermionic field over the absorption cross section. (orig.)
On the critical phenomena and thermodynamics of charged topological dilaton AdS black holes
Zhao, Ren; Ma, Meng-Sen; Zhang, Li-Chun
2013-01-01
In this paper, we study the phase structure and equilibrium state space geometry of charged topological dilaton black holes in $(n+1)$-dimensional anti-de Sitter spacetime. By considering the pairs of parameters $(P\\sim V)$ and $(Q\\sim U)$ as variables, we analyze the phase structure and critical phenomena of black holes and discuss the relation between the two kinds of critical phenomena. We find that the phase structures and critical phenomena drastically depend on the cosmological constant $l$ (or the static electric charge $Q$ of the black holes), dimensionality $n$ and dilaton field $\\Phi $.
Abbott-Deser-Tekin Charge of Dilaton Black Holes with Squashed Horizons
Institute of Scientific and Technical Information of China (English)
Jun-Jin Peng; Wen-Chang Xiang; Shao-Hong Cai
2016-01-01
We consider the conserved charge of static black holes with squashed horizons in the Einstein-Maxwell-dilaton theory via both the Abbott-Deser-Tekin (ADT) method and its off-shell generalization.We first make use of the original ADT method to compute the mass of the dilaton squashed black holes in terms of three different reference spacetimes,which are the asymptotic geometry,the fiat background and the spacetime of the KaluzaKlein monopole with boundary matched to the original metric,respectively.Each mass satisfies the first law of black hole thermodynamics,although the mass computed on the basis of the boundary matching the KaluzaKlein monopole is different from that of the other two reference spacetimes.Then the mass of the black holes is evaluated through the off-shell generalized ADT method.
Charged, rotating black objects in Einstein-Maxwell-dilaton theory in $D\\ge 5$
Kleihaus, Burkhard; Radu, Eugen
2016-01-01
We show that the general framework proposed in arXiv:1410.0581 for the study of asymptotically flat vacuum black objects with $k+1$ equal magnitude angular momenta in $D\\geq 5$ spacetime dimensions (with $0\\leq k\\leq \\big[\\frac{D-5}{2} \\big]$) can be extended to the case of Einstein-Maxwell-dilaton (EMd) theory. This framework can describe black holes with spherical horizon topology, the simplest solutions corresponding to a class of electrically charged (dilatonic) Myers-Perry black holes. Balanced charged black objects with $ S^{n+1} \\times S^{2k+1}$ horizon topology can also be studied (with $D=2k+n+4$). Black rings correspond to the case $k=0$, while the solutions with $k>0$ are black ringoids. The basic properties of EMd solutions are discussed for the special case of a Kaluza-Klein value of the dilaton coupling constant. We argue that all features of these solutions can be derived from those of the vacuum seed configurations.
Charged, Rotating Black Objects in Einstein–Maxwell-Dilaton Theory in D ≥ 5
Directory of Open Access Journals (Sweden)
Burkhard Kleihaus
2016-05-01
Full Text Available We show that the general framework proposed by Kleihaus et al. (2015 for the study of asymptotically flat vacuum black objects with k + 1 equal magnitude angular momenta in D ≥ 5 spacetime dimensions (with 0 ≤ k ≤ D - 5 2 can be extended to the case of Einstein–Maxwell-dilaton (EMd theory. This framework can describe black holes with spherical horizon topology, the simplest solutions corresponding to a class of electrically charged (dilatonic Myers–Perry black holes. Balanced charged black objects with S n + 1 × S 2 k + 1 horizon topology can also be studied (with D = 2 k + n + 4 . Black rings correspond to the case k = 0 , while the solutions with k > 0 are black ringoids. The basic properties of EMd solutions are discussed for the special case of a Kaluza–Klein value of the dilaton coupling constant. We argue that all features of these solutions can be derived from those of the vacuum seed configurations.
Total Energy of Charged Black Holes in Einstein-Maxwell-Dilaton-Axion Theory
Directory of Open Access Journals (Sweden)
Murat Korunur
2012-01-01
Full Text Available We focus on the energy content (including matter and fields of the Møller energy-momentum complex in the framework of Einstein-Maxwell-Dilaton-Axion (EMDA theory using teleparallel gravity. We perform the required calculations for some specific charged black hole models, and we find that total energy distributions associated with asymptotically flat black holes are proportional to the gravitational mass. On the other hand, we see that the energy of the asymptotically nonflat black holes diverge in a limiting case.
Thermodynamics of higher dimensional topological charged AdS black holes in dilaton gravity
Hendi, S H
2010-01-01
In this paper, we study topological AdS black holes of $(n+1)$-dimensional Einstein-Maxwell-dilaton theory and investigate their properties. We use the area law, surface gravity and Gauss law interpretations to find entropy, temperature and electrical charge, respectively. We also employ the Brown and York subtraction method to calculate the quasilocal mass of the solutions. We obtain a Smarr-type formula for the mass as a function of the entropy and the charge, and compute the temperature and the electric potential through the Smarr-type formula and show that these thermodynamic quantities coincide with their values which are calculated through using the geometry. Finally, we perform a stability analysis in the canonical ensemble and investigate the effects of the dilaton field as well as other parameters on the thermal stability of the solutions. We find that there is no Hawking-Page phase transition in spite of charge provided $\\alpha \\leq \\alpha_{\\max}$.
Quasinormal Modes of Charged Dilaton Black Holes and Their Entropy Spectra
Sakalli, I.
2013-08-01
In this study, we employ the scalar perturbations of the charged dilaton black hole (CDBH) found by Chan, Horne and Mann (CHM), and described with an action which emerges in the low-energy limit of the string theory. A CDBH is neither asymptotically flat (AF) nor non-asymptotically flat (NAF) spacetime. Depending on the value of its dilaton parameter a, it has both Schwarzschild and linear dilaton black hole (LDBH) limits. We compute the complex frequencies of the quasinormal modes (QNMs) of the CDBH by considering small perturbations around its horizon. By using the highly damped QNM in the process prescribed by Maggiore, we obtain the quantum entropy and area spectra of these black holes (BHs). Although the QNM frequencies are tuned by a, we show that the quantum spectra do not depend on a, and they are equally spaced. On the other hand, the obtained value of undetermined dimensionless constant ɛ is the double of Bekenstein's result. The possible reason of this discrepancy is also discussed.
Penrose process in a charged axion-dilaton coupled black hole
Energy Technology Data Exchange (ETDEWEB)
Ganguly, Chandrima [University of Cambridge, Department of Applied Mathematics and Theoretical Physics, Cambridge (United Kingdom); SenGupta, Soumitra [Indian Association for the Cultivation of Science, Department of Theoretical Physics, Kolkata (India)
2016-04-15
Using the Newman-Janis method to construct the axion-dilaton coupled charged rotating black holes, we show that the energy extraction from such black holes via the Penrose process takes place from the axion/Kalb-Ramond field energy responsible for rendering the angular momentum to the black hole. Determining the explicit form for the Kalb-Ramond field strength, which is argued to be equivalent to spacetime torsion, we demonstrate that at the end of the energy extraction process, the spacetime becomes torsion free with a spherically symmetric non-rotating black hole remnant. In this context, applications to physical phenomena, such as the emission of neutral particles in astrophysical jets, are also discussed. It is seen that the infalling matter gains energy from the rotation of the black hole, or equivalently from the axion field, and that it is ejected as a highly collimated astrophysical jet. (orig.)
Quasinormal modes of charged dilaton black holes and their entropy spectra
Sakalli, I
2013-01-01
In this study, we employ the scalar perturbations of the charged dilaton black hole (CDBH) found by Chan, Horne and Mann (CHM), and described with an action which emerges in the low-energy limit of the string theory. A CDBH is neither asymptotically flat (AF) nor non-asymptotically flat (NAF) spacetime. Depending on the value of its dilaton parameter "a", it has both Schwarzschild and linear dilaton black hole (LDBH) limits. We compute the complex frequencies of the quasinormal modes (QNM) of the CDBH by considering small perturbations around its horizon. By using the highly damped QNMs in the process prescribed by Maggiore, we obtain the quantum entropy and area spectra of these BHs. Although the QNM frequencies are tuned by "a", we show that the quantum spectra do not depend on "a", and they are equally spaced. On the other hand, the obtained value of undetermined dimensionless constant {\\epsilon} is the double of Bekenstein's result. The possible reason of this discrepancy is also discussed.
Thermodynamics of charged rotating dilaton black branes with power-law Maxwell field
Energy Technology Data Exchange (ETDEWEB)
Zangeneh, M.K. [Shiraz University, Physics Department and Biruni Observatory, College of Sciences, Shiraz (Iran, Islamic Republic of); Sheykhi, A.; Dehghani, M.H. [Shiraz University, Physics Department and Biruni Observatory, College of Sciences, Shiraz (Iran, Islamic Republic of); Research Institute for Astronomy and Astrophysics of Maragha (RIAAM), P.O.Box 55134-441, Maragha (Iran, Islamic Republic of)
2015-10-15
In this paper, we construct a new class of charged rotating dilaton black brane solutions, with a complete set of rotation parameters, which is coupled to a nonlinear Maxwell field. The Lagrangian of the matter field has the form of the power-law Maxwell field. We study the causal structure of the spacetime and its physical properties in ample details. We also compute thermodynamic and conserved quantities of the spacetime, such as the temperature, entropy, mass, charge, and angular momentum. We find a Smarr-formula for the mass and verify the validity of the first law of thermodynamics on the black brane horizon. Finally, we investigate the thermal stability of solutions in both the canonical and the grand-canonical ensembles and disclose the effects of dilaton field and nonlinearity of the Maxwell field on the thermal stability of the solutions. We find that, for α ≤ 1, charged rotating black brane solutions are thermally stable independent of the values of the other parameters. For α > 1, the solutions can encounter an unstable phase depending on the metric parameters. (orig.)
Thermodynamics of charged rotating dilaton black branes with power-law Maxwell field
Zangeneh, M Kord; Dehghani, M H
2015-01-01
In this paper, we construct a new class of charged rotating dilaton black brane solutions, with complete set of rotation parameters, which is coupled to a nonlinear Maxwell field. The Lagrangian of the matter field has the form of the power-law Maxwell field. We study the casual structure of the spacetime and its physical properties in ample details. We also compute thermodynamic and conserved quantities of the spacetime such as the temperature, entropy, mass, charge, and angular momentum. We find a Smarr-formula for the mass and verify the validity of the first law of thermodynamics on the black brane horizon. Finally, we investigate the thermal stability of solutions in both the canonical and grand canonical ensembles and disclose the effects of the dilaton field on the thermal stability of the solutions. We find that for $\\alpha \\leq 1$, charged rotating black brane solutions are thermally stable independent of the value of the other parameters. For $\\alpha>1$, the solutions can encounter an unstable phase...
Entanglement entropy of charged dilaton-axion black hole and quantum isolated horizon
Yang, Ze-Min; Li, Xiu-Lan; Gao, Ying
2016-09-01
Based on the work of Ghosh and Perez, we calculate the statistical entropy of charged dilaton-axion black hole. In the calculations we take the integral from the position of QIH to infinity, so the obtained entropy is the entanglement entropy outside the QIH. It is shown that only if the position of QIH is properly chosen the leading term of logarithm of the number of quantum states on the QIH is equal to the leading term of the entanglement entropy outside the black hole horizon, and both are the Bekenstein-Hawking entropy. The results reveal the relation between the entanglement entropy of black hole and the logarithm of the number of quantum states.
Sheykhi, A; Zangeneh, M Kord
2016-01-01
We construct a new class of charged rotating black brane solutions in the presence of logarithmic nonlinear electrodynamics with complete set of the rotation parameters in arbitrary dimensions. The topology of the horizon of these rotating black branes are flat, while, due to the presence of the dilaton field the asymptotic behaviour of them are neither flat nor (anti)-de Sitter [(A)dS]. We investigate the physical properties of the solutions. The mass and angular momentum of the spacetime are obtained by using the counterterm method inspired by AdS/CFT correspondence. We derive temperature, electric potential and entropy associated with the horizon and check the validity of the first law of thermodynamics on the black brane horizon. We study thermal stability of the solutions in both canonical and grand canonical ensemble and disclose the effects of the rotation parameter, nonlinearity of electrodynamics and dilaton field on the thermal stability conditions. We find the solutions are thermally stable for $\\a...
Clément, G; Leygnac, C; Clement, Gerard; Gal'tsov, Dmitri; Leygnac, Cedric
2003-01-01
We present new solutions to Einstein-Maxwell-dilaton-axion (EMDA) gravity in four dimensions describing black holes which asymptote to the linear dilaton background. In the non-rotating case they can be obtained as the limiting geometry of dilaton black holes. The rotating solutions (possibly endowed with a NUT parameter) are constructed using a generating technique based on the Sp(4,R) duality of the EMDA system. In a certain limit (with no event horizon present) our rotating solutions coincide with supersymmetric Israel-Wilson-Perjes type dilaton-axion solutions. In presence of an event horizon supersymmetry is broken. The temperature of the static black holes is constant, and their mass does not depend on it, so the heat capacity is zero. We investigate geodesics and wave propagation in these spacetimes and find superradiance in the rotating case. Because of the non-asymptotically flat nature of the geometry, certain modes are reflected from infinity, in particular, all superradiant modes are confined. Thi...
Nonthermal effect of dilatonic black holes
Institute of Scientific and Technical Information of China (English)
Lü Jun-Li
2005-01-01
The quantum nonthermal effect of the spherically symmetric and rotating dilatonic black holes is studied. A crossing of the positive and negative Dirac energy of particles occurs near dilatonic black holes. We find that the dilaton coupling parameter α affects the energy of spontaneous radiant particles. The energy of particles decreases when the coupling parameter α increases.
Stringy stability of charged dilaton black holes with flat event horizon
Energy Technology Data Exchange (ETDEWEB)
Ong, Yen Chin [National Taiwan Univ., Taipei (Taiwan); Chen, Pisin [National Taiwan Univ., Taipei (Taiwan); SLAC National Accelerator Lab., Menlo Park, CA (United States)
2015-01-15
Electrically charged black holes with flat event horizon in anti-de Sitter space have received much attention due to various applications in Anti-de Sitter/Conformal Field Theory (AdS/CFT) correspondence, from modeling the behavior of quark-gluon plasma to superconductor. Critical to the physics on the dual field theory is the fact that when embedded in string theory, black holes in the bulk may become vulnerable to instability caused by brane pair-production. Since dilation arises naturally in the context of string theory, we study the effect of coupling dilation to Maxwell field on the stability of flat charged AdS black holes.
Hendi, S. H.; Talezadeh, M. S.
2017-01-01
Regarding the wide applications of dilaton gravity in the presence of electrodynamics, we introduce a suitable Lagrangian for the coupling of dilaton with gauge field. There are various Lagrangians which show the coupling between scalar fields and electrodynamics with correct special situations. In this paper, taking into account conformal transformation of Brans-Dicke theory with an electrodynamics Lagrangian, we show that how scalar field should couple with electrodynamics in dilaton gravity. In other words, in order to introduce a correct Lagrangian of dilaton gravity, one should check at least two requirements: compatibility with Brans-Dicke theory and appropriate special situations. Finally, we apply the mentioned method to obtain analytical solutions of dilaton-Born-Infeld and Brans-Dicke-Born-Infeld theories with energy dependent spacetime.
Hendi, S H
2016-01-01
Regarding the wide applications of dilaton gravity in the presence of electrodynamics, we introduce a suitable Lagrangian for the coupling of dilaton with gauge field. There are various Lagrangians which show the coupling between scalar fields and electrodynamics with correct special situations. In this paper, taking into account conformal transformation of Brans-Dick theory with an electrodynamics Lagrangian, we show that how the scalar field should couple with electrodynamics in dilaton gravity. In other words, in order to introduce a correct Lagrangian of dilaton gravity, one should check at least two requirements: compatibility with Brans-Dick theory and appropriate special situations. Finally, we apply the mentioned method to obtain analytical solutions of dilaton-Born-Infeld and Brans-Dicke-Born-Infeld theories with energy dependent spacetime.
Black branes on the linear dilaton background
Clément, G; Clement, Gerard; Gal'tsov, Dmitri
2004-01-01
We show that the complete static black p-brane supergravity solution with a single charge contains two and only two branches with respect to behavior at infinity in the transverse space. One branch is the standard family of asymptotically flat black branes, and another is the family of black branes which asymptotically approach the linear dilaton background with antisymmetric form flux (LDB). Such configurations were previously obtained in the near-horizon near-extreme limit of the dilatonic asymptotically flat $p$-branes, and used to describe the thermal phase of field theories involved in the DW/QFT dualities and the thermodynamics of little string theory in the case of the NS5-brane. Here we show by direct integration of the Einstein equations that the asymptotically LDB $p$-branes are indeed exact supergravity solutions, and we prove a new uniqueness theorem for static $p$-brane solutions satisfying cosmic censorship. In the non-dilatonic case, our general non-asymptotically flat p-branes are uncharged bl...
Holography of Dyonic Dilaton Black Branes
Goldstein, Kevin; Kachru, Shamit; Prakash, Shiroman; Trivedi, Sandip P; Westphal, Alexander
2010-01-01
We study black branes carrying both electric and magnetic charges in Einstein-Maxwell theory coupled to a dilaton-axion in asymptotically anti de Sitter space. After reviewing and extending earlier results for the case of electrically charged branes, we characterise the thermodynamics of magnetically charged branes. We then focus on dyonic branes in theories which enjoy an $SL(2,R)$ electric-magnetic duality. Using $SL(2,R)$, we are able to generate solutions with arbitrary charges starting with the electrically charged solution, and also calculate transport coefficients. These solutions all exhibit a Lifshitz-like near-horizon geometry. The system behaves as expected for a charged fluid in a magnetic field, with non-vanishing Hall conductance and vanishing DC longitudinal conductivity at low temperatures. Its response is characterised by a cyclotron resonance at a frequency proportional to the magnetic field, for small magnetic fields. Interestingly, the DC Hall conductance is related to the attractor value ...
Rotating Dilaton Black Strings Coupled to Exponential Nonlinear Electrodynamics
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Ahmad Sheykhi
2014-01-01
Full Text Available We construct a new class of charged rotating black string solutions coupled to dilaton and exponential nonlinear electrodynamic fields with cylindrical or toroidal horizons in the presence of a Liouville-type potential for the dilaton field. Due to the presence of the dilaton field, the asymptotic behaviors of these solutions are neither flat nor (AdS. We analyze the physical properties of the solutions in detail. We compute the conserved and thermodynamic quantities of the solutions and verify the first law of thermodynamics on the black string horizon. When the nonlinear parameter β2 goes to infinity, our results reduce to those of black string solutions in Einstein-Maxwell-dilaton gravity.
Radiating black holes in Einstein-Maxwell-dilaton theory
Aniceto, Pedro; Rocha, Jorge V
2015-01-01
We construct exact, time-dependent, black hole solutions of Einstein-Maxwell-dilaton theory with arbitrary dilaton coupling, a. For a=1 this theory arises as the four-dimensional low-energy effective description of heterotic string theory. These solutions represent electrically charged, spherically symmetric black holes emitting or absorbing charged null dust and generalize the Vaidya and Bonnor-Vaidya solutions of general relativity and of Einstein-Maxwell theory, respectively. The a=1 case stands out as special, in the sense that it is the only choice of the coupling that allows for a time-dependent dilaton field in this class of solutions. As a by-product, we prove that an electrically charged black hole in this theory cannot be overcharged by bombarding it with a stream of electrically charged null dust. This provides an example of cosmic censorship observance in a string theory setting.
Stationary Scalar Clouds Around Maximally Rotating Linear Dilaton Black Holes
Sakalli, I
2016-01-01
We investigate the wave dynamics of a charged massive scalar field propagating in a maximally rotating (extremal) linear dilaton black hole geometry. We prove the existence of a discrete and infinite family of resonances describing non-decaying (stationary) scalar configurations (clouds) enclosing these rapidly rotating black holes. The results obtained signal the potential stationary scalar field distributions (dark matter) around the extremal linear dilaton black holes. In particular, we analytically compute the effective height of those clouds above the center of the black hole.
Li, Huai-Fan; Zhang, Li-Chun; Zhao, Ren
2016-01-01
Using Maxwell's equal area law, we discuss the phase transition of higher dimensional charged topological dilaton AdS black holes with a nonlinear source. The coexisting region of the two phases is found and we depict the coexistence region in $P-v$ diagrams. The two-phase equilibrium curves in $P-T$ diagrams are plotted, and we take the first order approximation of volume $v$ in the calculation. To better compare with a general thermodynamic system, the Clapeyron equation is derived for higher dimensional charged topological black hole with a nonlinear source. The latent heat of isothermal phase transition is investigated. We also study the effect of the parameters of the black hole on the region of two-phases coexistence. The results show that the black hole may go through a small-large phase transition similar to those of usual non-gravity thermodynamic systems.
Quantization of rotating linear dilaton black holes
Sakalli, I
2014-01-01
In this paper, we firstly prove that the adiabatic invariant quantity, which is commonly used in the literature for quantizing the rotating black holes (BHs) is fallacious. We then show how its corrected form should be. The main purpose of this paper is to study the quantization of 4-dimensional rotating linear dilaton black hole (RLDBH) spacetime describing with an action, which emerges in the Einstein-Maxwell-Dilaton-Axion (EMDA) theory. The RLDBH spacetime has a non-asymptotically flat (NAF) geometry. They reduces to the linear dilaton black hole (LDBH) metric when vanishing its rotation parameter "a". While studying its scalar perturbations, it is shown that the Schr\\"odinger-like wave equation around the event horizon reduces to a confluent hypergeometric differential equation. Then the associated complex frequencies of the quasinormal modes (QNMs) are computed. By using those QNMs in the true definition of the rotational adiabatic invariant quantity, we obtain the quantum spectra of entropy/area for the...
Institute of Scientific and Technical Information of China (English)
杨波
2008-01-01
在Dilaton-Maxwell黑洞中,将4个耦合的Dirac方程简化,作乌龟坐标变换,得到视界面附近处的辐射温度函数.采用薄膜brick-wall模型计算出该黑洞的熵,选择合适的截断因子,得到熵与该黑洞视界面积成正比的结论.
Quantization of rotating linear dilaton black holes
Energy Technology Data Exchange (ETDEWEB)
Sakalli, I. [Eastern Mediterranean University, Department of Physics, Mersin 10 (Turkey)
2015-04-15
In this paper, we focus on the quantization of four-dimensional rotating linear dilaton black hole (RLDBH) spacetime describing an action, which emerges in the Einstein-Maxwell-dilaton-axion (EMDA) theory. RLDBH spacetime has a non-asymptotically flat geometry. When the rotation parameter ''a'' vanishes, the spacetime reduces to its static form, the so-called linear dilaton black hole (LDBH) metric. Under scalar perturbations, we show that the radial equation reduces to a hypergeometric differential equation. Using the boundary conditions of the quasinormal modes (QNMs), we compute the associated complex frequencies of the QNMs. In a particular case, QNMs are applied in the rotational adiabatic invariant quantity, and we obtain the quantum entropy/area spectra of the RLDBH. Both spectra are found to be discrete and equidistant, and independent of the a-parameter despite the modulation of QNMs by this parameter. (orig.)
Dilaton black holes coupled to nonlinear electrodynamic field
Sheykhi, A
2015-01-01
The theory of nonlinear electrodynamics has got a lot of attentions in recent years. It was shown that Born-Infeld nonlinear electrodynamics is not the only modification of the linear Maxwell's field which keeps the electric field of a charged point particle finite at the origin, and other type of nonlinear Lagrangian such as exponential and logarithmic nonlinear electrodynamics can play the same role. In this paper, we generalize the study on the exponential nonlinear electrodynamics by adding a scalar dilaton field to the action. By suitably choosing the coupling of the matter field to the dilaton field, we vary the action and obtain the corresponding field equations. Then, by making a proper ansatz, we construct a new class of charged dilaton black hole solutions coupled to the exponential nonlinear electrodynamics field in the presence of two Liouville-type potentials for the dilaton field. Due to the presence of the dilaton field, the asymptotic behavior of these solutions are neither flat nor (A)dS. In ...
Critical behavior of Born-Infeld dilaton black holes
Dehghani, M H; Dayyani, Z
2016-01-01
We explore the critical behavior of (n+1)-dimensional topological Born-Infeld-dilaton black holes in an extended phase space. We treat the cosmological constant and the Born-Infeld (BI) parameter as the thermodynamic pressure and BI vacuum polarization which can vary. We obtain thermodynamic quantities of the system such as pressure, temperature, Gibbs free energy, and investigate the behaviour of these quantities. We also study the analogy of the van der Waals liquid-gas system with the Born-Infeld-dilaton black holes in canonical ensemble in which we can treat the black hole charge as a fixed external parameter. Moreover, we show that the critical values of pressure, temperature and volume are physical provided the coupling constant of dilaton gravity is less than one and the horizon is sphere. Finally, we calculate the critical xponents and show that although thermodynamic quantities depend on the dilaton oupling constant, BI parameter and the dimension of the spacetime, they are universal and are independ...
Fermions tunneling from the Horowitz-Strominger Dilaton black hole
Institute of Scientific and Technical Information of China (English)
无
2009-01-01
Based on the work of Kerner and Mann, fermions tunneling from the Horowitz-Strominger Dilaton black hole on the membrane is studied. Owing to the coupling among electromagnetic field, matter field and gravity field, the Dirac equation of charged particles is introduced, and according to that, the expected emission temperature is obtained. After the self-gravitational interaction is considered, it is found that the tunneling rate of fermions also satisfies the underlying Unitary theory as the case of scalar particles.
Holographic conductivity for logarithmic charged dilaton-Lifshitz solutions
Directory of Open Access Journals (Sweden)
A. Dehyadegari
2016-07-01
Full Text Available We disclose the effects of the logarithmic nonlinear electrodynamics on the holographic conductivity of Lifshitz dilaton black holes/branes. We analyze thermodynamics of these solutions as a necessary requirement for applying gauge/gravity duality, by calculating conserved and thermodynamic quantities such as the temperature, entropy, electric potential and mass of the black holes/branes. We calculate the holographic conductivity for a (2+1-dimensional brane boundary and study its behavior in terms of the frequency per temperature. Interestingly enough, we find out that, in contrast to the Lifshitz–Maxwell-dilaton black branes which have conductivity for all z, here in the presence of nonlinear gauge field, the holographic conductivity does exist provided z≤3 and vanishes for z>3. It is shown that independent of the nonlinear parameter β, the real part of the conductivity is the same for a specific value of frequency per temperature in both AdS and Lifshitz cases. Besides, the behavior of real part of conductivity for large frequencies has a positive slope with respect to large frequencies for a system with Lifshitz symmetry whereas it tends to a constant for a system with AdS symmetry. This behavior may be interpreted as existence of an additional charge carrier rather than the AdS case, and is due to the presence of the scalar dilaton field in model. Similar behavior for optical conductivity of single-layer graphene induced by mild oxygen plasma exposure has been reported.
Holographic conductivity for logarithmic charged dilaton-Lifshitz solutions
Dehyadegari, A.; Sheykhi, A.; Kord Zangeneh, M.
2016-07-01
We disclose the effects of the logarithmic nonlinear electrodynamics on the holographic conductivity of Lifshitz dilaton black holes/branes. We analyze thermodynamics of these solutions as a necessary requirement for applying gauge/gravity duality, by calculating conserved and thermodynamic quantities such as the temperature, entropy, electric potential and mass of the black holes/branes. We calculate the holographic conductivity for a (2 + 1)-dimensional brane boundary and study its behavior in terms of the frequency per temperature. Interestingly enough, we find out that, in contrast to the Lifshitz-Maxwell-dilaton black branes which have conductivity for all z, here in the presence of nonlinear gauge field, the holographic conductivity does exist provided z ≤ 3 and vanishes for z > 3. It is shown that independent of the nonlinear parameter β, the real part of the conductivity is the same for a specific value of frequency per temperature in both AdS and Lifshitz cases. Besides, the behavior of real part of conductivity for large frequencies has a positive slope with respect to large frequencies for a system with Lifshitz symmetry whereas it tends to a constant for a system with AdS symmetry. This behavior may be interpreted as existence of an additional charge carrier rather than the AdS case, and is due to the presence of the scalar dilaton field in model. Similar behavior for optical conductivity of single-layer graphene induced by mild oxygen plasma exposure has been reported.
Sakalli, I.
2016-10-01
Charged massive scalar field perturbations are studied in the gravitational, electromagnetic, dilaton, and axion fields of rotating linear dilaton black holes. In this geometry, we separate the covariant Klein-Gordon equation into radial and angular parts and obtain the exact solutions of both the equations in terms of the confluent Heun functions. Using the radial solution, we study the problems of resonant frequencies, entropy/area quantization, and greybody factor. We also analyze the behavior of the wave solutions near the event horizon of the rotating linear dilaton black hole and derive its Hawking temperature via the Damour-Ruffini-Sannan method.
Black Holes and Two-Dimensional Dilaton Gravity
Futamase, T.; Hotta, M.; Itoh, Y.
1998-01-01
We study the conditions for 2-dimensional dilaton gravity models to have dynamical formation of black holes and construct all such models. Furthermore we present a parametric representation of the general solutions of the black holes.
Fermions tunneling from the Horowitz-Strominger Dilaton black hole
Institute of Scientific and Technical Information of China (English)
LI Oiang; ZENG XiaoXiong
2009-01-01
Based on the work of Kerner and Mann, fermions tunneling from the Horowitz-Strominger Dilaton black hole on the membrane is studied. Owing to the coupling among electromagnetic field, matter field and gravity field, the Dirac equation of charged particles is introduced, and according to that, the expected emission temperature is obtained. After the self-gravitational interaction is considered, it is found that the tunneling rate of fermions also satisfies the underlying Unitary theory as the case of scalar parti-cles.
Quantum Information Measurements for Garfinkle-Horne Dilaton Black Holes
Institute of Scientific and Technical Information of China (English)
GE Xian-Hui; SHEN You-Gen
2004-01-01
@@ The quantum non-cloning theorem is discussed for Garfinkle-Horne dilaton black holes. It is found that if the black hole complementarity principle is correct, then it will be questioned whether the quantum non-cloning theorem is well established inside the inner horizon. It is also found that another complementarity principle may be needed inside the inner horizon of the Garfinkle-Horne dilaton black hole.
Rotating black holes in dilatonic Einstein-Gauss-Bonnet theory.
Kleihaus, Burkhard; Kunz, Jutta; Radu, Eugen
2011-04-15
We construct generalizations of the Kerr black holes by including higher-curvature corrections in the form of the Gauss-Bonnet density coupled to the dilaton. We show that the domain of existence of these Einstein-Gauss-Bonnet-dilaton (EGBD) black holes is bounded by the Kerr black holes, the critical EGBD black holes, and the singular extremal EGBD solutions. The angular momentum of the EGBD black holes can exceed the Kerr bound. The EGBD black holes satisfy a generalized Smarr relation. We also compare their innermost stable circular orbits with those of the Kerr black holes and show the existence of differences which might be observable in astrophysical systems.
Reissner-Nordström Type Black Holes in Dilaton-Axion Gravity
Galtsov, D V
1996-01-01
A $2p + 5$ parametric family of black holes is constructed in dilaton--axion gravity with $p$ vector fields using a holomorphic representation of U--duality in three dimensions. The set of free parameters includes a mass, $2p$ electric/magnetic charges, a NUT charge, one of the scalar charges, and asymptotic values of dilaton and axion. The metric of the non--extremal black holes has a Reissner--Nordström type structure and generically possesses an internal horizon. However in the extremal limit the generic solution exibits a dilatonic type null singularity. Only in the case of the orthogonal electric and magnetic charges (if $p>1$) the extremal solution may have a non--singular event horizon.
Soroushfar, Saheb; Saffari, Reza; Sahami, Ehsan
2016-07-01
In this paper, we consider the timelike and null geodesics around the static (GMGHS, magnetically charged GMGHS, electrically charged GMGHS) and the rotating (Kerr-Sen dilaton-axion) dilaton black holes. The geodesic equations are solved in terms of Weierstrass elliptic functions. To classify the trajectories around the black holes, we use the analytical solution and effective potential techniques and then characterize the different types of the resulting orbits in terms of the conserved energy and angular momentum. Also, using the obtained results we study astrophysical applications.
Multidimensional extremal dilatonic black holes in string-like model with cosmological term
Ivashchuk, V D
1996-01-01
A string-like model with the "cosmological constant" \\Lambda is considered. The Maki-Shiraishi multi-black-hole solution \\cite{MS1} is generalized to space-times with a Ricci-flat internal space. For \\Lambda = 0 the obtained solution in the one-black-hole case is shown to coincide with the extreme limit of the charged dilatonic black hole solution \\cite{BI,BM}. The Hawking temperature T_H for the solution \\cite{BI,BM} is presented and its extreme limit is considered. For the string value of dilatonic coupling the temperature T_H does not depend upon the internal space dimension.
Tunneling Radiation of Massive Vector Bosons from Dilaton Black Holes
Li, Ran; Zhao, Jun-Kun; Wu, Xing-Hua
2016-07-01
It is well known that Hawking radiation can be treated as a quantum tunneling process of particles from the event horizon of black hole. In this paper, we attempt to apply the massive vector bosons tunneling method to study the Hawking radiation from the non-rotating and rotating dilaton black holes. Starting with the Proca field equation that govern the dynamics of massive vector bosons, we derive the tunneling probabilities and radiation spectrums of the emitted vector bosons from the static spherical symmetric dilatonic black hole, the rotating Kaluza—Klein black hole, and the rotating Kerr—Sen black hole. Comparing the results with the blackbody spectrum, we satisfactorily reproduce the Hawking temperatures of these dilaton black holes, which are consistent with the previous results in the literature. Supported by National Natural Science Foundation of China under Grant No. 11205048
Phase transition and thermodynamic geometry of Einstein-Maxwell-dilaton black holes
Hendi, S H; Panahiyan, S; Panah, B Eslam
2015-01-01
In this paper, we consider a linearly charged dilatonic black holes and study their thermodynamical behavior in the context of phase transition and thermodynamic geometry. We show that, depending on the values of the parameters, these type of black holes may enjoy two types of phase transition. We also find that there are three critical behaviors near the critical points for these black holes; nonphysical unstable to physical stable, large to small, and small to large black holes phase transition. Next, we employ a thermodynamical metric for studying thermodynamical geometry of these black holes. We show that the characteristic behavioral of Ricci scalar of this metric enables one to recognize the type of phase transition and critical behavior of the black holes near phase transition points. Finally, we will extend thermodynamical space by considering dilaton parameter as extensive parameter. We will show that by this consideration, Weinhold, Ruppeiner and Quevedo metrics provide extra divergencies which are ...
Hawking Radiation of Linear Dilaton Black Holes in Various Theories
Pasaoglu, H
2009-01-01
Using the Damour-Ruffini-Sannan, the Parikh-Wilczek and the thin film brick-wall models, we investigate the Hawking radiation of uncharged massive particles from 4-dimensional linear dilaton black holes, which are the solutions to Einstein-Maxwell-Dilaton, Einstein-Yang-Mills-Dilaton and Einstein-Yang-Mills-Born-Infeld-Dilaton theories. Our results show that the tunneling rate is related to the change of Bekenstein-Hawking entropy. Contrary to the many studies in the literature, here the emission spectrum is precisely thermal. This implies that the derived emission spectrum is not consistent with the unitarity of the quantum theory, which would possibly lead to the information loss.
Hydrodynamics and Elasticity of Charged Black Branes
DEFF Research Database (Denmark)
Gath, Jakob
charge and a dilaton coupling. For the case of Maxwell black branes we furthermore compute the charge diffusion constant. We find that the shear viscosity to entropy bound is saturated and comment on proposed bounds for the bulk viscosity to entropy ratio. With the transport coecients we compute......)isotropic uid branes in terms of two sets of response coecients, the Young modulus and the piezoelectric moduli. We subsequently consider a large class of examples in gravity of this effective theory. In particular, we consider dilatonic black p-branes in two different settings: charged under a Maxwell gauge...... as a seed solution, we obtain a class of charged black brane geometries carrying smeared Maxwell charge in Einstein-Maxwell-dilaton theory. In the specific case of ten-dimensional space-time we furthermore use T-duality to generate bent black branes with higher-form charge, including smeared D...
Letter: Dilatonic Black Hole Entropy Without Brick Walls
Ren, Zhao; Sheng-Li, Zhang
2004-09-01
The properties of the thermal radiation are discussed by using the new equation of state density motivated by the generalized uncertainty relation in the quantum gravity. There is no burst at the last stage of the emission of dilatonic black hole. When the new equation of state density is utilized to investigate the entropy of a bosonic field and fermionic field outside the horizon of a static dilatonic black hole, the divergence appearing in the brick wall model is removed, without any cutoff. It is derived from the contribution of the vicinity of the horizon that the entropy is proportional to the horizon area.
Black holes in three-dimensional dilaton gravity theories
Sá, P M; Lemos, J P S; Sa, Paulo M; Kleber, Antares; Lemos, Jose P S
1995-01-01
Three dimensional black holes in a generalized dilaton gravity action theory are analysed. The theory is specified by two fields, the dilaton and the graviton, and two parameters, the cosmological constant and the Brans-Dicke parameter. It contains seven different cases, of which one distinguishes as special cases, string theory, general relativity and a theory equivalent to four dimensional general relativity with one Killing vector. We study the causal structure and geodesic motion of null and timelike particles in the black hole geometries and find the ADM masses of the different solutions.
Solitons and black holes in Einstein-Born-Infeld-dilaton theory
Clément, G; Clement, Gerard; Gal'tsov, Dmitri
2000-01-01
Static spherically symmetric asymptotically flat solutions to the U(1) Born-Infeld theory coupled to gravity and to a dilaton are investigated. The dilaton enters in such a way that the theory is $SL(2,R)$- symmetric for a unit value of the dilaton coupling constant. We find globally regular solutions for any value of the effective coupling which is the ratio of the gravitational and dilaton couplings; they form a continuous sequence labeled by the sole free parameter of the local solution near the origin. The allowed values of this parameter are bounded from below, and, as the limiting value is approached, the mass and the dilaton charge rise indefinitely and tend to a strict equality (in suitable units). Together with the electric charge they saturate the BPS bound of the corresponding linear U(1) theory. Beyond this boundary the solutions become compact (singular), while the limiting solution at the exact boundary value is non-compact and non-asymptotically flat. The black holes in this theory exist for an...
An Electrically charged doubly spinning dipole black ring
Rocha, J.V.; Rodriguez, M.J.; Varela Rizo, O. M.
2012-01-01
We present a new asymptotically flat, doubly spinning black ring of D = 5 Einstein-Maxwell-dilaton theory with Kaluza-Klein dilaton coupling. Besides the mass and two angular momenta, the solution displays both electric charge and (magnetic) dipole charge. The class of solutions that are free from c
Radiating black holes in Einstein-Maxwell-dilaton theory and cosmic censorship violation
Aniceto, Pedro; Pani, Paolo; Rocha, Jorge V.
2016-05-01
We construct exact, time-dependent, black hole solutions of Einstein-Maxwell-dilaton theory with arbitrary dilaton coupling, a. For a = 1 this theory arises as the four-dimensional low-energy effective description of heterotic string theory. These solutions represent electrically charged, spherically symmetric black holes emitting or absorbing charged null fluids and generalize the Vaidya and Bonnor-Vaidya solutions of general relativity and of Einstein-Maxwell theory, respectively. The a = 1 case stands out as special, in the sense that it is the only choice of the coupling that allows for a time-dependent dilaton field in this class of solutions. As a by-product, when a = 1 we show that an electrically charged black hole in this theory can be overcharged by bombarding it with a stream of electrically charged null fluid, resulting in the formation of a naked singularity. This provides an example of cosmic censorship violation in an exact dynamical solution to low-energy effective string theory and in a case in which the total stress-energy tensor satisfies all energy conditions. When a ≠ 1, our solutions necessarily have a time-independent scalar field and consequently cannot be overcharged.
Ruppeiner Geometry of (2 + 1)-Dimensional Spinning Dilaton Black Hole*
Institute of Scientific and Technical Information of China (English)
CHEN Xiu-Wu; WEI Shao-Wen; LIU Yu-Xiao
2011-01-01
In this paper, we study the geometrothermodynamics of (2 + 1)-dimensional spinning dilaton black hole.We show that the Ruppeiner curvature vanishes, which implies that there exist no phase transitions and thermodynamic interactions. However when the thermodynamics fluctuation is included, the geometry structure is reconsidered. The non-vanishing Ruppeiner curvature is obtained, which means the phase space is non-flat. We also study the phase transitions and show that it can indeed take place at some points.
Rotating black holes in Einstein-Dilaton-Gauss-Bonnet gravity with finite coupling
Maselli, Andrea; Gualtieri, Leonardo; Ferrari, Valeria
2015-01-01
Among various strong-curvature extensions to General Relativity, Einstein-Dilaton-Gauss-Bonnet gravity stands out as the only nontrivial theory containing quadratic curvature corrections while being free from the Ostrogradsky instability to any order in the coupling parameter. We derive an approximate stationary and axisymmetric black-hole solution of this gravitational theory in closed form, which is quadratic in the black-hole spin angular momentum and of seventh order in the coupling parameter of the theory. This extends previous work that obtained the corrections to the metric only at the leading order in the coupling parameter, and allows us to consider values of the coupling parameter close to the maximum permitted by theoretical constraints. We compute some geometrical properties of this solution, such as the dilaton charge, the moment of inertia and the quadrupole moment, and its geodesic structure, including the innermost-stable circular orbit and the epicyclic frequencies for massive particles. The ...
Shadow cast by a Kaluza-Klein spinning dilaton black hole
Amarilla, Leonardo
2015-01-01
We examine the shadow of a rotating Kaluza-Klein black hole in Einstein gravity coupled to a Maxwell field and a dilaton. The size and the shape of the shadow depend on the mass, the charge, and the angular momentum of the compact object. For a given mass, the size increases with the rotation parameter and decreases with the electric charge. The distortion with respect to the non rotating case grows with the charge and the rotation parameter. For fixed values of these parameters, the shadow is slightly larger and less deformed than in the Kerr-Newman case.
The information entropy of a static dilaton black hole
Institute of Scientific and Technical Information of China (English)
2008-01-01
In accordance with holographic principle, by calculating the statistical entropy of the quantum field just at the event horizon of the Garfinkle-Horowitz-Strominger dilaton black hole, the information entropy of the black hole was investigated and the Bekenstein-Hawking formula was obtained. The results show that black hole entropy is identical with the statistical entropy of the quantum field at the horizon. Using the generalized uncertainty relation, the divergence of the state density near the event horizon in usual quantum field theory was removed, and the cutoffs and the little mass approximation in the heat gas method of black hole entropy were avoided. Thus, the microstates of the massive scalar field just at the event horizon of the static dilaton black hole were studied directly and a description on holograph principle was presented. By using residue theorem, the integral difficulty in the calculation was overcome, and the information entropy and the Bekenstein-Hawking formula were obtained quantitatively. Compared with the black hole entropy from the loop quantum gravity, the consistency of methods and results of calculating black hole entropy in non-commutative quantum field theory and loop quantum gravity was investigated. By this, the gravity correction constant in the generalized uncertainty relation was suggested and the sense of holographic principle was discussed.
Dilatonic BTZ black holes with power-law field
Hendi, S. H.; Eslam Panah, B.; Panahiyan, S.; Sheykhi, A.
2017-04-01
Motivated by low energy effective action of string theory and numerous applications of BTZ black holes, we will consider minimal coupling between dilaton and nonlinear electromagnetic fields in three dimensions. The main goal is studying thermodynamical structure of black holes in this set up. Temperature and heat capacity of these black holes are investigated and a picture regarding their phase transitions is given. In addition, the role and importance of studying the mass of black holes is highlighted. We will see how different parameters modify thermodynamical quantities, hence thermodynamical structure of these black holes. In addition, geometrical thermodynamics is used to investigate thermodynamical properties of these black holes. In this regard, the successful method is presented and the nature of interaction around bound and phase transition points is studied.
Shadow of a Kerr-Sen dilaton-axion Black Hole
Dastan, Sara; Soroushfar, Saheb
2016-01-01
We analyze the shadow of charged stationary axially symmetric space-time (Kerr-Sen dilaton-axion black hole). This black hole is defined by a mass $M$, a spin $a$ and $r_{\\alpha}=Q^{2}/M$, where $Q$ is the electric charge. Shadows are investigated in two conditions, i) for an observer at infinity in vacuum and ii) for an observer at infinity in the presence of plasma with radial power-low density. In vacuum, the shadow of this black hole depends on charge and spin parameter. We can see that, increasing electric charge, $Q$ decreases the size of shadow. Also, increasing spin parameter $a$ decreases the size of shadow. However, in existence of plasma, parameter of plasma like refraction index, $n$, playing an important role on shadows. In fact, decreasing refraction index decreases the size of shadow.
Phantom collapse of electrically charged scalar field in dilaton gravity
Nakonieczna, Anna
2013-01-01
Our research focus on gravitational collapse of electrically charged scalar field in dilaton gravity and in the presence of phantom coupling. We examine dynamical behaviour of the scalar field coupled to Maxwell field when gravitational interactions have form consistent with the low-energy limit of the string theory. Moreover, we allow the evolving fields to have negative sign in front of the respective kinetic term of the Lagrangian. The main aim of our studies is to investigate in what manner does the phantom nature of either Maxwell or dilaton fields (or both of them) affect the outcomes of the collapse. It turns out that the influence is crucial to the obtained spacetime structures. Negative kinetic energy of one (or both) of the fields delays, changes the course or even prevents the collapse.
Dayyani, Z; Dehghani, M H
2016-01-01
We investigate the critical behavior of an $(n+1)$-dimensional topological dilaton black holes, in an extended phase space in both canonical and grand-canonical ensembles, when the gauge field is in the form of power-Maxwell field. In order to do this we introduce for the first time the counterterms that remove the divergences of the action in dilaton gravity for the solutions with curved boundary. Using the counterterm method, we calculate the conserved quantities and the action and therefore Gibbs free energy in both the canonical and grand-canonical ensembles. We treat the cosmological constant as a thermodynamic pressure, and its conjugate quantity as a thermodynamic volume. In the presence of power-Maxwell field, we find an analogy between the topological dilaton black holes with van der Walls liquid-gas system in all dimensions provided the dilaton coupling constant $\\alpha$ and the power parameter $p$ are chosen properly. Interestingly enough, we observe that the power-Maxwell dilaton black holes admit...
Holographic Conductivity for Logarithmic Charged Dilaton-Lifshitz Solutions
Dehyadegari, A; Zangeneh, M Kord
2016-01-01
We disclose the effects of the logarithmic nonlinear electrodynamics on the holographic conductivity of Lifshitz dilaton black holes/branes. We analyze thermodynamics of these solutions as a necessary requirement for applying gauge/gravity duality, by calculating conserved and thermodynamic quantities such as the temperature, entropy, electric potential and mass of the black holes/branes. We calculate the holographic conductivity for a $(2+1)$-dimensional brane boundary and study its behavior in terms of the frequency per temperature. Interestingly enough, we find out that, in contrast to the Lifshitz-Maxwell-dilaton black branes which has conductivity for all $z$, here in the presence of nonlinear gauge field, the holographic conductivity do exist provided $z\\leq3$ and vanishes for $z>3$. It is shown that independent of the nonlinear parameter $\\beta$, the real part of the conductivity is the same for a specific value of frequency per temperature in both AdS and Lifshitz cases. Besides, the behavior of real ...
Dilaton minimally coupled to 2 + 1 Einstein Maxwell fields; stationary cyclic symmetric black holes
Garcia-Diaz, A A
2014-01-01
Using the Schwarzschild coordinate frame for a static cyclic symmetric metric in 2 + 1 Einstein gravity coupled to a electric Maxwell field and a dilaton logarithmically depending on the radial coordinate in the presence of an exponential potential the general solution of the Einstein Maxwell dilaton equations is derived and it is identified with the Chan Mann charged dilaton solution. Via a general SL(2;R) transformation, applied on the obtained charged dilaton metric, a family of stationary dilaton solutions has been generated; these solutions possess five parameters: dilaton and cosmological constants , charge, momentum, and mass for some values of them. All the exhibited solutions have been characterized by their quasi-local energy, mass, and momentum through their series expansions at spatial infinity. The structural functions determining these solutions increase as the radial coordinate does, hence they do not exhibit an dS AdS behavior at infinity Moreover, the algebraic structure of the Maxwell field,...
Symmetries and black holes in 2D dilaton gravity
Cruz, J; Navarro, M; Talavera, C F
1996-01-01
We study global symmetries of generic 2D dilaton gravity models. Using a non-linear sigma model formulation we show that the unique theories admitting special conformal symmetries are the models with an exponential potential V \\propto e^{\\beta\\phi} ( S ={1\\over2\\pi} \\int d^2 x \\sqrt{-g} [ R \\phi + 4 \\lambda^2 e^{\\beta\\phi} ]), which include the model of Callan, Giddings, Harvey and Strominger (CGHS) as a particular though limiting (\\beta=0) case. These models give rise to black hole solutions with a mass-dependent temperature. The underlying conformal symmetry can be maintained in a natural way in the one-loop effective action, thus implying the exact solvability of the semiclassical theory including back-reaction. Moreover, we also introduce three different classes of non-conformal transformations which are symmetries for generic 2D dilaton gravity models. Special linear combinations of these transformations turn out to be the conformal symmetries of the CGHS and V \\propto e^{\\beta\\phi} models. We show that,...
Quantum Spectrum of Stationary Axisymmetric Einstein-Maxwell Dilaton-Axion Black Hole
Institute of Scientific and Technical Information of China (English)
WANG Jin; JING Ji-Liang
2005-01-01
@@ The horizon area spectrum of a stationary axisymmetric Einstein-Maxwell Dilaton-Axion (EMDA) black hole is studied by using Gour-Medved's method. It is found that the quantized area operator can be expressed interms of two quantum numbers,i.e.A=8πh(1/2+n+l),where n and l are strictly non-negative integers and related respectively to the mass and angular momentum. The result shows that there is qualitatively a propertydifference between the quantum spectrum of the EMDA black hole which obtained from string theory and theone of the Kerr-Newman black hole which obtained from generalrelativity, although both they are characterizedby mass, angular momentum and charge.
Electric Charge in Interaction with Magnetically Charged Black Holes
Kim, J H
2007-01-01
We examine the angular momentum of an electric charge e placed at rest outside a dilaton black hole with magnetic charge Q. The electromagnetic angular momentum which is stored in the electromagnetic field outside the black hole shows several common features regardless of the dilaton coupling strength, though the dilaton black holes are drastically different in their spacetime structure depending on it. First, the electromagnetic angular momentum depends on the separation distance between the two objects and changes monotonically from eQ to 0 as the charge goes down from infinity to the horizon, if rotational effects of the black hole are discarded. Next, as the black hole approaches extremality, however, the electromagnetic angular momentum tends to be independent of the distance between the two objects. It is then precisely $eQ$ as in the electric charge and monopole system in flat spacetime. We discuss why these effects are exhibited and argue that the above features are to hold in widely generic settings ...
The Question of Abelian Higgs Hair Expulsion from Extremal Dilaton Black Holes
Moderski, R; Moderski, Rafal; Rogatko, Marek
1999-01-01
It has been argued that the extremal dilaton black holes exhibit a flux expulsion of Abelian-Higgs vortices. We re-examine carefully the problem and give analytic proofs for the flux expulsion always takes place. We also conduct numerical analysis of the problem using three initial data sets on the horizon of an extreme dilatonic black hole, namely, core, vacuum and sinusoidal initial conditions. We also show that an Abelian-Higgs vortex can end on the extremal dilaton black hole. Concluding, we calculate the backreaction of the Abelian-Higgs vortex on the geometry of the extremal black hole and drew a conclusion that a straight cosmic string and the extreme dilaton black hole hardly knew their presence.
Ehlers-Harrison transformations and black holes in Dilaton-Axion Gravity with multiple vector fields
Galtsov, D V
1997-01-01
Dilaton-axion gravity with $p U(1)$ vector fields is studied on space-times admitting a timelike Killing vector field. Three-dimensional sigma-model is derived in terms of Kähler geometry, and holomorphic representation of the SO(2,2+p) global symmetry is constructed. A general static black hole solution depending on $2p+5$ parameters is obtained via SO(2,2+p) covariantization of the Schwarzschild solution. The metric in the curvature coordinates looks as the variable mass Reissner-Nordström one and generically possesses two horizons. The inner horizon is pushed to the singularity if electric and magnetic SO(p) charge vectors are parallel. For non-parallel charges the inner horizon has a finite area except for an extremal limit when this property is preserved only for orthogonal charges. Extremal dyon configurations with orthogonal charges have finite horizon radii continuously varying from zero to the ADM mass. New general solution is endowed with a NUT parameter, asymptotic values of dilaton and axion, an...
Hamiltonian thermodynamics of three-dimensional dilatonic black hole
Dias, Gonçalo A S
2008-01-01
The action for a class of three-dimensional dilaton-gravity theories with a cosmological constant can be recast in a Brans-Dicke type action, with its free $\\omega$ parameter. These theories have static spherically symmetric black holes. Those with well formulated asymptotics are studied through a Hamiltonian formalism, and their thermodynamical properties are found out. The theories studied are general relativity ($\\omega\\to\\infty$), a dimensionally reduced cylindrical four-dimensional general relativity theory ($\\omega=0$), and a theory representing a class of theories ($\\omega=-3$). The Hamiltonian formalism is setup in three dimensions through foliations on the right region of the Carter-Penrose diagram, with the bifurcation 1-sphere as the left boundary, and anti-de Sitter infinity as the right boundary. The metric functions on the foliated hypersurfaces are the canonical coordinates. The Hamiltonian action is written, the Hamiltonian being a sum of constraints. One finds a new action which yields an unc...
Electroelasticity of Charged Black Branes
Armas, Jay; Obers, Niels A
2013-01-01
We present the first order corrected dynamics of fluid branes carrying higher-form charge by obtaining the general form of their equations of motion to pole-dipole order. Assuming linear response theory, we characterize the corresponding effective theory of stationary bent charged (an)isotropic fluid branes in terms of two sets of response coefficients, the Young modulus and the piezoelectric moduli. We subsequently find large classes of examples in gravity of this effective theory, by constructing stationary strained charged black brane solutions to first order in a derivative expansion. Using solution generating techniques and bent neutral black branes as a seed solution, we obtain a class of charged black brane geometries carrying smeared Maxwell charge in Einstein-Maxwell-dilaton gravity. In the specific case of ten-dimensional space-time we furthermore use T-duality to generate bent black branes with higher-form charge, including smeared D-branes of type II string theory. By subsequently measuring the be...
Sheykhi, A.; Naeimipour, F.; Zebarjad, S. M.
2015-06-01
Considering the Lagrangian of the logarithmic nonlinear electrodynamics in the presence of a scalar dilaton field, we obtain a new class of topological black hole solutions of Einstein-dilaton gravity with two Liouville-type dilaton potentials. Black hole horizons and cosmological horizons, in these spacetimes, can be a two-dimensional positive, zero, or negative constant curvature surface. We find that the behavior of the electric field crucially depends on the dilaton coupling constant α . For small α , the electric field diverges near the origin, although its divergency is weaker than the linear Maxwell field. However, with increasing α , the behavior of the electric field, near the origin, approaches to that of the Maxwell field. We also study casual structure, asymptotic behavior, and physical properties of the solutions. We find that, depending on the model parameters, the topological dilaton black holes may have one or two horizons, and even in some cases we encounter a naked singularity without horizon. We compute the conserved and thermodynamic quantities of the spacetime and investigate that these quantities satisfy the first law of thermodynamics. We also probe thermal stability in the canonical and grand canonical ensembles and disclose the effects of the dilaton field as well as nonlinear parameter on the thermal stability of the solutions. Finally, we investigate thermodynamical geometry of the obtained solutions by introducing a new metric and studying the phase transition points due to the divergency of the Ricci scalar. We find that the dilaton field affects the phase transition points of the system.
动态Dilaton-Maxwell黑洞的熵%Entropy of Dilaton- Maxwell black hole
Institute of Scientific and Technical Information of China (English)
宋太平; 侯晨霞
2005-01-01
从动态Dilaton-Maxwell黑洞的时空线元和零曲面方程出发,得到了该黑洞的视界;利用Klein-Gordon方程求得波数,进而采用Wenzel-Kramers-Brillouin近似方法和薄膜Brick-Wall模型,求出了动态Dilaton-Maxwell黑洞的熵,所得的熵正好与该黑洞的视界面积成正比.
Sheykhi, A.; Hajkhalili, S.
2015-11-01
We study topological dilaton black holes of Einstein gravity in the presence of exponential nonlinear electrodynamics. The event horizons of these black holes can be a two-dimensional positive, zero or negative constant curvature surface. We analyze thermodynamics of these solutions by calculating all conserved and thermodynamic quantities and showing that the first law holds on the black hole horizon. Then, we perform the stability analysis in both canonical and grand canonical ensemble and disclose the effects of the dilaton and nonlinear electrodynamics on the thermal stability of the solutions. Finally, we study the phase transition points of these black holes in the thermodynamic geometry approach.
Quantum tunnelling radiation of Einstein-Maxwell-Dilaton-Axion black hole
Institute of Scientific and Technical Information of China (English)
Yang Shu-Zheng; Jiang Qing-Quan; Li Hui-Ling
2005-01-01
By taking the energy conservation and angular momentum conservation into account, the characteristics of the quantum-tunnelling radiation of Einstein-Maxwell-Dilaton-Axion black hole are studied and the result shows that the tunnelling rate of such a black hole is relevant to Bekenstein-Hawking entropy and that the obtained radiation spectrum is not pure thermal.
Static configurations and evolution of higher dimensional brane-dilaton black hole system
Nakonieczna, Anna; Nakonieczny, Łukasz; Moderski, Rafaƚ; Rogatko, Marek
2016-12-01
Static configurations and a dynamical evolution of the system composed of a higher-dimensional spherically symmetric dilaton black hole and the Dirac-Goto-Nambu brane were investigated. The studies were conducted for three values of the dilaton coupling constant, describing the uncoupled case, the low-energy limit of the string theory and dimensionally reduced Klein-Kaluza theories. When the black hole is nonextremal, two types of static configurations are observed, a brane which intersects the black hole horizon and a brane not having any common points with the accompanying black hole. As the number of spacetime dimensions increases, the brane bend in the vicinity of the black hole disappears closer to its horizon. Dynamical evolution of the system results in an expulsion of the black hole from the brane. It proceeds faster for bigger values of the bulk spacetime dimension and thicker branes. The value of the dilatonic coupling constant does not influence neither the static configurations nor the dynamical behavior of the examined nonextremal system. In the extremal dilaton black hole case one obtains expulsion of the brane which is independent on the spacetime dimensionality and the value of the coupling constant. Dynamical studies of the configurations in the extremal case reveal that the course of evolution of the system is similar to the nonextremal one, except for a slightly earlier expulsion of the black hole from the brane.
Fermionic greybody factors of two and five-dimensional dilatonic black holes
Energy Technology Data Exchange (ETDEWEB)
Becar, Ramon [Universidad Catolica de Temuco, Departamento de Ciencias Matematicas y Fisicas, Temuco (Chile); Gonzalez, P.A. [Universidad Diego Portales, Facultad de Ingenieria, Santiago (Chile); Vasquez, Yerko [Universidad de La Serena, Departamento de Fisica, Facultad de Ciencias, La Serena (Chile)
2014-08-15
We study fermionic perturbations in the background of a two and five-dimensional dilatonic black holes. Then, we compute the reflection and transmission coefficients and the absorption cross section for fermionic fields, and we show numerically that the absorption cross section vanishes in the low and high frequency limit. Also we find that beyond a certain value of the horizon radius r{sub 0} the absorption cross section for five-dimensional dilatonic black hole is constant. Besides, we have find that the absorption cross section decreases for higher angular momentum, and it decreases when the mass of the fermionic field increases. (orig.)
An alternative perspective to observe the critical phenomena of dilaton AdS black holes
Mo, Jie-Xiong
2016-01-01
The critical phenomena of dilaton AdS black holes are probed from a totally different perspective other than the $P-v$ criticality and the $q-U$ criticality discussed in the former literature. We investigate not only the two point correlation function but also the entanglement entropy of dilaton AdS black holes. We achieve this goal by solving the equation of motion constrained by the boundary condition numerically and we concentrate on $\\delta L$ and $\\delta S$ which have been regularized by subtracting the terms in pure AdS with the same boundary region. For both the two point correlation function and the entanglement entropy, we consider $4\\times2\\times2=16$ cases due to different choices of parameters. The van der Waals like behavior can be clearly witnessed from all the $T-\\delta L$ ($T-\\delta S$) graphs for $q
Supersymmetric black holes in 2D dilaton supergravity: baldness and extremality
Energy Technology Data Exchange (ETDEWEB)
Bergamin, L; Grumiller, D; Kummer, W [Institut fuer Theoretische Physik, Technische Universitaet Wien, Wiedner Hauptstr. 8-10, A-1040 Vienna (Austria)
2004-03-26
We present a systematic discussion of supersymmetric solutions of 2D dilaton supergravity. In particular those solutions which retain at least half of the supersymmetries are ground states with respect to the bosonic Casimir function (essentially the ADM mass). Nevertheless, by tuning the prepotential appropriately, black-hole solutions may emerge with an arbitrary number of Killing horizons. The absence of dilatino and gravitino hair is proved. Moreover, the impossibility of supersymmetric dS ground states and of nonextremal black holes is confirmed, even in the presence of a dilaton. In these derivations, knowledge of the general analytic solution of 2D dilaton supergravity plays an important role. The latter result is addressed in the more general context of gPSMs which have no supergravity interpretation. Finally it is demonstrated that the inclusion of non-minimally coupled matter, a step which is already nontrivial by itself, does not change these features in an essential way.
The entropy of Garfinkle-Horne dilaton black hole due to arbitrary spin fields
Institute of Scientific and Technical Information of China (English)
SHEN; Yougen(沈有根)
2002-01-01
Using the membrane model which is based on brick wall model, we calculated the free energy and entropy of Garfinkle-Horne dilatonic black hole due to arbitrary spin fields. The result shows that the entropy of scalar field and the entropy of Fermionic field have similar formulas. There is only a coefficient between them.
Supersymmetric black holes are extremal and bald in 2D dilaton supergravity
Bergamin, L; Kummer, Wolfgang
2004-01-01
We prove that solutions of 2D dilaton supergravity respecting both supersymmetries have to belong to the rather trivial class of constant dilaton vacua. Then it is shown that solutions which retain at least half of the supersymmetries are ground states with respect to the bosonic Casimir function -- in physical terms, the ADM mass has to vanish, whenever this notion is meaningful. Nevertheless, by tuning the prepotential appropriately, black hole solutions may emerge in such ground states with an arbitrary number of (Killing) horizons. Exploiting supersymmetric obstructions for bosonic quantities it is proven that all horizons have to be extremal. In these derivations the knowledge of the general analytic solution of 2D dilaton supergravity plays an important role. Finally it is demonstrated that the inclusion of non-minimally coupled matter, a step which is already nontrivial by itself, does not change these features in an essential way. As byproducts we notice the impossibility of a supersymmetric dS ground...
Static configurations and evolution of higher dimensional brane-dilaton black hole system
Nakonieczna, Anna; Moderski, Rafał; Rogatko, Marek
2016-01-01
Static configurations and a dynamical evolution of the system composed of a higher-dimensional spherically symmetric dilaton black hole and the Dirac-Goto-Nambu brane were investigated. The studies were conducted for three values of the dilaton coupling constant, describing the uncoupled case, the low-energy limit of the string theory and dimensionally reduced Klein-Kaluza theories. When the black hole is nonextremal, two types of static configurations are observed, a brane which intersects the black hole horizon and a brane not having any common points with the accompanying black hole. As the number of spacetime dimensions increases, the brane bend in the vicinity of the black hole disappears closer to its horizon. Dynamical evolution of the system results in an expulsion of the black hole from the brane. It proceeds faster for bigger values of the bulk spacetime dimension and thicker branes. The value of the dilatonic coupling constant does not influence neither the static configurations nor the dynamical b...
Hawking radiation for non asymptotically flat dilatonic black holes using gravitational anomaly
Fabris, J C
2012-01-01
The $d$-dimensional scalar field action may be reduced, in the background geometry of a black hole, to a 2-dimensional effective action. In the near horizon region, it appears a gravitational anomaly: the energy-momentum tensor of the scalar field is not conserved anymore. This anomaly is removed by introducing a term related to the Hawking temperature of the black hole. Even if the temperature term introduced is not covariant, a gauge transformation may restore the covariance. We apply this method to compute the temperature of the black hole of the dilatonic non asymptotically flat black holes. We compare the results with those obtained through other methods.
Phase transition for black holes in Dilatonic Einstein-Gauss-Bonnet theory of gravitation
Khimphun, Sunly; Lee, Wonwoo
2016-01-01
We study the thermodynamic properties of a black hole and the Hawking-Page phase transition in the asymptotically anti-de Sitter spacetime in the Dilatonic Einstein-Gauss-Bonnet theory of gravitation. We show how the higher-order curvature terms can influence both the thermodynamic properties and the phase transition. We evaluate both heat capacity and free energy difference to determine the local and global thermodynamic stabilities, respectively. We show that the phase transition occurs from the thermal anti-de Sitter to a small spherical black hole geometry and occurs to a large hyperbolic black hole geometry in the (Dilatonic) Einstein-Gauss-Bonnet theory of gravitation unlike those in Einstein's theory of gravitation.
Phase transition for black holes in dilatonic Einstein-Gauss-Bonnet theory of gravitation
Khimphun, Sunly; Lee, Bum-Hoon; Lee, Wonwoo
2016-11-01
We study the thermodynamic properties of a black hole and the Hawking-Page phase transition in the asymptotically anti-de Sitter spacetime in the dilatonic Einstein-Gauss-Bonnet theory of gravitation. We show how the higher-order curvature terms can influence both the thermodynamic properties and the phase transition. We evaluate both heat capacity and free energy difference to determine the local and global thermodynamic stabilities, respectively. We find that the phase transition occurs from the thermal anti-de Sitter to a small spherical black hole geometry and occurs to a hyperbolic black hole geometry in the (dilatonic) Einstein-Gauss-Bonnet theory of gravitation unlike those in Einstein's theory of gravitation.
Energy and angular momentum of dilaton black holes
Directory of Open Access Journals (Sweden)
Marcelo Samuel Berman
2008-01-01
Full Text Available Dando seguimiento a un art culo previo, revisamos los resultados para la energ a y momento angular de un hoyo negro de Kerr-Newman, y extendemos el c alculo para el caso de un dilaton en rotaci on, obtenido a partir del modelo de Gar nkle et al. (1991, 1992. Mostramos que hay, en lo que se re ere solamente a la energ a y momento angular, una interacci on entre los campos, de forma que, el gravitacional y el electromagn etico pueden ser ocultados por la intensidad del campo escalar.
Dehghani, M. H.; Pourhasan, R.; Mann, R. B.
2011-01-01
We investigate modifications of the Lifshitz black hole solutions due to the presence of Maxwell charge in higher dimensions for arbitrary $z$ and any topology. We find that the behaviour of large black holes is insensitive to the topology of the solutions, whereas for small black holes significant differences emerge. We generalize a relation previously obtained for neutral Lifshitz black branes, and study more generally the thermodynamic relationship between energy, entropy, and chemical pot...
The near-horizon geometry of dilaton-axion black holes
Clément, G
2001-01-01
Static black holes of dilaton-axion gravity become singular in the extreme limit, which prevents a direct determination of their near-horizon geometry. This is addressed by first taking the near-horizon limit of extreme rotating NUT-less black holes, and then going to the static limit. The resulting four-dimensional geometry may be lifted to a Bertotti-Robinson-like solution of six-dimensional vacuum gravity, which also gives the near-horizon geometry of extreme Kaluza-Klein black holes in five dimensions.
Hawking radiation for non-asymptotically flat dilatonic black holes using gravitational anomaly
Energy Technology Data Exchange (ETDEWEB)
Fabris, J.C. [Universidade Federal do Espirito Santo, Departamento de Fisica, Vitoria, Espirito Santo (Brazil); Marques, G.T. [Universidade Federal Rural da Amazonia-Brazil, ICIBE-LASIC, Belem, Para (Brazil)
2012-12-15
The d-dimensional scalar field action may be reduced, in the background geometry of a black hole, to a two-dimensional effective action. In the near-horizon region, it appears a gravitational anomaly: the energy-momentum tensor of the scalar field is not conserved anymore. This anomaly is removed by introducing a term related to the Hawking temperature of the black hole. Even if the temperature term introduced is not covariant, a gauge transformation may restore the covariance. We apply this method to compute the temperature of the dilatonic non-asymptotically flat black holes. We compare the results with those obtained through other methods. (orig.)
Flathmann, Kai
2015-01-01
In this article we study the geodesic motion of test particles and light in the Einstein-Maxwell-Dilaton-Axion black hole spacetime. We derive the equations of motion and present their solutions in terms of the Weierstra{\\ss} $\\wp$-, $\\sigma$- and $\\zeta$-functions. With the help of parametric diagrams and effective potentials we analyze the geodesic motion and give a list of all possible orbit types.
Hawking radiation from the dilaton-(anti) de Sitter black hole via covariant anomaly
Institute of Scientific and Technical Information of China (English)
Han Yi-Wen; Bao Zhi-Qing; Hong Yun
2009-01-01
Adopting the anomaly cancellation method, initiated by Robinson and Wilczek recently, this paper discusses Hawking radiation from the dilaton-(anti) de Sitter black hole. To save the underlying gauge and general covariance, it introduces covariant fluxes of gauge and energy-momentum tensor to cancel the gauge and gravitational anomalies. The result shows that the introduced compensating fluxes are equivalent to those of a 2-dimensional blackbody radiation at Hawking temperature with appropriate chemical potential.
Dyonic branes and linear dilaton background
Clément, G; Leygnac, C; Orlov, D; Clement, Gerard; Gal'tsov, Dmitri; Leygnac, Cedric; Orlov, Dmitri
2006-01-01
We study dyonic solutions to the gravity-dilaton-antisymmetric form equations with the goal of identifying new $p$-brane solutions on the fluxed linear dilaton background. Starting with the generic solutions constructed by reducing the system to decoupled Liouville equations for certain values of parameters, we identify the most general solution whose singularities are hidden behind a regular event horizon, and then explore the admissible asymptotic behaviors. In addition to known asymptotically flat dyonic branes, we find two classes of asymptotically non-flat solutions which can be interpreted as describing magnetically charged branes on the electrically charged linear dilaton background (and the $S$-dual configuration of electrically charged branes on the magnetically charged background), and uncharged black branes on the dyonically charged linear dilaton background. This interpretation is shown to be consistent with the first law of thermodynamics for the new solutions.
Quasilocal Energy for Static Charged Black Holes in String Theory
Institute of Scientific and Technical Information of China (English)
WANG Shi-Liang; JING Ji-Liang; WANG Yong-Jiu
2001-01-01
The Brown-York quasilocal energies of some static charged dilaton black holes are calculated, and then the validity of Martinez's conjecture is explored in string theory. It is shown that the energy is positive and monotonically decreases to the ADM mass at spatial infinity, and the conjecture that the Brown-York quasilocal energy at the outer horizon of black hole reduces to twice of its irreducible mass is still applicable for the static charged black holes in string theory. The result is different from Bose-Naing's one.``
Charged Stringy Black Holes With Non-Abelian Hair
Donets, E E
1993-01-01
Static spherically symmetric asymptotically flat charged black hole solutions are constructed within the magnetic SU(3) sector of the 4-dimensional heterotic string effective action. They possess non-abelian hair in addition to the Coulomb magnetic field and are qualitatively similar to the Einstein-Yang-Mills colored SU(3) black holes except for the extremal case. In the extremality limit the horizon shrinks and the resulting geometry around the origin coincides with that of an extremal abelian dilatonic black hole with magnetic charge. Non-abelian hair exibits then typical sphaleron structure.
Massless black holes and charged wormholes in string theory
Goulart, Prieslei
2016-01-01
We present the zero mass black holes and charged Einstein-Rosen bridges (wormholes) that arise from the five parameters dyonic black hole solution of the Einstein-Maxwell-dilaton theory. These massless black holes exist individually in spacetime, different from the known massless solutions which come in pairs with opposite signs for their masses. By imposing appropriate boundary conditions the massless solution can be nonextremal, extremal or a naked singularity. The nonextremal and extremal massless solutions allow the bridge construction, and from them we obtain the first analytical charged Einstein-Rosen bridge satisfying the null energy condition ever found.
(Anti)evaporation of Dyonic Black Holes in string-inspired dilaton $f(R)$-gravity
Addazi, Andrea
2016-01-01
We discuss dyonic black hole solutions in the case of $f(R)$-gravity coupled with a dilaton and two gauge bosons. The study of such a model is highly motivated from string theory. Our Black Hole solutions are extensions of the one firstly studied by Kallosh, Linde, Ort\\'in, Peet and Van Proyen (KLOPV) in [arXiv:hep-th/9205027]. We will show that extreme solutions are unstable. In particular, these solutions have Bousso-Hawking-Nojiri-Odintsov (anti)evaporation instabilities.
Exact solutions to the geodesic equations of linear dilaton black holes
Hamo, A H H
2015-01-01
In this paper, we analyze the geodesics of the 4-dimensional ($4D$) linear dilaton black hole (LDBH) spacetime, which is an exact solution to the Einstein-Maxwell-Dilaton (EMD) theory. LDBHs have non-asymptotically flat (NAF) geometry, and their Hawking radiation is an isothermal process. The geodesics motions of the test particles are studied via the standard Lagrangian method. After obtaining the Euler-Lagrange (EL) equations, we show that exact analytical solutions to the radial and angular geodesic equations can be obtained. In particular, it is shown that one of the possible solutions for the radial trajectories can be given in terms of the WeierstrassP-function ($\\wp$-function), which is an elliptic-type special function.
Babichev, Eugeny; Charmousis, Christos; Hassaine, Mokhtar
2015-05-01
We consider an Abelian gauge field coupled to a particular truncation of Horndeski theory. The Galileon field has translation symmetry and couples non minimally both to the metric and the gauge field. When the gauge-scalar coupling is zero the gauge field reduces to a standard Maxwell field. By taking into account the symmetries of the action, we construct charged black hole solutions. Allowing the scalar field to softly break symmetries of spacetime we construct black holes where the scalar field is regular on the black hole event horizon. Some of these solutions can be interpreted as the equivalent of Reissner-Nordstrom black holes of scalar tensor theories with a non trivial scalar field. A self tuning black hole solution found previously is extended to the presence of dyonic charge without affecting whatsoever the self tuning of a large positive cosmological constant. Finally, for a general shift invariant scalar tensor theory we demonstrate that the scalar field Ansatz and method we employ are mathematically compatible with the field equations. This opens up the possibility for novel searches of hairy black holes in a far more general setting of Horndeski theory.
Asymptotic Quasinormal Modes of the Garfinkle-Horowitz-Strominger Dilaton Black Hole
Institute of Scientific and Technical Information of China (English)
CHEN Song-Bai; JING Ji-Liang
2004-01-01
@@ Using the monodromy technique proposed by Motl and Neitzke (Adv. Theor. Math. Phys. 7 (2003)307), we investigate the analytic forms of the asymptotic quasinormal frequencies for the massless scalar perturbation in the Garfinkle-Horowitz-Strominger dilaton spacetime. We find that the real parts of the quasinormal frequencies are TH ln 3. This agrees with that of the quasinormal modes in the Schwarzschild spacetime. Our result implies that Hod's conjecture about ln3 is still valid for the black hole spacetime in the string theory.
Phase structures of 4D stringy charged black holes in canonical ensemble
Jia, Qiang; Tan, Xiao-Jun
2016-01-01
We study the thermodynamics and phase structures of the asymptotically flat dilatonic black holes in 4 dimensions, placed in a cavity {\\it a la} York, in string theory for an arbitrary dilaton coupling. We consider these charged black systems in canonical ensemble for which the temperature at the wall of and the charge inside the cavity are fixed. We find that the dilaton coupling plays the key role in the underlying phase structures. The connection of these black holes to higher dimensional brane systems via diagonal (double) and/or direct dimensional reductions indicates that the phase structures of the former may exhaust all possible ones of the latter, which are more difficult to study, under conditions of similar settings. Our study also shows that a diagonal (double) dimensional reduction preserves the underlying phase structure while a direct dimensional reduction has the potential to change it.
Black holes in Einstein-Gau\\ss -Bonnet-dilaton theory
Blázquez-Salcedo, Jose Luis; Ferrari, Valeria; Gualtieri, Leonardo; Kanti, Panagiota; Khoo, Fech Scen; Kleihaus, Burkhard; Kunz, Jutta; Macedo, Caio F B; Mojica, Sindy; Pani, Paolo; Radu, Eugen
2016-01-01
Generalizations of the Schwarzschild and Kerr black holes are discussed in an astrophysically viable generalized theory of gravity, which includes higher curvature corrections in the form of the Gauss-Bonnet term, coupled to a dilaton. The angular momentum of these black holes can slightly exceed the Kerr bound. The location and the orbital frequency of particles in their innermost stable circular orbits can deviate significantly from the respective Kerr values. Study of the quasinormal modes of the static black holes gives strong evidence that they are mode stable against polar and axial perturbations. Future gravitational wave observations should improve the current bound on the Gauss-Bonnet coupling constant, based on observations of the low-mass x-ray binary A 0620-00.
Dias, O J C; Dias, Oscar J. C.; Lemos, Jose' P. S.
2001-01-01
We obtain static and rotating electrically charged black holes of a Einstein-Maxwell-Dilaton theory of the Brans-Dicke type in (2+1)-dimensions. The theory is specified by three fields, the dilaton, the graviton and the electromagnetic field, and two parameters, the cosmological constant and the Brans-Dicke parameter. It contains eight different cases, of which one distinguishes as special cases, string theory, general relativity and a theory equivalent to four dimensional general relativity with one Killing vector. We find the ADM mass, angular momentum, electric charge and dilaton charge and compute the Hawking temperature of the solutions. Causal structure and geodesic motion of null and timelike particles in the black hole geometries are studied in detail.
Nashed, Gamal Gergess Lamee
2008-01-01
We apply the energy-momentum tensor to calculate energy, momentum and angular-momentum of two different tetrad fields. This tensor is coordinate independent of the gravitational field established in the Hamiltonian structure of the teleparallel equivalent of general relativity (TEGR). The spacetime of these tetrad fields is the charged dilaton. Our results show that the energy associated with one of these tetrad fields is consistent, while the other one does not show this consistency. Therefore, we use the regularized expression of the gravitational energy-momentum tensor of the TEGR. We investigate the energy within the external event horizon using the definition of the gravitational energy-momentum.
Babichev, Eugeny; Hassaine, Mokhtar
2015-01-01
We consider an Abelian gauge field coupled to a particular truncation of Horndeski theory. The Galileon field has translation symmetry and couples non minimally both to the metric and the gauge field. When the gauge-scalar coupling is zero the gauge field reduces to a standard Maxwell field. By taking into account the symmetries of the action, we construct charged black hole solutions. Allowing the scalar field to softly break symmetries of spacetime we construct black holes where the scalar field is regular on the black hole event horizon. Some of these solutions can be interpreted as the equivalent of Reissner-Nordstrom black holes of scalar tensor theories with a non trivial scalar field. A self tuning black hole solution found previously is extended to the presence of dyonic charge without affecting whatsoever the self tuning of a large positive cosmological constant. Finally, for a general shift invariant scalar tensor theory we demonstrate that the scalar field Ansatz and method we employ are mathematic...
Energy Technology Data Exchange (ETDEWEB)
Hendi, S.H. [Shiraz University, Physics Department and Biruni Observatory, College of Sciences, Shiraz (Iran, Islamic Republic of); Research Institute for Astronomy and Astrophysics of Maragha (RIAAM), P. O. Box 55134-441, Maragha (Iran, Islamic Republic of); Tad, R.M.; Armanfard, Z.; Talezadeh, M.S. [Shiraz University, Physics Department and Biruni Observatory, College of Sciences, Shiraz (Iran, Islamic Republic of)
2016-05-15
Motivated by a thermodynamic analogy of black holes and Van der Waals liquid/gas systems, in this paper, we study P-V criticality of both dilatonic Born-Infeld black holes and their conformal solutions, Brans-Dicke-Born-Infeld solutions. Due to the conformal constraint, we have to neglect the old Lagrangian of dilatonic Born-Infeld theory and its black hole solutions, and introduce a new one. We obtain spherically symmetric nonlinearly charged black hole solutions in both Einstein and Jordan frames and then we calculate the related conserved and thermodynamic quantities. After that, we extend the phase space by considering the proportionality of the cosmological constant and thermodynamical pressure. We obtain critical values of the thermodynamic coordinates through numerical methods and plot the relevant P-V and G-T diagrams. Investigation of the mentioned diagrams helps us to study the thermodynamical phase transition. We also analyze the effects of varying different parameters on the phase transition of black holes. (orig.)
Thermodynamics of phantom black holes in Einstein-Maxwell-dilaton theory
Rodrigues, Manuel E.; Oporto, Zui A. A.
2012-05-01
A thermodynamic analysis of the black hole solutions coming from the Einstein-Maxwell-dilaton theory in 4D is done. By considering the canonical and grand-canonical ensemble, we apply standard method as well as a recent method known as geometrothermodynamics. We are particularly interested in the characteristics of the so called phantom black hole solutions. We will analyze the thermodynamics of these solutions, the points of phase transition and their extremal limit. The thermodynamic stability is also analyzed. We obtain a mismatch between the results of the geometrothermodynamics method when compared with the ones obtained by the specific heat, revealing a weakness of the method, as well as possible limitations of its applicability to very pathological thermodynamic systems. We also found that normal and phantom solutions are locally and globally unstable, except for certain values of the coupled constant of the Einstein-Maxwell-dilaton action. We also show that the anti-Reissner-Nordstrom solution does not possess extremal limit nor phase transition points, contrary to the Reissner-Nordstrom case.
"Triangular" extremal dilatonic dyons
Gal'tsov, Dmitri; Orlov, Dmitri
2014-01-01
Explicit dyonic dilaton black holes of the four-dimensional Einstein-Maxwell-dilaton theory are known only for two particular values of the dilaton coupling constant $a =1,\\sqrt{3}$, while for other $a$ numerical evidence was presented earlier about existence of extremal dyons in theories with the discrete sequence of dilaton couplings $a=\\sqrt{n(n+1)/2}$ with integer $n$. Apart from the lower members $n=1,\\,2$, this family of theories does not have motivation from supersymmetry or higher dimensions, and so far the above quantization rule has not been derived analytically. We fill this gap showing that this rule follows from analyticity of the dilaton at the $AdS_2\\times S^2$ event horizon with $n$ being the leading dilaton power in the series expansion. We also present generalization for asymptotically anti-de Sitter dyonic black holes with spherical, plane and hyperbolic topology of the horizon.
Null Geodesics in a Magnetically Charged Stringy Black Hole Spacetime
Kuniyal, Ravi Shankar; Nandan, Hemwati; Purohit, K D
2015-01-01
We study the geodesic motion of massless test particles in the background of a magnetic charged black hole spacetime in four dimensions in dilaton-Maxwell gravity. The behaviour of effective potential in view of the different values of black hole parameters is analysed in the equatorial plane. The possible orbits for null geodesics are also discussed in detail in view of the different values of the impact parameter. We have also calculated the frequency shift of photons in this spacetime. The results obtained are then compared with those for the electrically charged stringy black hole spacetime and the Schwarzschild black hole spacetime. It is observed that there exists no stable circular orbit outside the event horizon for massless test particles.
First Quantum Correction to Dirac Entropy for Rotating U(1)(×)U(1) Dilaton Black Hole
Institute of Scientific and Technical Information of China (English)
高长军; 沈有根
2002-01-01
The first quantum correction to rotating U(1)(×)U(1) dilaton black hole entropy is calculated by using the improved brick-wall model. We propose not to consider the superradiant mode for the reason that fermion fields do not display superradiance. We found that the nonsuperradiant mode does contribute exactly the first quantum correction to the non-extreme black hole entropy. Moreover, our cut-off Newman-Penrose e which does not require an angular cut-off is independent of angle. As for the extreme black hole, we found that its entropy is zero.
When Charged Black Holes Merge
Kohler, Susanna
2016-08-01
Most theoretical models assume that black holes arent charged. But a new study shows that mergers of charged black holes could explain a variety of astrophysical phenomena, from fast radio bursts to gamma-ray bursts.No HairThe black hole no hair theorem states that all black holes can be described by just three things: their mass, their spin, and their charge. Masses and spins have been observed and measured, but weve never measured the charge of a black hole and its widely believed that real black holes dont actually have any charge.That said, weve also never shown that black holes dont have charge, or set any upper limits on the charge that they might have. So lets suppose, for a moment, that its possible for a black hole to be charged. How might that affect what we know about the merger of two black holes? A recent theoretical study by Bing Zhang (University of Nevada, Las Vegas) examines this question.Intensity profile of a fast radio burst, a sudden burst of radio emission that lasts only a few milliseconds. [Swinburne Astronomy Productions]Driving TransientsZhangs work envisions a pair of black holes in a binary system. He argues that if just one of the black holes carries charge possibly retained by a rotating magnetosphere then it may be possible for the system to produce an electromagnetic signal that could accompany gravitational waves, such as a fast radio burst or a gamma-ray burst!In Zhangs model, the inspiral of the two black holes generates a global magnetic dipole thats perpendicular to the plane of the binarys orbit. The magnetic flux increases rapidly as the separation between the black holes decreases, generating an increasingly powerful magnetic wind. This wind, in turn, can give rise to a fast radio burst or a gamma-ray burst, depending on the value of the black holes charge.Artists illustration of a short gamma-ray burst, thought to be caused by the merger of two compact objects. [ESO/A. Roquette]Zhang calculates lower limits on the charge
Black Branes as Piezoelectrics
Armas, Jay; Obers, Niels A
2012-01-01
We find a realization of linear electroelasticity theory in gravitational physics by uncovering a new response coefficient of charged black branes, exhibiting their piezoelectric behavior. Taking charged dilatonic black strings as an example and using the blackfold approach we measure their elastic and piezolectric moduli. We also use our results to draw predictions about the equilibrium condition of charged dilatonic black rings in dimensions higher than six.
Black branes as piezoelectrics.
Armas, Jay; Gath, Jakob; Obers, Niels A
2012-12-14
We find a realization of linear electroelasticity theory in gravitational physics by uncovering a new response coefficient of charged black branes, exhibiting their piezoelectric behavior. Taking charged dilatonic black strings as an example and using the blackfold approach we measure their elastic and piezolectric moduli. We also use our results to draw predictions about the equilibrium condition of charged dilatonic black rings in dimensions higher than six.
Blázquez-Salcedo, Jose Luis
2016-01-01
Gravitational waves emitted by distorted black holes---such as those arising from the coalescence of two neutron stars or black holes---carry not only information about the corresponding spacetime but also about the underlying theory of gravity. Although general relativity remains the simplest, most elegant and viable theory of gravitation, there are generic and robust arguments indicating that it is not the ultimate description of the gravitational universe. Here we focus on a particularly appealing extension of general relativity, which corrects Einstein's theory through the addition of terms which are second order in curvature: the topological Gauss-Bonnet invariant coupled to a dilaton. We study gravitational-wave emission from black holes in this theory, and (i) find strong evidence that black holes are linearly (mode) stable against both axial and polar perturbations; (ii) discuss how the quasinormal modes of black holes can be excited during collisions involving black holes, and finally (iii) show that...
Harrison transformation and charged black objects in Kaluza-Klein theory
Kleihaus, Burkhard; Kunz, Jutta; Radu, Eugen; Stelea, Cristian
2009-09-01
We generate charged black brane solutions in D-dimensions in a theory of gravity coupled to a dilaton and an antisymmetric form, by using a Harrison-type transformation. The seed vacuum solutions that we use correspond to uplifted Kaluza-Klein black strings and black holes in (D-p)-dimensions. A generalization of the Marolf-Mann quasilocal formalism to the Kaluza-Klein theory is also presented, the global charges of the black objects being computed in this way. We argue that the thermodynamics of the charged solutions can be derived from that of the vacuum configurations. Our results show that all charged Kaluza-Klein solutions constructed by means of Harrison transformations are thermodynamically unstable in a grand canonical ensemble. The general formalism is applied to the case of nonuniform black strings and caged black hole solutions in D = 5,6 Einstein-Maxwell-dilaton gravity, whose geometrical properties and thermodynamics are discussed. We argue that the topology changing transition scenario, which was previously proposed in the vacuum case, also holds in this case. Spinning generalizations of the charged black strings are constructed in six dimensions in the slowly rotating limit. We find that the gyromagnetic ratio of these solutions possesses a nontrivial dependence on the nonuniformity parameter.
Magnetically-charged black branes and viscosity/entropy ratios
Liu, Hai-Shan; Lü, H.; Pope, C. N.
2016-12-01
We consider asymptotically-AdS n-dimensional black brane solutions in a theory of gravity coupled to a set of N p-form field strengths, in which the field strengths carry magnetic charges. For appropriately chosen charges, the metrics are isotropic in the ( n - 2) transverse directions. However, in general the field strength configurations break the full Euclidean symmetry of the ( n - 2)-dimensional transverse space, and the shear viscosity tensor in the dual theory is no longer isotropic. We study the linearised equations for transverse traceless metric perturbations in these backgrounds, and by employing the Kubo formula we obtain expressions for the ratios η/S of the shear viscosity components divided by the entropy density. We find that the KSS bound on the ratios η/S is generally violated in these solutions. We also extend the discussion by including a dilatonic scalar field in the theory, leading to solutions that are asymptotically Lifshitz with hyperscaling violation.
Harrison transformation and charged black objects in Kaluza-Klein theory
Kleihaus, Burkhard; Radu, Eugen; Stelea, Cristian
2009-01-01
We generate charged black brane solutions in $D-$dimensions in a theory of gravity coupled to a dilaton and an antisymmetric form, by using a Harrison-type transformation. The seed vacuum solutions that we use correspond to uplifted Kaluza-Klein black strings and black holes in $(D-p)$-dimensions. A generalization of the Marolf-Mann quasilocal formalism to the Kaluza-Klein theory is also presented, the global charges of the black objects being computed in this way. We argue that the thermodynamics of the charged solutions can be derived from that of the vacuum configurations. Our results show that all charged Kaluza-Klein solutions constructed by means of Harrison transformations are thermodynamically unstable in a grand canonical ensemble. The general formalism is applied to the case of nonuniform black strings and caged black hole solutions in $D=5, 6$ Einstein-Maxwell-dilaton gravity, whose geometrical properties and thermodynamics are discussed. We argue that the topology changing transition scenario, whi...
Blázquez-Salcedo, Jose Luis; Macedo, Caio F. B.; Cardoso, Vitor; Ferrari, Valeria; Gualtieri, Leonardo; Khoo, Fech Scen; Kunz, Jutta; Pani, Paolo
2016-11-01
Gravitational waves emitted by distorted black holes—such as those arising from the coalescence of two neutron stars or black holes—carry not only information about the corresponding spacetime but also about the underlying theory of gravity. Although general relativity remains the simplest, most elegant, and viable theory of gravitation, there are generic and robust arguments indicating that it is not the ultimate description of the gravitational universe. Here, we focus on a particularly appealing extension of general relativity, which corrects Einstein's theory through the addition of terms which are second order in curvature: the topological Gauss-Bonnet invariant coupled to a dilaton. We study gravitational-wave emission from black holes in this theory and (i) find strong evidence that black holes are linearly (mode) stable against both axial and polar perturbations, (ii) discuss how the quasinormal modes of black holes can be excited during collisions involving black holes, and finally (iii) show that future ringdown detections with a large signal-to-noise ratio would improve current constraints on the coupling parameter of the theory.
Energy Technology Data Exchange (ETDEWEB)
García-Diaz, Alberto A. [Departamento de Física, Centro de Investigación y de Estudios Avanzados del IPN, Apdo. Postal 14-740, 07000 México DF, México. and Departamento de Física, Universidad Autónoma Metropolitana-Iztapalapa, Apdo. (Mexico)
2014-01-14
Using the Schwarzschild coordinate frame for a static cyclic symmetric metric in 2+1 gravity coupled minimally to a dilaton logarithmically depending on the radial coordinate in the presence of an exponential potential, by solving first order linear Einstein equations, the general solution is derived and it is identified with the Chan–Mann dilaton solution. In these coordinates, a new stationary dilaton solution is obtained; it does not allow for a de Sitter–Anti-de Sitter limit at spatial infinity, where its structural functions increase indefinitely. On the other hand, it is horizonless and allows for a naked singularity at the origin of coordinates; moreover, one can identify at a large radial coordinate a (quasi-local) mass parameter and in the whole space a constant angular momentum. Via a general SL(2,R)–transformation, applied on the static cyclic symmetric metric, a family of stationary dilaton solutions has been generated. A particular SL(2,R)–transformation is identified, which gives rise to the rotating Chan–Mann dilaton solution. All the exhibited solutions have been characterized by their quasi-local energy, mass, and momentum through their series expansions at spatial infinity. The algebraic structure of the Ricci–energy-momentum, and Cotton tensors is given explicitly.
Zangeneh, M Kord; Mehdizadeh, M R; Wang, B; Sheykhi, A
2016-01-01
In this paper, we first obtain the ($n+1$)-dimensional dilaton-Lifshitz black hole (BH) solutions in the presence of Born-Infeld (BI) electrodynamics. We find that there are two different solutions for $z=n+1$ and $z\
Maselli, Andrea; Pani, Paolo; Stella, Luigi; Ferrari, Valeria
2014-01-01
Quasi-Periodic Oscillations (QPOs) observed in the X-ray flux emitted by accreting black holes, are associated to phenomena occurring near the horizon. Future very large area X-ray instruments will be able to measure QPO frequencies with very high precision, thus probing this strong-field region. By using the relativistic precession model, we show the way in which QPO frequencies could be used to test general relativity against those alternative theories of gravity which predict deviations from the classical theory in the strong-field regime. We consider one of the best motivated strong-curvature corrections to general relativity, namely the Einstein-Dilaton-Gauss-Bonnet theory, and show that a detection of QPOs with the expected sensitivity of the proposed ESA M-class mission LOFT would set the most stringent constraints on the parameter space of this theory.
Diffeomorphisms, noether charges and canonical formalism in 2D dilaton gravity
Navarro-Salas, J; Talavera, C F; Navarro-Salas, J; Navarro, M; Talavera, C F
1994-01-01
We carry out a parallel study of the covariant phase space and the conservation laws of local symmetries in two-dimensional dilaton gravity. Our analysis is based on the fact that the Lagrangian can be brought to a form that vanishes on-shell giving rise to a well-defined covariant potential for the symplectic current. We explicitly compute the symplectic structure and its potential and show that the requirement to be finite and independent of the Cauchy surface restricts the asymptotic symmetries.
Charged Black Holes in New Massive Gravity
Ghodsi, Ahmad; Moghadassi, Mohammad
2010-01-01
We construct charged black hole solutions to three-dimensional New Massive Gravity (NMG), by adding electromagnetic Maxwell and Chern-Simons actions. We find charged black holes in the form of warped AdS_3 and "log" solutions in specific critical point. The entropy, mass and angular momentum of these black holes are computed.
Mo, Jie-Xiong; Xu, Xiao-Bao
2016-01-01
The effects of power-law Maxwell field on the Van der Waals like phase transition of higher-dimensional dilaton black holes are probed in detail. It is shown that the Smarr relation gains corrections due to the effects of both the power-law Maxwell field and the dilaton field while thermodynamic volume is exactly the same as that of Einstein-Maxwell-dilaton black holes. We successfully derive the analytic solutions of critical point and carry out some check to ensure that these critical quantities are positive. It is shown that the constraint on the parameters turns out to be $0<\\alpha^2<1$, which is more tighter than that in the non-extended phase space. It is also shown that these critical quantities and the ratio $P_cv_c/T_c$ are affected by the power-law Maxwell field. Moreover, critical exponents are found to coincide with those of other AdS black holes, showing the powerful influence of mean field theory.
Area-charge inequality for black holes
Dain, Sergio; Reiris, Martín
2011-01-01
The inequality between area and charge $A\\geq 4\\pi Q^2$ for dynamical black holes is proved. No symmetry assumption is made and charged matter fields are included. Extensions of this inequality are also proved for regions in the spacetime which are not necessarily black hole boundaries.
Charged black holes in phantom cosmology
Energy Technology Data Exchange (ETDEWEB)
Jamil, Mubasher; Qadir, Asghar; Rashid, Muneer Ahmad [National University of Sciences and Technology, Center for Advanced Mathematics and Physics, Rawalpindi (Pakistan)
2008-11-15
In the classical relativistic regime, the accretion of phantom-like dark energy onto a stationary black hole reduces the mass of the black hole. We have investigated the accretion of phantom energy onto a stationary charged black hole and have determined the condition under which this accretion is possible. This condition restricts the mass-to-charge ratio in a narrow range. This condition also challenges the validity of the cosmic-censorship conjecture since a naked singularity is eventually produced due to accretion of phantom energy onto black hole. (orig.)
Stealths on $(1+1)$-dimensional dilatonic gravity
Alvarez, Abigail; Cruz, Miguel; Rojas, Efraín; Saavedra, Joel
2016-01-01
We study gravitational stealth configurations emerging on a charged dilatonic $(1+1)$-D black hole spacetime. We accomplish this by considering the coupling of a non-minimally scalar field $\\phi$ and a self-interacting scalar field $\\Psi$ living in a $(1+1)$-D charged black hole background. In addition, the self-interacting potential for $\\Psi$ is obtained which exhibits transitions for some specific values of the non-minimal parameter. Atypically, we found that the solutions for these stealth scalar fields do not have a dependence on the temporal coordinate.
Energy Technology Data Exchange (ETDEWEB)
Herrera-Aguilar, Alfredo [Instituto de FIsica y Matematicas, Universidad Michoacana de San Nicolas de Hidalgo, Edificio C-3, Ciudad Universitaria, Morelia, Mich., CP 58040 (Mexico); Nowakowski, Marek [Departamento de FIsica, Universidad de los Andes, Cra. 1 No 18A-10, Santa Fe de Bogota (Colombia)
2004-02-21
Using the stationary formulation of the toroidally compactified heterotic string theory in terms of a pair of matrix Ernst potentials we consider the four-dimensional truncation of this theory with no U(1) vector fields excited. Imposing one timelike Killing vector permits us to express the stationary effective action as a model in which gravity is coupled to a matrix Ernst potential which, under certain parametrization, allows us to interpret the matter sector of this theory as a double Ernst system. We generate a web of string vacua which are related to each other via a set of discrete symmetries of the effective action (some of them involve S-duality transformations and possess non-perturbative character). Some physical implications of these discrete symmetries are analysed and we find that, in some particular cases, they relate rotating black holes coupled to a dilaton with no Kalb-Ramond field, static black holes with non-trivial dilaton and antisymmetric tensor fields, and rotating and static naked singularities. Further, by applying a nonlinear symmetry, namely, the so-called normalized Harrison transformation, on the seed field configurations corresponding to these neutral backgrounds, we recover the U(1){sup n} Abelian vector sector of the four-dimensional action of the heterotic string, charging in this way the double Ernst system which corresponds to each one of the neutral string vacua, i.e., the stationary and the static black holes and the naked singularities.
Generalised Smarr Formula and the Viscosity Bound for Einstein-Maxwell-Dilaton Black Holes
Liu, Hai-Shan; Pope, C N
2015-01-01
We study the shear viscosity to entropy ratio $\\eta/S$ in the boundary field theories dual to black hole backgrounds in theories of gravity coupled to a scalar field, and generalisations including a Maxwell field and non-minimal scalar couplings. Motivated by the observation in simple examples that the saturation of the $\\eta/S\\ge 1/(4\\pi)$ bound is correlated with the existence of a generalised Smarr relation for the planar black-hole solutions, we investigate this in detail for the general black-hole solutions in these theories, focusing especially on the cases where the scalar field plays a non-trivial role and gives rise to an additional parameter in the space of solutions. We find that a generalised Smarr relation holds in all cases, and in fact it can be viewed as the bulk gravity dual of the statement of the saturation of the viscosity to entropy bound. We obtain the generalised Smarr relation, whose existence depends upon a scaling symmetry of the planar black-hole solutions, by two different but rela...
On conserved charges and thermodynamics of the AdS$_{4}$ dyonic black hole
Cárdenas, Marcela; Matulich, Javier
2016-01-01
Four-dimensional gravity in the presence of a dilatonic scalar field and an Abelian gauge field is considered. This theory corresponds to the bosonic sector of a Kaluza-Klein dimensional reduction of eleven-dimensional supergravity which induces a determined self-interacting potential for the scalar field. We compute the conserved charges and carry out the thermodynamics of an anti-de Sitter (AdS) dyonic black hole solution recently proposed. The charges coming from symmetries of the action are computed by using the Regge-Teitelboim Hamiltonian approach. These correspond to the mass, which acquires contributions from the scalar field, and the electric charge. Integrability conditions are introduced because the scalar field leads to non-integrable terms in the variation of the mass. These conditions are generically solved by introducing boundary conditions that arbitrarily relates the leading and subleading terms of the scalar field fall-off. The Hamiltonian Euclidean action, computed in the grand canonical en...
Thermodynamics of phantom black holes in Einstein-Maxwell-Dilaton theory
Rodrigues, Manuel E
2012-01-01
A thermodynamic analysis of the black hole solutions coming from the Einstein-Maxwell-Dilation theory (EMD) is done. By consider the the canonical and grand-canonical ensemble, we apply standard methods as well as a recent method knowns as Geometrothermodynamics. We are particularly interested on the characteristics of the so called phantom black hole solutions. The thermodynamics of those solutions, point of phase transition and extremal limit are constructed, also the thermodynamic stability of the solutions is analysed. We obtain that the normal and phantoms cases are locally and globally unstable, unless for specific values of the parameter $\\gamma$, coming from the coupled constant $\\lambda$ of the EMD action. We shown that the anti-Reissner-Nordstrom case does not posses extremal limit nor a phase transition point, contrary to the Reissner-Nordstrom case.
Central charge for the Schwarzschild black hole
Ropotenko, K.
2016-12-01
Proceeding in exactly the same way as in the derivation of the temperature of a dual CFT for the extremal black hole in the Kerr/CFT correspondence, it is found that the temperature of a chiral, dual CFT for the Schwarzschild black hole is T = 1/2π. Comparing Cardy’s formula with the Bekenstein-Hawking entropy and using T, it is found that the central charge for the Schwarzschild black hole is of the form c = 12Jin, where Jin is the intrinsic angular momentum of the black hole, Jin = A/8πG. It is shown that the central charge for any four-dimensional (4D) extremal black hole is of the same form. The possible universality of this form is briefly discussed.
Charged black holes in colored Lifshitz spacetimes
Directory of Open Access Journals (Sweden)
Zhong-Ying Fan
2015-04-01
Full Text Available We consider Einstein gravities coupled to a cosmological constant and SU(2 Yang–Mills fields in four and five dimensions. We find that the theories admit colored Lifshitz solutions with dynamic exponents z>1. We study the wave equations of the SU(2 scalar triplet in the bulk, and find that the vacuum color modifies the scaling dimensions of the dual operators. We also introduce a Maxwell field and construct exact solutions of electrically-charged black holes that approach the D=4, z=3 and D=5, z=4 colored Lifshitz spacetimes. We derive the thermodynamical first law for general colored and charged Lifshitz black holes.
The Foaming Three-Charge Black Hole
Bena, Iosif; Wang, Chih-Wei; Nicholas P. Warner(Department of Physics and Astronomy, University of Southern California, Los Angeles, CA 90089, U.S.A.)
2006-01-01
We find a very large set of smooth horizonless geometries that have the same charges and angular momenta as the five-dimensional, maximally-spinning, three-charge, BPS black hole (J^2 = Q^3). Our solutions are constructed using a four-dimensional Gibbons-Hawking base space that has a very large number of two-cycles. The entropy of our solutions is proportional to Q^(1/2). In the same class of solutions we also find microstates corresponding to zero-entropy black rings, and these are related t...
Hydrodynamics of R-charged black holes
Son, D T; Son, Dam T.; Starinets, Andrei O.
2006-01-01
We consider hydrodynamics of N=4 supersymmetric SU(N_c) Yang-Mills plasma at a nonzero density of R-charge. In the regime of large N_c and large 't Hooft coupling the gravity dual description involves an asymptotically Anti- de Sitter five-dimensional charged black hole solution of Behrnd, Cvetic and Sabra. We compute the shear viscosity as a function of chemical potentials conjugated to the three U(1) \\subset SO(6)_R charges. The ratio of the shear viscosity to entropy density is independent of the chemical potentials and is equal to 1/4\\pi. For a single charge black hole we also compute the thermal conductivity, and investigate the critical behavior of the transport coefficients near the boundary of thermodynamic stability.
BSW process of the slowly evaporating charged black hole
Wang, Liancheng; He, Feng; Fu, Xiangyun
2015-01-01
In this paper, we study the BSW process of the slowly evaporating charged black hole. It can be found that the BSW process will also arise near black hole horizon when the evaporation of charged black hole is very slow. But now the background black hole does not have to be an extremal black hole, and it will be approximately an extremal black hole unless it is nearly a huge stationary black hole.
Extremal black holes in D=4 Gauss-Bonnet gravity
Chen, C M; Orlov, D G; Chen, Chiang-Mei; Galtsov, Dmitri V.; Orlov, Dmitry G.
2006-01-01
We show that four-dimensional Gauss-Bonnet gravity allows for asymptotically flat black hole solutions with a degenerate event horizon of the Reissner-Nordstrom type ($AdS_2\\times S^2$). Such black holes exist for the dilaton coupling constant within the interval $0\\leq a
Geodesics of Spherical Dilaton Spacetimes
Institute of Scientific and Technical Information of China (English)
ZENG Yi; L(U) Jun-Li; WANG Yong-Jiu
2006-01-01
The properties of spherical dilaton black hole spacetimes are investigated through a study of their geodesies. The closed and non-closed orbits of test particles are analysed using the effective potential and phase-plane method. The stability and types of orbits are determined in terms of the energy and angular momentum of the test particles. The conditions of the existence of circular orbits for a spherical dilaton spacetime with an arbitrary dilaton coupling constant a are obtained. The properties of the orbits and in particular the position of the innermost stable circular orbit are compared to those of the Reissner-Nordstrom spacetime. The circumferential radius of innermost stable circular orbit and the corresponding angular momentum of the test particles increase for a≠0.
Noether charge, black hole volume and complexity
Couch, Josiah; Nguyen, Phuc H
2016-01-01
In this paper, we study the physical significance of the thermodynamic volumes of black holes along two different, but complementary, directions. In the first half of the paper, we make use of the Iyer-Wald charge formalism to compute the volume of a particularly hairy black hole. Our computation clarifies and explains existing results, and serves as a prototype for computations of this kind for complicated black hole solutions. In the second half of the paper, we establish a connection between the extended thermodynamics and the Brown et al's "complexity=action" proposal. We show that, in a broad class of AdS black holes, the thermodynamic volume arises as the late-time rate of growth of the bulk action evaluated on the Wheeler-deWitt patch.
Retrolensing by a charged black hole
Tsukamoto, Naoki; Gong, Yungui
2017-03-01
Compact objects with a light sphere such as black holes and wormholes can reflect light rays like a mirror. This gravitational lensing phenomenon is called retrolensing and it is an interesting tool to survey dark and compact objects with a light sphere near the solar system. In this paper, we calculate the deflection angle analytically in the strong deflection limit in the Reissner-Nordström spacetime without Taylor expanding it in the power of the electric charge. Using the obtained deflection angle in the strong deflection limit, we investigate the retrolensing light curves and the separation of double images by the light sphere of Reissner-Nordström black holes.
Black hole horizons and quantum charged particles
Jaramillo, José Luis
2014-01-01
We point out a structural similarity between the characterization of black hole apparent horizons as stable marginally outer trapped surfaces (MOTS) and the quantum description of a non-relativistic charged particle moving in given magnetic and electric fields on a closed surface. Specifically, the spectral problem of the MOTS-stability operator corresponds to a stationary quantum particle with a formal fine-structure constant $\\alpha$ of negative sign. We discuss how such analogy enriches both problems, illustrating this with the insights into the MOTS-spectral problem gained from the analysis of the spectrum of the quantum charged particle Hamiltonian.
On conserved charges and thermodynamics of the AdS4 dyonic black hole
Cárdenas, Marcela; Fuentealba, Oscar; Matulich, Javier
2016-05-01
We consider four-dimensional gravity in the presence of a dilatonic scalar field and an Abelian gauge field. This theory corresponds to the bosonic sector of a Kaluza-Klein reduction of eleven-dimensional supergravity which induces a specific self-interacting potential for the scalar field. We compute the conserved charges and carry out the thermodynamics of an anti-de Sitter (AdS) dyonic black hole solution that was proposed recently. The charges coming from symmetries of the action are computed using the Regge-Teitelboim Hamiltonian approach. They correspond to the mass, which acquires contributions from the scalar field, and the electric charge. We introduce integrability conditions because the scalar field leads to non-integrable terms in the variation of the mass. These conditions are generically solved by introducing boundary conditions that relate the leading and subleading terms of the scalar field fall-off. The Hamiltonian Euclidean action, computed in the grand canonical ensemble, is obtained by demanding the action to have an extremum. Its value is given by a radial boundary term plus an additional polar angle boundary term due to the presence of a magnetic monopole. Remarkably, the magnetic charge can be identified from the variation of the additional polar angle boundary term, confirming that the first law of black hole thermodynamics is a consequence of having a well-defined and finite Hamiltonian action principle, even if the charge does not come from a symmetry of the action. The temperature and electrostatic potential are determined by demanding regularity of the black hole solution, whereas the value of the magnetic potential is determined by the variation of the additional polar angle boundary term. Consequently, the first law of black hole thermodynamics is identically satisfied by construction.
Instability of charged anti-de Sitter black holes
Gwak, Bogeun; Lee, Bum-Hoon; Ro, Daeho
2016-10-01
We have studied the instability of charged anti-de Sitter black holes in four- or higher-dimensions under fragmentation. The unstable black holes under fragmentation can be broken into two black holes. Instability depends not only on the mass and charge of the black hole but also on the ratio between the fragmented black hole and its predecessor. We have found that the near extremal black holes are unstable, and Schwarzschild-AdS black holes are stable. These are qualitatively similar to black holes in four dimensions and higher. The detailed instabilities are numerically investigated.
Black hole solutions in Einstein-charged scalar field theory
Ponglertsakul, Supakchai; Winstanley, Elizabeth
2015-01-01
We investigate possible end-points of the superradiant instability for a charged black hole with a reflecting mirror. By considering a fully coupled system of gravity and a charged scalar field, hairy black hole solutions are obtained. The linear stability of these black hole solutions is studied.
Charged fermions tunneling from accelerating and rotating black holes
Energy Technology Data Exchange (ETDEWEB)
Rehman, Mudassar; Saifullah, K., E-mail: mudassir051@yahoo.com, E-mail: saifullah@qau.edu.pk [Department of Mathematics, Quaid-i-Azam University, Islamabad (Pakistan)
2011-03-01
We study Hawking radiation of charged fermions from accelerating and rotating black holes with electric and magnetic charges. We calculate the tunneling probabilities of incoming and outgoing fermionic particles and find the Hawking temperature of these black holes. We also provide an explicit expression of the classical action for the massive and massless particles in the background of these black holes.
Dando, O
1999-01-01
We examine the field equations of a self-gravitating texture in low-energy superstring gravity, allowing for an arbitrary coupling of the texture field to the dilaton. Both massive and massless dilatons are considered. For the massless dilaton, we find that non-singular spacetimes only exist for certain values of the coupling, dependent on the gravitational strength of the texture. For the massive dilaton, the texture induces a long-range dilaton cloud, but we expect the gravitational behaviour of the defect to be similar to that found in Einstein theory. We compare these results with those found for other global topological defects.
Stability of charged black holes in string theory under charged massive scalar perturbations
Li, Ran
2013-01-01
Similar to the superradiant effect in Reissner-Nordstr\\"{o}m black hole, a charged scalar field can be amplified when impinging on the charged black hole in string theory. According to the black-hole bomb mechanism, the mass term of the incident field can effectively works as the reflecting mirror, which may trigger the instability of black hole. We study the possible instability triggered by superradiant effect and demonstrate that the charged black hole in string theory is stable against the massive charged scalar perturbation. The reason is that there is no trapping potential well in the black hole exterior and there is no bound states in the superradiant regime.
Einstein-Euler-Heisenberg Theory and Charged Black Holes
Ruffini, Remo; Xue, She-Sheng
2013-01-01
Taking into account the Euler-Heisenberg effective Lagrangian of one-loop nonperturbative Quantum Electrodynamics (QED) contributions, we formulate the Einstein-Euler-Heisenberg theory, and study the solutions of non-rotating black holes with electric and magnetic charges in spherical geometry. In the limit of strong and weak electromagnetic fields of black holes, we calculate the black hole horizon radius, area, and total energy up to the leading order of QED corrections, and discuss the black hole irreducible mass, entropy, and maximally extractable energy as well as the Christodoulou-Ruffini mass formula. We find that these black hole quantities receive the QED corrections, in comparison with their counterparts in the Reissner-Nortstr\\"om solution. The QED corrections show the screening effect on black hole electric charges and the paramagnetic effect on black hole magnetic charges. As a result, the black hole horizon area, irreducible mass, and entropy increase, however the black hole total energy and max...
Cardy formula for charged black holes with anisotropic scaling
Bravo-Gaete, Moises; Hassaine, Mokhtar
2015-01-01
We first observe that for Lifshitz black holes whose only charge is the mass, the resulting Smarr relation is a direct consequence of the Lifshitz Cardy formula. From this observation, we propose to extend the Cardy formula to the case of electrically charged Lifshitz black holes satisfying as well a Smarr relation. The expression of our formula depends on the dynamical exponent, the energy and the charge of the ground state which is played by a magnetically charged soliton obtained through a double Wick rotation. The expression also involves a factor multiplying the chemical potentials which varies in function of the electromagnetic theory considered. This factor is precisely the one that appears in the Smarr formula for charged Lifshitz black holes. We test the validity of this Cardy formula in different situations where electrically Lifshitz charged black holes satisfying a Smarr relation are known. We then extend these results to electrically charged black holes with hyperscaling violation. Finally, an ex...
Stationary charged scalar clouds around black holes in string theory
Bernard, Canisius
2016-10-01
It was reported that Kerr-Newman black holes can support linear charged scalar fields in their exterior regions. These stationary massive charged scalar fields can form bound states, which are called stationary scalar clouds. In this paper, we show that Kerr-Sen black holes can also support stationary massive charged scalar clouds by matching the near- and far-region solutions of the radial part of the Klein-Gordon wave equation. We also review stationary scalar clouds within the background of static electrically charged black hole solutions in the low-energy limit of heterotic string field theory, namely, the Gibbons-Maeda-Garfinkle-Horowitz-Strominger black holes.
Stationary Charged Scalar Clouds around Black Holes in String Theory
Bernard, Canisius
2016-01-01
It was reported that Kerr-Newman black holes can support linear charged scalar field in their exterior regions. This stationary massive charged scalar field can form a bound-state and these bound-states are called stationary scalar clouds. In this paper, we study that Kerr-Sen black holes can also support stationary massive charged scalar clouds by matching the near and far region solutions of the radial part of Klein-Gordon wave equation. We also review stationary scalar clouds within the background of static electrically charged black hole solution in the low energy limit of heterotic string field theory namely the GMGHS black holes.
Phantom Energy Accretion by a Stringy Charged Black Hole
Institute of Scientific and Technical Information of China (English)
M.Sharif; G.Abbas
2012-01-01
We investigate the dynamical behavior of phantom energy near a stringy magnetically charged black hole. For this purpose, we derive equations of motion for steady-state spherically symmetric Row of phantom energy onto the stringy magnetically charged black hole. It is found that phantom energy accreting onto a black hole decreases its mass. Further, the location of the critical points of accretion is explored, which yields a mass to charge ratio. This ratio implies that accretion process cannot transform a black hole into an extremal black hole or a naked singularity, hence cosmic censorship hypothesis remains valid here.%We investigate the dynamical behavior of phantom energy near a stringy magnetically charged black hole.For this purpose,we derive equations of motion for steady-state spherically symmetric flow of phantom energy onto the stringy magnetically charged black hole.It is found that phantom energy accreting onto a black hole decreases its mass.Further,the location of the critical points of accretion is explored,which yields a mass to charge ratio.This ratio implies that accretion process cannot transform a black hole into an extremal black hole or a naked singularity,hence cosmic censorship hypothesis remains valid here.
Charged scalar perturbations around Garfinkle–Horowitz–Strominger black holes
Directory of Open Access Journals (Sweden)
Cheng-Yong Zhang
2015-10-01
Full Text Available We examine the stability of the Garfinkle–Horowitz–Strominger (GHS black hole under charged scalar perturbations. Employing the appropriate numerical methods, we show that the GHS black hole is always stable against charged scalar perturbations. This is different from the results obtained in the de Sitter and anti-de Sitter black holes. Furthermore, we argue that in the GHS black hole background there is no amplification of the incident charged scalar wave to cause the superradiance, so that the superradiant instability cannot exist in this spacetime.
Black Holes with Multiple Charges and the Correspondence Principle
Yang, H
1998-01-01
We consider the entropy of near extremal black holes with multiple charges in the context of the recently proposed correspondence principle of Horowitz and Polchinski, including black holes with two, three and four Ramond-Ramond charges. We find that at the matching point the black hole entropy can be accounted for by massless open strings ending on the D-branes for all cases except a black hole with four Ramond-Ramond charges, in which case a possible resolution in terms of brane-antibrane excitations is considered.
Strong field gravitational lensing by a charged Galileon black hole
Zhao, Shan-Shan
2016-01-01
Strong field gravitational lensings are dramatically disparate from those in the weak field by representing relativistic images due to light winds one to infinity loops around a lens before escaping. We study such a lensing caused by a charged Galileon black hole, which is expected to have possibility to evade no-hair theorem. We calculate the angular separations and time delays between different relativistic images of the charged Galileon black hole. All these observables can potentially be used to discriminate a charged Galileon black hole from others. We estimate the magnitudes of the observables for the closest suppermassive black hole Sgr A*. It is found that when the scalar filed in the Galileon is weakly coupled to the gravitational field and it is "low-speed", the charged Galileon black hole can possibly be distinguished from a Reissner-Nordstr\\"om black hole.
Dando, Owen; Gregory, Ruth
1998-07-01
We examine the field equations of a self-gravitating global string in low energy superstring gravity, allowing for an arbitrary coupling of the global string to the dilaton. Massive and massless dilatons are considered. For the massive dilaton the spacetime is similar to the recently discovered non-singular time-dependent Einstein self-gravitating global string, but the massless dilaton generically gives a singular spacetime, even allowing for time dependence. We also demonstrate a time-dependent non-singular string-antistring configuration, in which the string pair causes a compactification of two of the spatial dimensions, albeit on a very large scale.
Dando, O; Dando, Owen; Gregory, Ruth
1998-01-01
We examine the field equations of a self-gravitating global string in low energy superstring gravity, allowing for an arbitrary coupling of the global string to the dilaton. Massive and massless dilatons are considered. For the massive dilaton the spacetime is similar to the recently discovered non-singular time-dependent Einstein self-gravitating global string, but the massless dilaton generically gives a singular spacetime, even allowing for time-dependence. We also demonstrate a time-dependent non-singular string/anti-string configuration, in which the string pair causes a compactification of two of the spatial dimensions, albeit on a very large scale.
Instability of Charged Anti-de Sitter Black Holes
Gwak, Bogeun; Ro, Daeho
2015-01-01
We study the instability of charged anti-de Sitter black holes in four or higher-dimension under fragmentation. The instability of fragmentation breaks the black hole into two black holes. We have found that the region near extremal or massive black holes become unstable under fragmentation. These regions depend not only on the mass and charge of initial black hole but also those of the fragmented one. The instability in higher-dimension is qualitatively similar to that of four-dimension. The detailed instabilities are numerically investigated.
Ohta, Nobuyoshi
2013-01-01
We study charged black hole solutions in Einstein-Maxwell-Gauss-Bonnet theory with the dilaton field which is the low-energy effective theory of the heterotic string. The spacetime is $D$-dimensional and assumed to be static and plane symmetric with the $(D-2)$-dimensional constant curvature space and asymptotically anti-de Sitter. By imposing the boundary conditions of the existence of the regular black hole horizon and proper behavior at infinity where the Breitenlohner-Freedman bound should be satisfied, we construct black hole solutions numerically. We give the relations among the physical quantities of the black holes such as the horizon radius, the mass, the temperature, and so on. The properties of the black hole do not depend on the dimensions qualitatively, which is different from the spherically symmetric and asymptotically flat case. There is non-zero lower limit for the radius of the event horizon below which no solution exists. The temperature of the black hole becomes smaller as the horizon radi...
Holographic Fermions in Anisotropic Einstein-Maxwell-Dilaton-Axion Theory
Directory of Open Access Journals (Sweden)
Li-Qing Fang
2015-01-01
Full Text Available We investigate the properties of the holographic Fermionic system dual to an anisotropic charged black brane bulk in Einstein-Maxwell-Dilaton-Axion gravity theory. We consider the minimal coupling between the Dirac field and the gauge field in the bulk gravity theory and mainly explore the dispersion relation exponents of the Green functions of the dual Fermionic operators in the dual field theory. We find that along both the anisotropic and the isotropic directions the Fermi momentum will be effected by the anisotropy of the bulk theory. However, the anisotropy has influence on the dispersion relation which is almost linear for massless Fermions with charge q=2. The universal properties that the mass and the charge of the Fermi possibly correspond to nonlinear dispersion relation are also investigated.
“Triangular” extremal dilatonic dyons
Directory of Open Access Journals (Sweden)
Dmitri Gal'tsov
2015-04-01
Full Text Available Explicit dyonic solutions in four-dimensional Einstein–Maxwell-dilaton theory are known only for three particular values of the dilaton coupling constant: a=0,1,3. However, numerical evidence was presented on existence of dyons admitting an extremal limit in theories with more general sequence of dilaton couplings a=n(n+1/2 labeled by an integer n. Apart from the lower members n=0,1,2, this family of theories does not have motivation from supergravity/string theory, and analytical origin of the above sequence remained unclear so far. We fill the gap showing that this formula follows from analyticity of the dilaton function at the AdS2×S2 event horizon of the extremal dyonic black hole, with n being the leading dilaton power in the Taylor expansion. We also derive generalization of this rule for asymptotically anti-de Sitter dyonic black holes with spherical, planar and hyperbolic topology of the horizon.
A strongly coupled anisotropic fluid from dilaton driven holography
Jain, Sachin; Kundu, Nilay; Sen, Kallol; Sinha, Aninda; Trivedi, Sandip(Department of Theoretical Physics, Tata Institute of Fundamental Research, Colaba, Mumbai, 400005, India)
2015-01-01
We consider a system consisting of $5$ dimensional gravity with a negative cosmological constant coupled to a massless scalar, the dilaton. We construct a black brane solution which arises when the dilaton satisfies linearly varying boundary conditions in the asymptotically $AdS_5$ region. The geometry of this black brane breaks rotational symmetry while preserving translational invariance and corresponds to an anisotropic phase of the system. Close to extremality, where the anisotropy is big...
Quantum Gravity Effects On Charged Micro Black Holes Thermodynamics
Abbasvandi, N; Radiman, Shahidan; Abdullah, W A T Wan
2016-01-01
The charged black hole thermodynamics is corrected in terms of the quantum gravity effects. Most of the quantum gravity theories support the idea that near the Planck scale, the standard Heisenberg uncertainty principle should be reformulated by the so-called Generalized Uncertainty Principle (GUP) which provides a perturbation framework to perform required modifications of the black hole quantities. In this paper, we consider the effects of the minimal length and maximal momentum as GUP type I and the minimal length, minimal momentum, and maximal momentum as GUP type II on thermodynamics of the charged TeV-scale black holes. We also generalized our study to the universe with the extra dimensions based on the ADD model. In this framework, the effect of the electrical charge on thermodynamics of the black hole and existence of the charged black hole remnants as a potential candidate for the dark matter particles are discussed.
Stringy Sphalerons and Non-Abelian Black Holes
Donets, E E
1993-01-01
Static spherically symmetric asymptotically flat particle-like and black hole solutions are constructed within the SU(2) sector of 4-dimensional heterotic string effective action. They separate topologically distinct Yang-Mills vacua and are qualitatively similar to the Einstein-Yang-Mills spha- lerons and non-abelian black holes discussed recently. New solutions possess quantized values of the dilaton charge.
Null geodesics in a magnetically charged stringy black hole spacetime
Kuniyal, Ravi Shankar; Uniyal, Rashmi; Nandan, Hemwati; Purohit, K. D.
2016-04-01
We study the null geodesics of a four-dimensional magnetic charged black hole spacetime arising in string theory. The behaviour of effective potential in view of the different values of black hole parameters are analysed in the equatorial plane. The possible orbits for null geodesics are also discussed in view of the different values of the impact parameter. We have also calculated the frequency shift of photons in this spacetime. The results are compared to those obtained for the electrically charged stringy black hole spacetime and the Schwarzschild black hole spacetime in general relativity.
Three dimensional dilatonic gravity's rainbow: exact solutions
Hendi, Seyed Hossein; Panahiyan, Shahram
2016-01-01
Deep relations of dark energy scenario and string theory results with dilaton gravity, on one hand, and the connection between quantum gravity with gravity's rainbow, on the other hand, motivate us to consider three dimensional dilatonic black hole solutions in gravity's rainbow. We obtain two classes of the solutions which are polynomial and logarithmic forms. We also calculate conserved and thermodynamic quantities, and examine the first law of thermodynamics for both classes. In addition, we study thermal stability and show that one of the classes is thermally stable while the other one is unstable.
Global monopoles in dilaton gravity
Dando, Owen; Gregory, Ruth
1998-04-01
We analyse the gravitational field of a global monopole within the context of low-energy string gravity, allowing for an arbitrary coupling of the monopole fields to the dilaton. Both massive and massless dilatons are considered. We find that, for a massless dilaton, the spacetime is generically singular, whereas when the dilaton is massive, the monopole generically induces a long-range dilaton cloud. We compare and contrast these results with the literature.
Global Monopoles in Dilaton Gravity
Dando, O; Dando, Owen; Gregory, Ruth
1998-01-01
We analyse the gravitational field of a global monopole within the context of low energy string gravity, allowing for an arbitrary coupling of the monopole fields to the dilaton. Both massive and massless dilatons are considered. We find that, for a massless dilaton, the spacetime is generically singular, whereas when the dilaton is massive, the monopole generically induces a long range dilaton cloud. We compare and contrast these results with the literature.
Entropy bound of horizons for charged and rotating black holes
Directory of Open Access Journals (Sweden)
Wei Xu
2015-06-01
Full Text Available We revisit the entropy product, entropy sum and other thermodynamic relations of charged and rotating black holes. Based on these relations, we derive the entropy (area bound for both event horizon and Cauchy horizon. We establish these results for variant class of 4-dimensional charged and rotating black holes in Einstein(–Maxwell gravity and higher derivative gravity. We also generalize the discussion to black holes with NUT charge. The validity of this formula, which seems to be universal for black holes with two horizons, gives further clue on the crucial role that the thermodynamic relations of multi-horizons play in black hole thermodynamics and understanding the entropy at the microscopic level.
Entropy bound of horizons for charged and rotating black holes
Energy Technology Data Exchange (ETDEWEB)
Xu, Wei, E-mail: xuweifuture@gmail.com [School of Physics, Huazhong University of Science and Technology, Wuhan 430074 (China); Wang, Jia, E-mail: wangjia2010@mail.nankai.edu.cn [School of Physics, Nankai University, Tianjin 300071 (China); Meng, Xin-he, E-mail: xhm@nankai.edu.cn [School of Physics, Nankai University, Tianjin 300071 (China); State Key Laboratory of Institute of Theoretical Physics, Institute of Theoretical Physics, Chinese Academy of Sciences, Beijing 100190 (China)
2015-06-30
We revisit the entropy product, entropy sum and other thermodynamic relations of charged and rotating black holes. Based on these relations, we derive the entropy (area) bound for both event horizon and Cauchy horizon. We establish these results for variant class of 4-dimensional charged and rotating black holes in Einstein(–Maxwell) gravity and higher derivative gravity. We also generalize the discussion to black holes with NUT charge. The validity of this formula, which seems to be universal for black holes with two horizons, gives further clue on the crucial role that the thermodynamic relations of multi-horizons play in black hole thermodynamics and understanding the entropy at the microscopic level.
A rotating charged black hole solution in () gravity
Indian Academy of Sciences (India)
Alexis Larrañaga
2012-05-01
In the context of () theories of gravity, we address the problem of ﬁnding a rotating charged black hole solution in the case of constant curvature. A new metric is obtained by solving the ﬁeld equations and we show that its behaviour is typical of a rotating charged source. In addition, we analyse the thermodynamics of the new black hole. The results ensure that the thermodynamical properties in () gravities are qualitatively similar to those of standard General Relativity.
Quantum loop corrections of charged dS black hole
Naji, J
2016-01-01
In this paper, a charged black hole in de Sitter space considered and logarithmic corrected entropy used to study thermodynamics. Logarithmic corrections of entropy comes from thermal fluctuations which plays role of quantum loop corrections. In that case we are able to study the effect of quantum loop on the black hole thermodynamics and statistics. As black hole is a gravitational object, so it helps to obtain some information about the quantum gravity.
Shadow of a Charged Rotating Non-Commutative Black Hole
Sharif, M
2016-01-01
This paper investigates the shadow of a charged rotating non-commutative black hole. For this purpose, we first formulate the null geodesics and study the effects of non-commutative charge on the photon orbit. We then explore the effect of spin, angle of inclination as well as non-commutative charge on the silhouette of the shadow. It is found that shape of the shadow deviates from the circle with the decrease in the non-commutative charge. We also discuss observable quantities to study the deformation and distortion in the shadow cast by the black hole which decreases for small values of non-commutative charge. Finally, we study the shadows in the presence of plasma. We conclude that the non-commutativity has a great impact on the black hole shadow.
The Mixed Phase of Charged AdS Black Holes
Directory of Open Access Journals (Sweden)
Piyabut Burikham
2016-01-01
Full Text Available We study the mixed phase of charged AdS black hole and radiation when the total energy is fixed below the threshold to produce a stable charged black hole branch. The coexistence conditions for the charged AdS black hole and radiation are derived for the generic case when radiation particles carry charge. The phase diagram of the mixed phase is demonstrated for both fixed potential and charge ensemble. In the dual gauge picture, they correspond to the mixed phase of quark-gluon plasma (QGP and hadron gas in the fixed chemical potential and density ensemble, respectively. In the nuclei and heavy-ion collisions at intermediate energies, the mixed phase of exotic QGP and hadron gas could be produced. The mixed phase will condense and evaporate into the hadron gas as the fireball expands.
Shadow of a charged rotating non-commutative black hole
Energy Technology Data Exchange (ETDEWEB)
Sharif, M. [University of the Punjab, Department of Mathematics, Lahore (Pakistan); Pakistan Academy of Sciences, Islamabad (Pakistan); Iftikhar, Sehrish [University of the Punjab, Department of Mathematics, Lahore (Pakistan)
2016-11-15
This paper investigates the shadow of a charged rotating non-commutative black hole. For this purpose, we first formulate the null geodesics and study the effects of a non-commutative charge on the photon orbit. We then explore the effect of spin, angle of inclination as well as non-commutative charge on the silhouette of the shadow. It is found that shape of the shadow deviates from the circle with the decrease in the non-commutative charge. We also discuss observable quantities to study the deformation and distortion in the shadow cast by the black hole which decreases for small values of a non-commutative charge. Finally, we study the shadows in the presence of plasma. We conclude that the non-commutativity has a great impact on the black hole shadow. (orig.)
Internal Structure of Charged AdS Black Holes
Bhattacharjee, Srijit; Virmani, Amitabh
2016-01-01
When an electrically charged black hole is perturbed its inner horizon becomes a singularity, often referred to as the Poisson-Israel mass inflation singularity. Ori constructed a model of this phenomenon for asymptotically flat black holes, in which the metric can be determined explicitly in the mass inflation region. In this paper we implement the Ori model for charged AdS black holes. We find that the mass function inflates faster than the flat space case as the inner horizon is approached. Nevertheless, the mass inflation singularity is still a weak singularity: although spacetime curvature becomes infinite, tidal distortions remain finite on physical objects attempting to cross it.
Thermodynamics and Geometrothermodynamics of Charged black holes in Massive Gravity
Suresh, Jishnu; Prabhakar, Geethu; Kuriakose, V C
2016-01-01
The objective of this paper is to study the thermodynamics and thermodynamic geometry of charged de-Sitter and charged anti de-Sitter black hole solutions in massive gravity. In this study, the presence of a negative cosmological constant is identified as a thermodynamic variable, the pressure. By incorporating this idea, we study the effect of curvature parameter as well as the mass of graviton in the thermodynamics of the black hole system. We further extend our studies to different topology of the space time and its effects on phase transition and thermodynamics. In addition, the phase transition structure of the black hole and its interactions are reproduced using geometrothermodynamics.
Institute of Scientific and Technical Information of China (English)
张丽春; 武月琴; 赵仁
2002-01-01
该文利用Brick-wall方法,计算轴对称Einstein-Maxwell-Dilaton-Axion黑洞背景下标量场的自由能和熵.结果表明,当黑洞具有内外视界时,所得熵不仅与外视界面积有关,而且也是内视界面积的函数.当内视界面积趋于零时,可回到已知结论.并且表明,用内外视界位置参量表达的熵.在黑洞辐射温度趋于绝对零度时,黑洞的熵也趋于零,它满足能斯特定理,可视为黑洞的普朗克绝对熵.
Correction value to charged Bekenstein-Hawking black hole entropy
Institute of Scientific and Technical Information of China (English)
2008-01-01
Recently,based on the study of black hole Hawking radiation with the tunnel effect method,we found that the radiation spectrum of the black hole is not a strict pure thermal spectrum. It is a very interesting problem to determine how the departure of the black hole radiation spectrum from the pure thermal spectrum affects entropy. We calculate the partition function by the energy spectrum obtained using tunnel effect. Using the relation between the partition function and entropy,we derive the correction value to Bekenstein-Hawking entropy of the charged black hole. Fur-thermore,we obtain the conditions that various thermodynamic quantities must satisfy,when phase transition of the charged black hole occurs.
Dynamics in the Charged Time Conformal Schwarzschild Black Hole
Jawad, Abdul; Shahzad, M Umair; Abbas, G
2016-01-01
In this work, we present the new technique for discussing the dynamical motion of neutral as well as charged particles in the absence/presence of magnetic field around the time conformal Schwarzschild black hole. Initially, we find the numerical solutions of geodesics of Schwarzschild black hole and the time conformal Schwarzschild black hole. We observe that the Schwarzschild spacetime admits the time conformal factor $e^{\\epsilon f(t)}$, where $f(t)$ is an arbitrary function and $\\epsilon$ is very small which causes the perturbation in the spacetimes. This technique also re-scale the energy content of spacetime. We also investigate the thermal stability, horizons and energy conditions corresponding time conformal Schwarzschild spacetime. Also, we examine the dynamics of neutral and charged particle around time conformal Schwarzschild black hole. We investigate the circumstances under which the particle can escape from vicinity of black hole after collision with another particle. We analyze the effective pot...
Thermodynamics of charged Lovelock: AdS black holes
Energy Technology Data Exchange (ETDEWEB)
Prasobh, C.B.; Suresh, Jishnu; Kuriakose, V.C. [Cochin University of Science and Technology, Department of Physics, Cochin (India)
2016-04-15
We investigate the thermodynamic behavior of maximally symmetric charged, asymptotically AdS black hole solutions of Lovelock gravity. We explore the thermodynamic stability of such solutions by the ordinary method of calculating the specific heat of the black holes and investigating its divergences which signal second-order phase transitions between black hole states. We then utilize the methods of thermodynamic geometry of black hole spacetimes in order to explain the origin of these points of divergence. We calculate the curvature scalar corresponding to a Legendre-invariant thermodynamic metric of these spacetimes and find that the divergences in the black hole specific heat correspond to singularities in the thermodynamic phase space. We also calculate the area spectrum for large black holes in the model by applying the Bohr-Sommerfeld quantization to the adiabatic invariant calculated for the spacetime. (orig.)
Thermodynamics of charged Lovelock: AdS black holes
Prasobh, C. B.; Suresh, Jishnu; Kuriakose, V. C.
2016-04-01
We investigate the thermodynamic behavior of maximally symmetric charged, asymptotically AdS black hole solutions of Lovelock gravity. We explore the thermodynamic stability of such solutions by the ordinary method of calculating the specific heat of the black holes and investigating its divergences which signal second-order phase transitions between black hole states. We then utilize the methods of thermodynamic geometry of black hole spacetimes in order to explain the origin of these points of divergence. We calculate the curvature scalar corresponding to a Legendre-invariant thermodynamic metric of these spacetimes and find that the divergences in the black hole specific heat correspond to singularities in the thermodynamic phase space. We also calculate the area spectrum for large black holes in the model by applying the Bohr-Sommerfeld quantization to the adiabatic invariant calculated for the spacetime.
Rotating black holes with non-Abelian hair
Kleihaus, Burkhard; Navarro-Lerida, Francisco
2016-01-01
We here review asymptotically flat rotating black holes in the presence of non-Abelian gauge fields. Like their static counterparts these black holes are no longer uniquely determined by their global charges. In the case of pure SU(2) Yang-Mills fields, the rotation generically induces an electric charge, while the black holes do not carry a magnetic charge. When a Higgs field is coupled, rotating black holes with monopole hair arise in the case of a Higgs triplet, while in the presence of a complex Higgs doublet the black holes carry sphaleron hair. The inclusion of a dilaton allows for Smarr type mass formulae.
Superrotation Charge and Supertranslation Hair on Black Holes
Hawking, Stephen W; Strominger, Andrew
2016-01-01
It is shown that black hole spacetimes in classical Einstein gravity are characterized by, in addition to their ADM mass M , momentum P ~ , angular momentum J ~ and boost charge K, an infinite head of supertranslation hair. The distinct black holes are distinguished by classical superrotation charges measured at infinity. Solutions with supertranslation hair are diffeomorphic to the Schwarzschild spacetime, but the diffeomorphisms are part of the BMS subgroup and act nontrivially on the physical phase space. It is shown that a black hole can be supertranslated by throwing in an asymmetric shock wave. A leading-order Bondi-gauge expression is derived for the linearized horizon supertranslation charge and shown to generate, via the Dirac bracket, supertranslations on the linearized phase space of gravitational excitations of the horizon. The considerations of this paper are largely classical augmented by comments on their implications for the quantum theory.
Entropy Corrections for a Charged Black Hole of String Theory*
Institute of Scientific and Technical Information of China (English)
Alexis Larra(n)aga
2011-01-01
We study the entropy of the Gibbons-Macda-Garfinkle-Horowitz-Strominger (GMGHS) charged black hole, originated from the effective action that emerges in the low-energy of string theory, beyond semiclassical approximations. Applying the properties of exact differentials for three variables to the first law thermodynamics ve derive the quantum corrections to the entropy of the black hole. The leading (logarithmic) and non leading corrections to the area law are obtained.
D0-brane description of the charged black hole
Kato, Y; Sugamoto, A; Kato, Yuriko; Nojiri, Shin'ichi; Sugamoto, Akio
1998-01-01
The charged black hole is considered from the viewpoint of D0-brane in the Matrix theory. It can be obtained from the Kaluza-Klein mechanism by boosting the Schwarzschild black hole in a circle, which is the compactified one dimensional space. Especially, how the extremal limit is realized by the Boltzmann gas of D0-brane, has been shown. In the course of our discussion, the Virial theorem for the statistical average plays an important role.
Quasinormal modes of semiclassical electrically charged black holes
Energy Technology Data Exchange (ETDEWEB)
Fernandez Piedra, Owen Pavel [Departamento de Fisica y Quimica, Facultad de Mecanica, Universidad de Cienfuegos, Carretera a Rodas, km 4, Cuatro Caminos, Cienfuegos (Cuba); De Oliveira, Jeferson, E-mail: opavel@ucf.edu.cu, E-mail: jeferson@fma.if.usp.br [Instituto de Fisica, Universidade de Sao Paulo, CP 66318, 05315-970, Sao Paulo (Brazil)
2011-04-21
We report the results concerning the influence of vacuum polarization due to quantum massive vector, scalar and spinor fields on the scalar sector of quasinormal modes in spherically symmetric charged black holes. The vacuum polarization from quantized fields produces a shift in the values of the quasinormal frequencies, and correspondingly the semiclassical system becomes a better oscillator with respect to the classical Reissner-Nordstroem black hole.
Electromagnetic Luminosity of the Coalescence of Charged Black Hole Binaries
Liebling, Steven L
2016-01-01
The observation of a possible electromagnetic counterpart by the Fermi GBM group to the aLIGO detection of the merger of a black hole binary has spawned a number of ideas about its source. Furthermore, observations of fast radio bursts (FRBs) have similarly resulted in a range of new models that might endow black hole binaries with electromagnetic signatures. In this context, even the unlikely idea that astrophysical black holes may have significant charge is worth exploring, and here we present results from the simulation of weakly charged black holes as they orbit and merge. Our simulations suggest that a black hole binary with mass comparable to that observed in GW150914 could produce the level of electromagnetic luminosity observed by Fermi GBM ($10^{49}$ ergs/s) with a non-dimensional charge of $q \\equiv Q/M = 10^{-4}$ assuming good radiative efficiency. However even a charge such as this is difficult to imagine avoiding neutralization long enough for the binary to produce its electromagnetic counterpart...
Power Law of Shear Viscosity in Einstein-Maxwell-Dilaton-Axion model
Ling, Yi; Zhou, Zhenhua
2016-01-01
We construct charged black hole solutions with hyperscaling violation in the infrared(IR) region in Einstein-Maxwell-Dilaton-Axion theory and investigate the temperature behavior of the ratio of holographic shear viscosity to the entropy density. When translational symmetry breaking is relevant in the IR, the power law of the ratio is testified numerically at low temperature $T$, namely, $\\eta/s\\sim T^\\kappa$, where the values of exponent $\\kappa$ coincide with the analytical results. We also find that the exponent $\\kappa$ is not affected by irrelevant current, but is reduced by the relevant current.
Vacum Black Hole Mass Formula Is a Vanishing Noether Charge
Institute of Scientific and Technical Information of China (English)
WUXiao－Ning; HUANGChao－Guang; 等
2002-01-01
The Noether current and its variation relation with respect to diffeomorphism invariance of gravitational theories have been derived from the horizontal variation and vertical-horizontal bi-variation of the Lagrangian,respectively.For Einstein's GR in the stationary,axisymmetric black holes,the mass formula in vacuum can be derived from this Noether current although it definitely vanishes.This indicates that the mass formula of black holes is a vanishing Noether charge in this case.The first law of black hole thermodynamics can also be derived from the variation relation of this vanishing Noether current.
Black hole entropy and Lorentz-diffeomorphism Noether charge
Jacobson, Ted; Mohd, Arif
2015-01-01
We show that, in the first or second order orthonormal frame formalism, black hole entropy is the horizon Noether charge for a combination of diffeomorphism and local Lorentz symmetry involving the Lie derivative of the frame. The Noether charge for diffeomorphisms alone is unsuitable, since a regular frame cannot be invariant under the flow of the Killing field at the bifurcation surface. We apply this formalism to Lagrangians polynomial in wedge products of the frame field 1-form and curvat...
Geometric aspects of charged black holes in Palatini theories
Olmo, Gonzalo J; Sanchez-Puente, A
2015-01-01
Charged black holes in gravity theories in the Palatini formalism present a number of unique properties. Their innermost structure is topologically nontrivial, representing a wormhole supported by a sourceless electric flux. For certain values of their effective mass and charge curvature divergences may be absent, and their event horizon may also disappear yielding a remnant. We give an overview of the mathematical derivation of these solutions and discuss their geodesic structure and other geometric properties.
Explosion and final state of the charged black hole bomb
Sanchis-Gual, Nicolas; Montero, Pedro J; Font, José A; Herdeiro, Carlos
2015-01-01
A Reissner-Nordstr\\"om black hole (BH) is superradiantly unstable against spherical perturbations of a charged scalar field, enclosed in a cavity, with frequency lower than a critical value. We use numerical relativity techniques to follow the development of this unstable system -- dubbed charged BH bomb -- into the non-linear regime, solving the full Einstein--Maxwell--Klein-Gordon equations, in spherical symmetry. We show that: $i)$ the process stops before all the charge is extracted from the BH; $ii)$ the system settles down into a hairy BH: a charged horizon in equilibrium with a scalar field condensate, whose phase is oscillating at the (final) critical frequency. For low scalar field charge, $q$, the final state is approached smoothly and monotonically. For large $q$, however, the energy extraction overshoots and an explosive phenomenon, akin to a $bosenova$, pushes some energy back into the BH. The charge extraction, by contrast, does not reverse.
Quasinormal modes of maximally charged black holes
Onozawa, H; Okamura, T; Ishihara, H; Onozawa, Hisashi; Mishima, Takashi; Okamura, Takashi; Ishihara, Hideki
1996-01-01
A new algorithm for computing the accurate values of quasinormal frequencies of extremal Reissner-Nordstr\\"{o}m black holes is presented. The numerically computed values are consistent with the values earlier obtained by Leaver and those obtained through the WKB method. Our results are more precise than other results known to date. We also find a curious fact that the resonant frequencies of gravitational waves with multi-pole index l coincide with those of electromagnetic waves with multi-pole index l-1 in the extremal limit.
Thermodynamics of charged black holes with a nonlinear electrodynamics source
Gonzalez, Hernan A; Martinez, Cristian
2009-01-01
We study the thermodynamical properties of electrically charged black hole solutions of a nonlinear electrodynamics theory defined by a power p of the Maxwell invariant, which is coupled to Einstein gravity in four and higher spacetime dimensions. Depending on the range of the parameter p, these solutions present different asymptotic behaviors. We compute the Euclidean action with the appropriate boundary term in the grand canonical ensemble. The thermodynamical quantities are identified and in particular, the mass and the charge are shown to be finite for all classes of solutions. Interestingly, a generalized Smarr formula is derived and it is shown that this latter encodes perfectly the different asymptotic behaviors of the black hole solutions. The local stability is analyzed by computing the heat capacity and the electrical permittivity and we find that a set of small black holes are locally stable. In contrast to the standard Reissner-Nordstrom solution, there is a first-order phase transition between a ...
Scalar clouds in charged stringy black hole-mirror system
Li, Ran; Zhao, Junkun; Wu, Xinghua; Zhang, Yanming
2015-04-01
It was reported that massive scalar fields can form bound states around Kerr black holes (Herdeiro and Radu, Phys. Rev. Lett. 112:221101, 2014). These bound states are called scalar clouds; they have a real frequency , where is the azimuthal index and is the horizon angular velocity of Kerr black hole. In this paper, we study scalar clouds in a spherically symmetric background, i.e. charged stringy black holes, with the mirror-like boundary condition. These bound states satisfy the superradiant critical frequency condition for a charged scalar field, where is the charge of the scalar field, and is the horizon's electrostatic potential. We show that, for the specific set of black hole and scalar field parameters, the clouds are only possible for specific mirror locations . It is shown that analytical results of the mirror location for the clouds perfectly coincide with numerical results in the regime. We also show that the scalar clouds are also possible when the mirror locations are close to the horizon. Finally, we provide an analytical calculation of the specific mirror locations for the scalar clouds in the regime.
Scalar clouds in charged stringy black hole-mirror system
Li, Ran; Wu, Xinghua; Zhang, Yanming
2015-01-01
It is reported that massive scalar fields can form bound states around Kerr black holes [C. Herdeiro, and E. Radu, Phys. Rev. Lett. 112, 221101 (2014)]. These bound states are called scalar clouds, which have a real frequency $\\omega=m\\Omega_H$, where $m$ is the azimuthal index and $\\Omega_H$ is the horizon angular velocity of Kerr black hole. In this paper, we study scalar clouds in a spherically symmetric background, i.e. charged stringy black holes, with the mirror-like boundary condition. These bound states satisfy the superradiant critical frequency condition $\\omega=q\\Phi_H$ for the charged scalar field, where $q$ is the charge of scalar field, and $\\Phi_H$ is the horizon electrostatic potential. We show that, for the specific set of black hole and scalar field parameters, the clouds are only possible for the specific mirror locations $r_m$. It is shown that the analytical results of mirror location $r_m$ for the clouds are perfectly coincide with the numerical results. In addition, we show that the sca...
Scalar clouds in charged stringy black hole-mirror system
Energy Technology Data Exchange (ETDEWEB)
Li, Ran; Zhao, Junkun; Wu, Xinghua; Zhang, Yanming [Henan Normal University, Department of Physics, Xinxiang (China)
2015-04-15
It was reported that massive scalar fields can form bound states around Kerr black holes (Herdeiro and Radu, Phys. Rev. Lett. 112:221101, 2014). These bound states are called scalar clouds; they have a real frequency ω = mΩ{sub H}, where m is the azimuthal index and Ω{sub H} is the horizon angular velocity of Kerr black hole. In this paper, we study scalar clouds in a spherically symmetric background, i.e. charged stringy black holes, with the mirror-like boundary condition. These bound states satisfy the superradiant critical frequency condition ω = qΦ{sub H} for a charged scalar field, where q is the charge of the scalar field, and Φ{sub H} is the horizon's electrostatic potential. We show that, for the specific set of black hole and scalar field parameters, the clouds are only possible for specific mirror locations r{sub m}. It is shown that analytical results of the mirror location r{sub m} for the clouds perfectly coincide with numerical results in the qQ << 1 regime. We also show that the scalar clouds are also possible when the mirror locations are close to the horizon. Finally, we provide an analytical calculation of the specific mirror locations rm for the scalar clouds in the qQ >> 1 regime. (orig.)
Thermodynamics of charged black holes with a nonlinear electrodynamics source
González, Hernán A.; Hassaïne, Mokhtar; Martínez, Cristián
2009-11-01
We study the thermodynamical properties of electrically charged black hole solutions of a nonlinear electrodynamics theory defined by a power p of the Maxwell invariant, which is coupled to Einstein gravity in four and higher spacetime dimensions. Depending on the range of the parameter p, these solutions present different asymptotic behaviors. We compute the Euclidean action with the appropriate boundary term in the grand canonical ensemble. The thermodynamical quantities are identified and, in particular, the mass and the charge are shown to be finite for all classes of solutions. Interestingly, a generalized Smarr formula is derived and it is shown that this latter encodes perfectly the different asymptotic behaviors of the black hole solutions. The local stability is analyzed by computing the heat capacity and the electrical permittivity and we find that a set of small black holes is locally stable. In contrast to the standard Reissner-Nordström solution, there is a first-order phase transition between a class of these nonlinear charged black holes and the Minkowski spacetime.
Black hole free energy during charged collapse: a numerical study
Beauchesne, Hugues
2012-01-01
We perform a numerical investigation of the thermodynamics during the collapse of a charged (complex) scalar field to a Reissner-Nordstr\\"om (RN) black hole in isotropic coordinates. Numerical work on gravitational collapse in isotropic coordinates has recently shown that the negative of the total Lagrangian approaches the Helmholtz free energy F= E-TS of a Schwarzschild black hole at late times of the collapse (where E is the black hole mass, T the temperature and S the entropy). The relevant thermodynamic potential for the RN black hole is the Gibbs free energy G=E-TS-$\\Phi_H$ Q where Q is the charge and $\\Phi_H$ the electrostatic potential at the outer horizon. In charged collapse, there is a large outgoing matter wave which prevents the exterior from settling quickly to a static state. However, the interior region is not affected significantly by the wave. We find numerically that the interior contribution to the Gibbs free energy is entirely gravitational and accumulates in a thin shell just inside the h...
On the universality of thermodynamics and $\\eta/s$ ratio for the charged Lovelock black branes
Cadoni, Mariano; Frassino, Antonia; Tuveri, Matteo
2016-01-01
We investigate general features of charged Lovelock black branes by giving a detailed description of geometrical, thermodynamic and holographic properties of charged Gauss-Bonnet (GB) black branes in five dimensions. We show that when expressed in terms of effective physical parameters, the thermodynamic behaviour of charged GB black branes is completely indistinguishable from that of charged Einstein black branes. Moreover, the extremal, near-horizon limit of the two classes of branes is exa...
The causal structure of dynamical charged black holes
Energy Technology Data Exchange (ETDEWEB)
Hong, Sungwook E; Hwang, Dong-il; Stewart, Ewan D; Yeom, Dong-han, E-mail: eostm@muon.kaist.ac.k, E-mail: enotsae@gmail.co, E-mail: innocent@muon.kaist.ac.k [Department of Physics, KAIST, Daejeon 305-701 (Korea, Republic of)
2010-02-21
We study the causal structure of dynamical charged black holes, with a sufficient number of massless fields, using numerical simulations. Neglecting Hawking radiation, the inner horizon is a null Cauchy horizon and a curvature singularity due to mass inflation. When we include Hawking radiation, the inner horizon becomes space-like and is separated from the Cauchy horizon, which is parallel to the out-going null direction. Since a charged black hole must eventually transit to a neutral black hole, we studied the neutralization of the black hole and observed that the inner horizon evolves into a space-like singularity, generating a Cauchy horizon which is parallel to the in-going null direction. Since the mass function is finite around the inner horizon, the inner horizon is regular and penetrable in a general relativistic sense. However, since the curvature functions become trans-Planckian, we cannot say more about the region beyond the inner horizon, and it is natural to say that there is a 'physical' space-like singularity. However, if we assume an exponentially large number of massless scalar fields, our results can be extended beyond the inner horizon. In this case, strong cosmic censorship and black hole complementarity can be violated.
Einstein-charged scalar field theory: black hole solutions and their stability
Ponglertsakul, Supakchai; Winstanley, Elizabeth
2015-01-01
A complex scalar field on a charged black hole in a cavity is known to experience a superradiant instability. We investigate possible final states of this instability. We find hairy black hole solutions of a fully coupled system of Einstein gravity and a charged scalar field. The black holes are surrounded by a reflecting mirror. We also investigate the stability of these black holes.
Accretion Onto a Charged Higher-Dimensional Black Hole
Sharif, M
2016-01-01
This paper deals with the steady-state polytropic fluid accretion onto a higher-dimensional Reissner-Nordstr$\\ddot{o}$m black hole. We formulate the generalized mass flux conservation equation, energy flux conservation and relativistic Bernoulli equation to discuss the accretion process. The critical accretion is investigated by finding critical radius, critical sound velocity and critical flow velocity. We also explore gas compression and temperature profiles to analyze the asymptotic behavior. It is found that the results for Schwarzschild black hole are recovered when $q=0$ in four dimensions. We conclude that accretion process in higher dimensions becomes slower in the presence of charge.
Quasinormal Modes of Charged Black Holes Localized in the Randall-Sundrum Brane World
Soleimani, M J; Radiman, Shahidan; Abdullah, W A T Wan
2016-01-01
We study the quasinormal modes of the massless scalar field of charged black holes embedded in the Randal-Sundrum brane world using the third order WKB approximation. We consider the effects of the electromagnetic and tidal charges on quasinormal frequencies spectrum for charged black hole black holes as well as the effect of the thickness of the bulk.
Magnetic monopole solutions with a massive dilaton
Forgács, Péter; Forgacs, Peter; Gyurusi, Jozsef
1998-01-01
Static, spherically symmetric monopole solutions of a spontaneously broken SU(2) gauge theory coupled to a massive dilaton field are studied in detail in function of the dilaton coupling strength and of the dilaton mass.
The Dilaton and Modified Gravity
Brax, Philippe; Davis, Anne-Christine; Shaw, Douglas J
2010-01-01
We consider the dilaton in the strong string coupling limit and elaborate on the original idea of Damour and Polyakov whereby the dilaton coupling to matter has a minimum with a vanishing value at finite field-value. Combining this type of coupling with an exponential potential, the effective potential of the dilaton becomes matter density dependent. We study the background cosmology, showing that the dilaton can play the role of dark energy. We also analyse the constraints imposed by the absence of violation of the equivalence principle. Imposing these constraints and assuming that the dilaton plays the role of dark energy, we consider the consequences of the dilaton on large scale structures and in particular the behaviour of the slip functions and the growth index at low redshift.
Nontopological magnetic monopoles and new magnetically charged black holes
Lee, K; Kimyeong Lee; Erick J Weinberg
1994-01-01
The existence of nonsingular classical magnetic monopole solutions is usually understood in terms of topologically nontrivial Higgs field configurations. We show that finite energy magnetic monopole solutions also exist within a class of purely Abelian gauge theories containing charged vector mesons, even though the possibility of nontrivial topology does not even arise. provided that certain relationships among the parameters of the theory are satisfied. These solutions are singular if these relationships do not hold, but even then become meaningful once the theory is coupled to gravity, for they then give rise to an interesting new class of magnetically charged black holes with hair.
Nontopological magnetic monopoles and new magnetically charged black holes
Lee, Kimyeong; Weinberg, Erick J.
1994-08-01
The existence of nonsingular classical magnetic monopole solutions is usually understood in terms of topologically nontrivial Higgs field configurations. We show that finite energy magnetic monopole solutions also exist within a class of purely Abelian gauge theories containing charged vector mesons, even though the possibility of nontrivial topology does not even arise provided that certain relationships among the parameters of the theory are satisfied. These solutions are singular if these relationships do not hold, but even then become meaningful once the theory is coupled to gravity, for they then give rise to an interesting new class of magnetically charged black holes with hair.
Black hole entropy and Lorentz-diffeomorphism Noether charge
Jacobson, Ted
2015-01-01
We show that, in the first or second order orthonormal frame formalism, black hole entropy is the horizon Noether charge for a combination of diffeomorphism and local Lorentz symmetry involving the Lie derivative of the frame. The Noether charge for diffeomorphisms alone is unsuitable, since a regular frame cannot be invariant under the flow of the Killing field at the bifurcation surface. We apply this formalism to Lagrangians polynomial in wedge products of the frame field 1-form and curvature 2-form, including general relativity, Lovelock gravity, and "topological" terms in four dimensions.
Charged topological black hole with a conformally coupled scalar field
Martínez, C; Martinez, Cristian; Staforelli, Juan Pablo
2006-01-01
An exact four-dimensional electrically charged topological black hole solution with a conformal coupled self-interacting scalar field is shown. We consider a negative cosmological constant and a quartic self-interaction. According to the mass different causal structures appear, including an extremal black hole. In all cases, the asymptotic region is locally an anti-de Sitter spacetime and a curvature singularity at the origin is present. The scalar field is regular on and outside the event horizon, which is a surface of negative constant curvature. We study the thermodynamical properties for the non-extremal black hole in the grand canonical ensemble. The configurations are thermodynamically stable and do not present phase transitions. The entropy value differs from that which the area law dictates. The non-minimal coupling is responsible for that difference and it can be seen as a modification of the Newton's constant.
Entropy of N-Dimensional Spherically Symmetric Charged Black Hole
Institute of Scientific and Technical Information of China (English)
ZHAO Ren; WU Yue-Qin; ZHANG Li-Chun
2003-01-01
By using the method of quantum statistics, we derive directly the partition functions of bosonic andfermionic fields in the N-dimensional spherically symmetric charged black hole space-time. The statistical entropy ofblack hole is obtained by an improved brick-wall method. When we choose proper parameters in our results, we canobtain that the entropy of black hole is proportional to the area of horizon. In our result, there do not exist neglectedterm and divergent logarithmic term given in the original brick-wall method. We avoid the difficulty in solving the waveequation of scalar and Dirac fields. We offer a simple and direct way of studying entropy of the higher-dimensional black hole.
Bai, Yang; Carena, Marcela; Lykken, Joseph
2009-12-31
A dilaton could be the dominant messenger between standard model fields and dark matter. The measured dark matter relic abundance relates the dark matter mass and spin to the conformal breaking scale. The dark matter-nucleon spin-independent cross section is predicted in terms of the dilaton mass. We compute the current constraints on the dilaton from LEP and Tevatron experiments, and the gamma-ray signal from dark matter annihilation to dilatons that could be observed by Fermi Large Area Telescope.
Dilatons in Dense Baryonic Matter
Lee, Hyun Kyu
2013-01-01
We discuss the role of dilaton, which is supposed to be representing a special feature of scale symmetry of QCD, trace anomaly, in dense baryonic matter. The idea that the scale symmetry breaking of QCD is responsible for the spontaneous breaking of chiral symmetry is presented along the similar spirit of Freund-Nambu model. The incorporation of dilaton field in the hidden local symmetric parity doublet model is briefly sketched with the possible role of dilaton at high density baryonic matter, the emergence of linear sigma model in dilaton limit.
Strong Gravitational Lensing by the Large R-Charged Non-Extremal Black Hole
Naji, J
2016-01-01
In this paper, gravitational lensing scenario due to the R-charged black hole of five dimensional supergravity investigated. We study the effective potential of traveling photons near the R-charged black hole and find some stable orbits for the photons. We also find that the effect of the black hole charges is increasing of the effective potential. We have shown that photons do not cross the horizon of the very large R-charged black hole. By using the numerical study we find that the black hole charges and non-extremality parameter decrease value of the deflection angle.
Rotating Charged Hairy Black Hole in (2+1) Dimensions and Particle Acceleration
Sadeghi, J.; Pourhassan, B.; Farahani, H.
2014-09-01
In this paper, we construct rotating charged hairy black hole in (2+1) dimensions for infinitesimal black hole charge and rotation parameters. Then we consider this black hole as particle accelerator and calculate the center-of-mass energy of two colliding test particles near the rotating charged hairy black hole in (2+1) dimensions. As we expected, the center-of-mass energy has infinite value.
Rotating charged hairy black hole in (2+1) dimensions and particle acceleration
Sadeghi, J; Farahani, H
2013-01-01
In this paper we construct rotating charged hairy black hole in (2+1) dimensions for infinitesimal black hole charge and rotation parameters. Then we consider this black hole as particle accelerator and calculate the center-of-mass energy of two colliding test particles near the rotating charged hairy black hole in (2+1) dimensions. As we expected, the center-of-mass energy has infinite value.
Quadrupole Moments of Rapidly Rotating Compact Objects in Dilatonic Einstein-Gauss-Bonnet Theory
Kleihaus, Burkhard; Mojica, Sindy
2014-01-01
We consider rapidly rotating black holes and neutron stars in dilatonic Einstein-Gauss-Bonnet (EGBd) theory and determine their quadrupole moments, which receive a contribution from the dilaton. The quadrupole moment of EGBd black holes can be considerably larger than the Kerr value. For neutron stars, the universality property of the $\\hat I$-$\\hat Q$ relation between the scaled moment of inertia and the scaled quadrupole moment appears to extend to EGBd theory.
Radiation and the classical double copy for color charges
Goldberger, Walter D
2016-01-01
We construct perturbative classical solutions of the Yang-Mills equations coupled to dynamical point particles carrying color charge. By applying a set of color to kinematics replacement rules first introduced by Bern, Carrasco and Johansson (BCJ), these are shown to generate solutions of d-dimensional dilaton gravity, which we also explicitly construct. Agreement between the gravity result and the gauge theory double copy implies a correspondence between non-Abelian particles and gravitating sources with dilaton charge. When the color sources are highly relativistic, dilaton exchange decouples, and the solutions we obtain match those of pure gravity. We comment on possible implications of our findings to the calculation of gravitational waveforms in astrophysical black hole collisions, directly from computationally simpler gluon radiation in Yang-Mills theory.
Black hole entropy from conformal symmetry on the horizon
Carlip, Steven
2017-01-01
The idea that black hole entropy might be governed by a conformal symmetry is an old one, but until now most efforts have focused on either asymptotic symmetries or symmetries on a ``stretched horizon. For two-dimensional dilaton gravity, I show the existence of a well-behaved conformal symmetry that is on the horizon, with a central charge that correctly determines the black hole entropy. Supported by Department of Energy grant DE-FG02-91ER40674.
Manjarin, J J
2001-01-01
In this letter we study the dilatonic corrections to the static gauge potential between heavy sources. These corrections come from the solutions to the the low est order beta equations. In the energetically favoured branch, the potential obtained is characterised by having a linear confining term, an $L$ independent term and another 1/L piece. This is indicative of a L\\"uscher-type behaviour in the strong-coupling regime of the dual gauge theory. On the other hand, we also explore the singularity as a point where the theory becomes free.
No hair theorem in quasi-dilaton massive gravity
Energy Technology Data Exchange (ETDEWEB)
Wu, De-Jun, E-mail: wudejun10@mails.ucas.ac.cn [School of Physics, University of Chinese Academy of Sciences, Beijing 100049 (China); Zhou, Shuang-Yong, E-mail: sxz353@case.edu [Department of Physics, Case Western Reserve University, 10900 Euclid Ave, Cleveland, OH 44106 (United States)
2016-06-10
We investigate the static, spherically symmetric black hole solutions in the quasi-dilaton model and its generalizations, which are scalar extended dRGT massive gravity with a shift symmetry. We show that, unlike generic scalar extended massive gravity models, these theories do not admit static, spherically symmetric black hole solutions until the theory parameters in the dRGT potential are fine-tuned. When fine-tuned, the geometry of the static, spherically symmetric black hole is necessarily that of general relativity and the quasi-dilaton field is constant across the spacetime. The fine-tuning and the no hair theorem apply to black holes with flat, anti-de Sitter or de Sitter asymptotics.
No hair theorem in quasi-dilaton massive gravity
Wu, De-Jun
2016-01-01
We investigate the static, spherically symmetric black hole solutions in the quasi-dilaton model and its generalizations, which are scalar extended dRGT massive gravity with a shift symmetry. We show that, unlike generic scalar extended massive gravity models, these theories do not admit static, spherically symmetric black hole solutions until the theory parameters in the dRGT potential is fine-tuned. When fine-tuned, the geometry of the static, spherically symmetric black hole is necessarily that of general relativity and the quasi-dilaton field is constant across the spacetime. The fine-tuning and the no hair theorem apply to black holes with flat, anti-de Sitter or de Sitter asymptotics.
No hair theorem in quasi-dilaton massive gravity
Wu, De-Jun; Zhou, Shuang-Yong
2016-06-01
We investigate the static, spherically symmetric black hole solutions in the quasi-dilaton model and its generalizations, which are scalar extended dRGT massive gravity with a shift symmetry. We show that, unlike generic scalar extended massive gravity models, these theories do not admit static, spherically symmetric black hole solutions until the theory parameters in the dRGT potential are fine-tuned. When fine-tuned, the geometry of the static, spherically symmetric black hole is necessarily that of general relativity and the quasi-dilaton field is constant across the spacetime. The fine-tuning and the no hair theorem apply to black holes with flat, anti-de Sitter or de Sitter asymptotics.
R-Charged Black Holes and Holographic Optics
Phukon, Prabwal
2013-01-01
We analyze momentum dependent vector modes in the context of gauge theories dual to R-charged black holes in D=4, 5 and 7. For a variety of examples, the master variables are constructed, for which the linearized equations for the perturbations decouple. These allow for the computation of momentum dependent correlation functions. Away from the hydrodynamic limit, numerical analysis using the decoupled equations of motion is used to obtain the analogues of the Depine-Lakhtakia (DL) index. For specified ranges of frequencies, a negative index of refraction is seen to occur in all cases.
Numerical study of superradiant instability for charged stringy black hole-mirror system
Li, Ran
2015-01-01
We numerically study the superradiant instability of charged massless scalar field in the background of charged stringy black hole with mirror-like boundary condition. We compare the numerical result with the previous analytical result and show the dependencies of this instability upon various parameters of black hole charge $Q$, scalar field charge $q$, and mirror radius $r_m$. Especially, we have observed that imaginary part of BQN frequencies grows with the scalar field charge $q$ rapidly.
Numerical study of superradiant instability for charged stringy black hole-mirror system
Li, Ran; Zhao, Junkun
2015-01-01
We numerically study the superradiant instability of charged massless scalar field in the background of charged stringy black hole with mirror-like boundary condition. We compare the numerical result with the previous analytical result and show the dependencies of this instability upon various values of black hole charge Q, scalar field charge q, and mirror radius rm. Especially, we have observed that imaginary part of BQN frequencies grows with the scalar field charge q rapidly.
Numerical study of superradiant instability for charged stringy black hole–mirror system
Li, Ran; Zhao, Junkun
2015-01-01
We numerically study the superradiant instability of charged massless scalar field in the background of charged stringy black hole with mirror-like boundary condition. We compare the numerical result with the previous analytical result and show the dependencies of this instability upon various values of black hole charge Q , scalar field charge q , and mirror radius rm . Especially, we have observed that imaginary part of BQN frequencies grows with the scalar field charge q rapidly.
Numerical study of superradiant instability for charged stringy black hole–mirror system
Directory of Open Access Journals (Sweden)
Ran Li
2015-01-01
Full Text Available We numerically study the superradiant instability of charged massless scalar field in the background of charged stringy black hole with mirror-like boundary condition. We compare the numerical result with the previous analytical result and show the dependencies of this instability upon various values of black hole charge Q, scalar field charge q, and mirror radius rm. Especially, we have observed that imaginary part of BQN frequencies grows with the scalar field charge q rapidly.
Seiberg-Witten Instability of Various Topological Black Holes
Ong, Yen Chin
2013-01-01
We review the Seiberg-Witten instability of topological black holes in Anti-de Sitter space due to nucleation of brane-anti-brane pairs. We start with black holes in general relativity, and then proceed to discuss the peculiar property of topological black holes in Ho\\v{r}ava-Lifshitz gravity -- they have instabilities that occur at only finite range of distance away from the horizon. This behavior is not unique to black holes in Ho\\v{r}ava-Lifshitz theory, as it is also found in the relatively simple systems of charged black hole with dilaton hair that arise in low energy limit of string theory.
Charge Orbits of Extremal Black Holes in Five Dimensional Supergravity
Cerchiai, Bianca L; Marrani, Alessio; Zumino, Bruno
2010-01-01
We derive the U-duality charge orbits, as well as the related moduli spaces, of "large" and "small" extremal black holes in non-maximal ungauged Maxwell-Einstein supergravities with symmetric scalar manifolds in d=5 space-time dimensions. The stabilizer groups of the various classes of orbits are obtained by determining and solving suitable U-invariant sets of constraints, both in "bare" and "dressed" charges bases, with various methods. After a general treatment of attractors in real special geometry (also considering non-symmetric cases), the N=2 "magic" theories, as well as the N=2 Jordan symmetric sequence, are analyzed in detail. Finally, the half-maximal (N=4) matter-coupled supergravity is also studied in this context.
Thermodynamics of charged Lifshitz black holes with quadratic corrections
Bravo-Gaete, Moises
2015-01-01
In arbitrary dimension, we consider the Einstein-Maxwell Lagrangian supplemented by the more general quadratic-curvature corrections. For this model, we derive four classes of charged Lifshitz black hole solutions for which the metric function is shown to depend on a unique integration constant. The masses of these solutions are computed using the quasilocal formalism based on the relation established between the off-shell ADT and Noether potentials. Among these four solutions, three of them are interpreted as extremal in the sense that their mass vanishes identically. For the last family of solutions, the quasilocal mass and the electric charge both are shown to depend on the integration constant. Finally, we verify that the first law of thermodynamics holds for each solution and a Smarr formula is also established for the four solutions.
Holographic Superfluids and Superconductors in Dilaton-Gravity
Salvio, Alberto
2012-01-01
We investigate holographic models of superfluids and superconductors in which the gravitational theory includes a dilatonic field. Dilaton extensions are interesting as they allow us to obtain a better description of low temperature condensed matter systems. We focus on asymptotically AdS black hole configurations, which are dual to field theories with conformal ultraviolet behavior. A nonvanishing value of the dilaton breaks scale invariance in the infrared and is therefore compatible with the normal phase being insulating (or a solid in the fluid mechanical interpretation); indeed we find that this is the case at low temperatures and if one appropriately chooses the parameters of the model. Not only the superfluid phase transitions, but also the response to external gauge fields is analyzed. This allows us to study, among other things, the vortex phase and to show that these holographic superconductors are also of Type II. However, at low temperatures they can behave in a qualitatively different way compare...
Directory of Open Access Journals (Sweden)
Oda Kin-ya
2013-05-01
Full Text Available Both the ATLAS and CMS experiments at the LHC have reported the observation of the particle of mass around 125 GeV which is consistent to the Standard Model (SM Higgs boson, but with an excess of events beyond the SM expectation in the diphoton decay channel at each of them. There still remains room for a logical possibility that we are not seeing the SM Higgs but something else. Here we introduce the minimal dilaton model in which the LHC signals are explained by an extra singlet scalar of the mass around 125 GeV that slightly mixes with the SM Higgs heavier than 600 GeV. When this scalar has a vacuum expectation value well beyond the electroweak scale, it can be identified as a linearly realized version of a dilaton field. Though the current experimental constraints from the Higgs search disfavors such a region, the singlet scalar model itself still provides a viable alternative to the SM Higgs in interpreting its search results.
Time Delay in Gravitational Lensing by a Charged Black Hole of String Theory
Rubio, E A L
2003-01-01
We calculate the time delay between different relativistic images formed by the gravitational lensing produced by the Gibbons-Maeda-Garfinkle-Horowitz-Stromiger (GMGHS) charged black hole of heterotic string theory. Modeling the supermassive central objects of some galaxies as GMGHS black holes, numerical values of the time delays are estimated and compared with the correspondient Reissner-Nordstrom black holes . The time difference amounts to hours, thus being measurable and permiting to distinguish between General Relativity and String Theory charged black holes.
Brane solutions of gravity-dilaton-axion systems
Bergshoeff, E; Collinucci, A; Gran, U; Roest, D; Vandoren, S; Lukierski, J; Sorokin, D
2005-01-01
We consider general properties of brane solutions of gravity-dilaton-axion systems. We focus on the case of 7-branes and instantons. In both cases we show that besides the standard solutions there are new deformed solutions whose charges take value in any of the three conjugacy classes of SL(2, R).
Bianchi type I cosmologies in arbitrary dimensional dilaton gravities
Chen, Chiang-Mei; Harko, T.; Mak, M. K.
2000-12-01
We study the low energy string effective action with an exponential type dilaton potential and vanishing torsion in a Bianchi type I space-time geometry. In the Einstein and string frames the general solution of the gravitational field equations can be expressed in an exact parametric form. Depending on the values of the dilaton coupling constant and of the coefficient in the exponential, the obtained cosmological models can be generically divided into three classes, leading to both singular and non-singular behaviors. The effect of the potential on the time evolution of the mean anisotropy parameter is also considered in detail, and it is shown that a Bianchi type I universe isotropizes only in the presence of a dilaton field potential or a central deficit charge.
Properties of CFTs dual to charged BTZ black hole
Energy Technology Data Exchange (ETDEWEB)
Maity, Debaprasad, E-mail: debu@imsc.res.i [The Institute of Mathematical Sciences, Taramani, Chennai 600113 (India); Sarkar, Swarnendu, E-mail: ssarkar@physics.du.ac.i [Department of Physics and Astrophysics, University of Delhi, Delhi 110007 (India); Sathiapalan, B., E-mail: bala@imsc.res.i [The Institute of Mathematical Sciences, Taramani, Chennai 600113 (India); Shankar, R., E-mail: shankar@imsc.res.i [The Institute of Mathematical Sciences, Taramani, Chennai 600113 (India); Sircar, Nilanjan, E-mail: nilanjan@imsc.res.i [The Institute of Mathematical Sciences, Taramani, Chennai 600113 (India)
2010-11-11
We study properties of strongly coupled CFT's with non-zero background electric charge in 1+1 dimensions by studying the dual gravity theory-which is a charged BTZ black hole. Correlators of operators dual to scalars, gauge fields and fermions are studied at both T=0 and T{ne}0. In the T=0 case we are also able to compare with analytical results based on AdS{sub 2} and find reasonable agreement. In particular the correlation between log periodicity and the presence of finite spectral density of gapless modes is seen. The real part of the conductivity (given by the current-current correlator) also vanishes as {omega}{yields}0 as expected. The fermion Green's function shows quasiparticle peaks with approximately linear dispersion but the detailed structure is neither Fermi liquid nor Luttinger liquid and bears some similarity to a 'Fermi-Luttinger' liquid. This is expected since there is a background charge and the theory is not Lorentz or scale invariant. A boundary action that produces the observed non-Luttinger liquid like behavior (k-independent non-analyticity at {omega}=0) in the Green's function is discussed.
Superradiant instability of charged scalar field in stringy black hole mirror system
Li, Ran; Zhao, Junkun
2014-01-01
It has been shown that the mass of a charged scalar field in the background of a charged stringy black hole is never able to generate a potential well outside the event horizon to trap the superradiant modes. This is to say that the charged stringy black hole is stable against massive charged scalar perturbations. In this paper we will study the superradiant instability of the massless scalar field in the background of charged stringy black hole due to a mirror-like boundary condition. The an...
Non-Abelian magnetic black strings versus black holes
Mazharimousavi, S. Habib; Halilsoy, M.
2016-05-01
We present d+1 -dimensional pure magnetic Yang-Mills (YM) black strings (or 1-branes) induced by the d -dimensional Einstein-Yang-Mills-Dilaton black holes. The Born-Infeld version of the YM field makes our starting point which goes to the standard YM field through a limiting procedure. The lifting from black holes to black strings (with less number of fields) is done by adding an extra, compact coordinate. This amounts to the change of horizon topology from S^{d-2} to a product structure. Our black string in 5 dimensions is a rather special one, with uniform Hawking temperature and non-asymptotically flat structure. As the YM charge becomes large the string gets thinner to tend into a breaking point and transform into a 4-dimensional black hole.
On free energy of 2-d black hole in bosonic string theory
Kazakov, V A
2001-01-01
Trying to interpret recent matrix model results (hep-th/0101011) we discuss computation of classical free energy of exact dilatonic 2-d black hole from the effective action of string theory. The euclidean space-time action evaluated on the black hole background is divergent due to linear dilaton vacuum contribution, and its finite part depends on a subtraction procedure. The thermodynamic approach based on subtracting the vacuum contribution for fixed values of temperature and dilaton charge at the "wall" gives (as in the leading-order black hole case) S= M/T for the entropy and zero value for the free energy F. We suggest that in order to establish a correspondence with a non-vanishing matrix model result for F one may need an alternative reparametrization-invariant subtraction procedure using analogy with non-critical string theory (i.e. replacing the spatial coordinate by the dilaton field). The subtraction of the dilaton divergence then produces a finite value for the free energy. We also propose a micros...
$AdS_2$ holography is (non-)trivial for (non-)constant dilaton
Grumiller, Daniel; Vassilevich, Dmitri
2015-01-01
We study generic two-dimensional dilaton gravity with a Maxwell field and prove its triviality for constant dilaton boundary conditions, despite of the appearance of a Virasoro algebra with non-zero central charge. We do this by calculating the canonical boundary charges, which turn out to be trivial, and by calculating the quantum gravity partition function, which turns out to be unity. We show that none of the following modifications changes our conclusions: looser boundary conditions, non-linear interactions of the Maxwell field with the dilaton, inclusion of higher spin fields, inclusion of generic gauge fields. Finally, we consider specifically the charged Jackiw--Teitelboim model, whose holographic study was pioneered by Hartman and Strominger, and show that it is non-trivial for certain linear dilaton boundary conditions. We calculate the entropy from the Euclidean path integral, using Wald's method and exploiting the chiral Cardy formula. The macroscopic and microscopic results for entropy agree with ...
Joule-Thomson expansion of the charged AdS black holes
Ökcü, Özgür; Aydıner, Ekrem
2017-01-01
In this paper, we study Joule-Thomson effects for charged AdS black holes. We obtain inversion temperatures and curves. We investigate similarities and differences between van der Waals fluids and charged AdS black holes for the expansion. We obtain isenthalpic curves for both systems in the T- P plane and determine the cooling-heating regions.
Joule-Thomson Expansion of Charged AdS Black Holes
Ökcü, Özgür
2016-01-01
In this paper, we study Joule-Thomson effects for charged AdS black holes. We obtain inversion temperatures and curves. We investigate similarities and differences between van der Waals fluids and charged AdS black holes for the expansion. We obtain isenthalpic curves for both systems in $T-P$ plane and determine the cooling-heating regions.
Near horizon data and physical charges of extremal AdS black holes
Astefanesei, D.; Banerjee, N.; Dutta, S.
2011-01-01
We compute the physical charges and discuss the properties of a large class of five-dimensional extremal AdS black holes by using the near horizon data. Our examples include baryonic and electromagnetic black branes, as well as supersymmetric spinning black holes. In the presence of the gauge Chern–
Black Holes as Conformal Field Theories on Horizons
Halyo, Edi
2015-01-01
We show that any nonextreme black hole can be described by a state with $L_0=E_R$ in a $D=2$ chiral conformal field theory with central charge $c=12E_R$ where $E_R$ is the dimensionless Rindler energy of the black hole. The theory lives in the very near horizon region, i.e. around the origin of Rindler space. Black hole hair is the momentum along the Euclidean dimensionless Rindler time direction. As evidence, we show that $D$--dimensional Schwarzschild black holes and $D=2$ dilatonic ones that are obtained from them by spherical reduction are described by the same conformal field theory states.
Charged Rotating AdS Black Holes with Chern-Simons coupling
Mir, Mozhgan
2016-01-01
We obtain a perturbative solution for rotating charged black holes in 5-dimensional Einstein-Maxwell-Chern-Simons theory with a negative cosmological constant. We start from a small undeformed Kerr-AdS solution and use the electric charge as a perturbative parameter to build up black holes with equal-magnitude angular momenta up to forth order. These black hole solutions are described by three parameters, the charge, horizon radius and horizon angular velocity. We determine the physical quantities of these black holes and study their dependence on the parameters of black holes and arbitrary Chern-Simons coefficient. In particular, for values of CS coupling constant beyond its supergravity amount, due to a rotational instability, counterrotating black holes arise. Also the rotating solutions appear to have vanishing angular momenta and do not manifest uniquely by their global charges.
Holographic phase transitions from higgsed, non abelian charged black holes
Giordano, Gaston L
2015-01-01
We find solutions of a gravity-Yang-Mills-Higgs theory in four dimensions that represent asymptotic anti-de Sitter charged black holes with partial/full gauge symmetry breaking. We then apply the AdS/CFT correspondence to study the strong coupling regime of a $2+1$ quantum field theory at temperature $T$ and finite chemical potential, which undergoes transitions to phases exhibiting the condensation of a composite charged vector operator below a critical temperature $T_c$, presumably describing $p+ip/p$-wave superconductors. In the case of $p+ip$-wave superconductors the transitions are always of second order. But for $p$-wave superconductors we determine the existence of a critical value $\\alpha_c$ of the gravitational coupling (for fixed Higgs v.e.v. parameter $\\hat m_W$) beyond which the transitions become of first order. As a by-product, we show that the $p$-wave phase is energetically favored over the $p+ip$ one, for any values of the parameters. Finally we find the ground state solutions corresponding t...
Electrically charged Kerr black holes with scalar hair
Delgado, Jorge F M; Radu, Eugen; Runarsson, Helgi
2016-01-01
We construct electrically charged Kerr black holes (BHs) with scalar hair. Firstly, we take an uncharged scalar field, interacting with the electromagnetic field only indirectly, via the background metric. The corresponding family of solutions, dubbed Kerr-Newman BHs with ungauged scalar hair, reduces to (a sub-family of) Kerr-Newman BHs in the limit of vanishing scalar hair and to uncharged rotating boson stars in the limit of vanishing horizon. It adds one extra parameter to the uncharged solutions: the total electric charge. This leading electromagnetic multipole moment is unaffected by the scalar hair and can be computed by using Gauss's law on any closed 2-surface surrounding (a spatial section of) the event horizon. By contrast, the first sub-leading electromagnetic multipole -- the magnetic dipole moment --, gets suppressed by the scalar hair, such that the gyromagnetic ratio is always smaller than the Kerr-Newman value ($g=2$). Secondly, we consider a gauged scalar field and obtain a family of Kerr-Ne...
Sphaleron in the dilatonic electroweak theory
Karczewska, D
1996-01-01
A numerical study of static, spherically symmetric sphaleron solutions in the standard model coupled to the dilaton field is presented. We show that sphaleron is surrounded by strong dilaton cloud which vanishes inside the sphaleron.
Non-Perturbative Two-Dimensional Dilaton Gravity
Mikovic, A
1993-01-01
We present a review of the canonical quantization approach to the problem of non-perturbative 2d dilaton gravity. In the case of chiral matter we describe a method for solving the constraints by constructing a Kac-Moody current algebra. For the models of interest, the relevant Kac-Moody algebras are based on SL(2,R) X U(1) group and on an extended 2d Poincare group. As a consequence, the constraints become free-field Virasoro generators with background charges. We argue that the same happens in the non-chiral case. The problem of the corresponding BRST cohomology is discussed as well as the unitarity of the theory. One can show that the theory is unitary by chosing a physical gauge, and hence the problem of transitions from pure into mixed sates is absent. Implications for the physics of black holes are discussed. (Based on the talks presented at Trieste conference on Gauge Theories, Applied Supersymmetry and Quantum Gravity, May 1993 and at Danube '93 Workshop, Belgrade, Yugoslavia, June 1993)
Superradiant instability of charged scalar field in stringy black hole mirror system
Energy Technology Data Exchange (ETDEWEB)
Li, Ran; Zhao, Junkun [Henan Normal University, Department of Physics, Xinxiang (China)
2014-09-15
It has been shown that the mass of a charged scalar field in the background of a charged stringy black hole is never able to generate a potential well outside the event horizon to trap the superradiant modes. This is to say that the charged stringy black hole is stable against massive charged scalar perturbations. In this paper we will study the superradiant instability of the massless scalar field in the background of charged stringy black hole due to a mirror-like boundary condition. The analytical expression of the frequencies of unstable superradiant modes is derived by using the asymptotic matching method. It is also pointed out that the black hole mirror system becomes extremely unstable for a large charge q of the scalar field and a small mirror radius r{sub m}. (orig.)
Power law of shear viscosity in Einstein-Maxwell-Dilaton-Axion model
Ling, Yi; Xian, Zhuoyu; Zhou, Zhenhua
2017-02-01
We construct charged black hole solutions with hyperscaling violation in the infrared (IR) region in Einstein-Maxwell-Dilaton-Axion theory and investigate the temperature behavior of the ratio of holographic shear viscosity to the entropy density. When translational symmetry breaking is relevant in the IR, the power law of the ratio is verified numerically at low temperature T, namely, η/s ∼ T κ , where the values of exponent κ coincide with the analytical results. We also find that the exponent κ is not affected by irrelevant current, but is reduced by the relevant current. Supported by National Natural Science Foundation of China (11275208, 11575195), Opening Project of Shanghai Key Laboratory of High Temperature Superconductors (14DZ2260700) and Jiangxi Young Scientists (JingGang Star) Program and 555 Talent Project of Jiangxi Province
Dilaton constraints and LHC prospects
Coleppa, Baradhwaj; Logan, Heather E
2011-01-01
The Standard Model Higgs searches using the first 1-2 fb-1 of LHC data can be used to put interesting constraints on new scalar particles other than the Higgs. We investigate one such scenario in which electroweak symmetry is broken via strongly coupled conformal dynamics. This scenario contains a neutral scalar dilaton---the Goldstone boson associated with spontaneously broken scale invariance---with a mass below the conformal symmetry breaking scale and couplings to Standard Model particles similar (but not identical) to those of the Standard Model Higgs boson. We translate the LEP and LHC Higgs limits to constrain the dilaton mass and conformal breaking scale. The conformal breaking scale f is constrained to be above 1 TeV for dilaton masses between 145 and 600 GeV, though it can be as low as 400 GeV for dilaton masses below 110 GeV. We also show that (i) a dilaton chi with mass below 110 GeV and consistent with the LEP constraints can appear in gg --> chi --> gamma gamma with a rate up to ~10 times the co...
p-wave superconductors in dilaton gravity
Fan, ZhongYing
2013-01-01
In this paper, we study peculiar properties of p-wave superconductors in dilaton gravity. The scale invariance of the bulk geometry is effectively broken due to the existence of dilaton. By coupling the dilaton to the non-Abelian gauge field, i.e., $-\\frac14 e^{-\\beta \\Phi} F^a_{\\mu\
Entropy spectrum of charged BTZ black holes in massive gravity's rainbow
Panah, Behzad Eslam
2016-01-01
Regarding the significant interests in massive gravity's rainbow and also BTZ black holes, we apply the formalism introduced by Jiang and Han in order to investigate the quantization of the entropy of black holes. We show that the entropy of BTZ black holes in massive gravity's rainbow is quantized with equally spaced spectra and it depends on the value of the parameters of this black hole such as; massive parameters, electrical charge, the cosmological constant and also rainbow functions.
Electrostatics in the Surroundings of a Topologically Charged Black Hole in the Brane
Directory of Open Access Journals (Sweden)
Alexis Larrañaga
2014-01-01
Full Text Available We determine the expression for the electrostatic potential generated by a point charge held stationary in the topologically charged black hole spacetime arising from the Randall-Sundrum II braneworld model. We treat the static electric point charge as a linear perturbation on the black hole background and an expression for the electrostatic multipole solution is given: PACS: 04.70.-s, 04.50.Gh, 11.25.-w, 41.20.-q, 41.90.+e.
A Strongly Coupled Anisotropic Fluid From Dilaton Driven Holography
Jain, Sachin; Sen, Kallol; Sinha, Aninda; Trivedi, Sandip P
2014-01-01
We consider a system consisting of $5$ dimensional gravity with a negative cosmological constant coupled to a massless scalar, the dilaton. We construct a black brane solution which arises when the dilaton satisfies linearly varying boundary conditions in the asymptotically $AdS_5$ region. The geometry of this black brane breaks rotational symmetry while preserving translational invariance and corresponds to an anisotropic phase of the system. Close to extremality, where the anisotropy is big compared to the temperature, some components of the viscosity tensor become parametrically small compared to the entropy density. We study the quasi normal modes in considerable detail and find no instability close to extremality. We also obtain the equations for fluid mechanics for an anisotropic driven system in general, working upto first order in the derivative expansion for the stress tensor, and identify additional transport coefficients which appear in the constitutive relation. For the fluid of interest we find t...
Binary compact object mergers in Einstein-Maxwell-Dilaton theories
Hirschmann, Eric; Lehner, Luis; Liebling, Steve; Palenzuela, Carlos
2017-01-01
We present work on the dynamics and gravitational wae emission of binary black holes in a modified theory of gravity. Our particular model is inspired by low energy string theory and includes additional matter fields, such as a dilaton, not necessarily present in vacuum general relativity. We consider deviations from standard predictions for gravitational wave signatures and examine alternative scalar and electromagnetic channels for emission.
Hawking Radiation via Damour-Ruffini Method in Squashed Charged Rotating Kaluza-Klein Black Holes
Hu, Ji-Wan; Wu, Jing-He; Liu, Xian-Ming
2017-02-01
Using the Damour-Ruffini method, Hawking radiation of charged particles from squashed charged rotating five-dimensional Kaluza-Klein black holes is investigated extensively. Under the generalized tortoise coordinate transformation, Hawking temperature of the black holes is calculated by using charged scalar particles and Dirac fermions respectively. We find that the obtained Hawking temperature for charged Dirac fermions is the same as for charged scalar particles. What's more, the spectrum of Hawking radiation contains the information of the size of the extra dimension, which could provide insight for further investigation of large extra dimensions in the future.
Charge Loss (or the Lack Thereof) for AdS Black Holes
Ong, Yen Chin
2014-01-01
The evolution of evaporating charged black holes is complicated to model in general, but is nevertheless important since the hints to the Information Loss Paradox and its recent firewall incarnation may lie in understanding more generic geometries than that of Schwarzschild spacetime. Fortunately, for sufficiently large asymptotically flat Reissner-Nordstrom black holes, the evaporation process can be modeled via a system of coupled linear ordinary differential equations, with charge loss rate governed by Schwinger pair-production process. The same model can be generalized to study the evaporation of AdS Reissner-Nordstrom black holes with flat horizon. It was recently found that such black holes always evolve towards extremality since charge loss is inefficient. This property is completely opposite to the asymptotically flat case in which the black hole eventually loses its charges and tends towards Schwarzschild limit. We clarify the underlying reason for this different behavior.
Holographic phase transitions from higgsed, non abelian charged black holes
Giordano, Gastón L.; Lugo, Adrián R.
2015-07-01
We find solutions of a gravity-Yang-Mills-Higgs theory in four dimensions that represent asymptotic anti-de Sitter charged black holes with partial/full gauge symme-try breaking. We then apply the AdS/CFT correspondence to study the strong coupling regime of a 2 + 1 quantum field theory at temperature T and finite chemical potential, which undergoes transitions to phases exhibiting the condensation of a composite charged vector operator below a critical temperature T c , presumably describing p + ip/p-wave su-perconductors. In the case of p + ip-wave superconductors the transitions are always of second order. But for p-wave superconductors we determine the existence of a critical value αc of the gravitational coupling (for fixed Higgs v.e.v. parameter ) beyond which the transitions become of first order. As a by-product, we show that the p-wave phase is energetically favored over the p + ip one, for any values of the parameters. We also find the ground state solutions corresponding to zero temperature. Such states are described by domain wall geometries that interpolate between AdS 4 spaces with different light veloc-ities, and for a given , they exist below a critical value of the coupling. The behavior of the order parameter as function of the gravitational coupling near the critical coupling suggests the presence of second order quantum phase transitions. We finally study the dependence of the solution on the Higgs coupling, and find the existence of a critical value beyond which no condensed solution is present.
Superradiant instability of the charged scalar field in stringy black hole mirror system
Li, Ran
2014-01-01
It has been shown that the mass of the scalar field in the charged stringy black hole is never able to generate a potential well outside the event horizon to trap the superradiant modes. This is to say that the charged stringy black hole is stable against the massive charged scalar perturbation. In this paper we will study the superradiant instability of the massless scalar field in the background of charged stringy black hole due to a mirror-like boundary condition. The analytical expression of the unstable superradiant modes is derived by using the asymptotic matching method. It is also pointed out that the black hole mirror system becomes extremely unstable for a large charge $q$ of scalar field and the small mirror radius $r_m$.
Conserved charges, surface degrees of freedom, and black hole entropy
Seraj, Ali
2016-01-01
In this thesis, we study the Hamiltonian and covariant phase space description of gravitational theories. The phase space represents the allowed field configurations and is accompanied by a closed nondegenerate 2 form- the symplectic form. We will show that local/gauge symmetries of the action fall into two different categories in the phase space formulation. Those corresponding to constraints in the phase space, and those associated with nontrivial conserved charges. We argue that while the former is related to redundant gauge degrees of freedom, the latter leads to physically distinct states of the system, known as surface degrees of freedom and can induce a lower dimensional dynamics on the system. These ideas are then implemented to build the phase space of specific gravitational systems: 1) asymptotically AdS3 spacetimes, and 2) near horizon geometries of extremal black holes (NHEG) in arbitrary dimension. In the AdS3 phase space, we show that Brown-Henneaux asymptotic symmetries can be extended inside t...
The generalization of charged AdS black hole specific volume and number density
Wang, Zi-Liang; He, Miao; Fang, Chao; Sun, Dao-Quan; Deng, Jian-Bo
2017-04-01
In this paper, by proposing a generalized specific volume, we restudy the P- V criticality of charged AdS black holes in the extended phase space. The results show that most of the previous conclusions can be generalized without change, but the ratio {\\tilde{ρ }}_c should be 3 {\\tilde{α }}/16 in general case. Further research on the thermodynamical phase transition of black hole leads us to a natural interpretation of our assumption, and more black hole properties can be generalized. Finally, we study the number density for charged AdS black hole in higher dimensions, the results show the necessity of our assumption.
Anisotropic plasmas from axion and dilaton deformations
Donos, Aristomenis; Sosa-Rodriguez, Omar
2016-01-01
We construct black hole solutions of type IIB supergravity that are holographically dual to anisotropic plasmas arising from deformations of an infinite class of four-dimensional CFTs. The CFTs are dual to $AdS_5\\times X_5$, where $X_5$ is an Einstein manifold, and the deformations involve the type IIB axion and dilaton, with non-trivial periodic dependence on one of the spatial directions of the CFT. At low temperatures the solutions approach smooth domain wall solutions with the same $AdS_5\\times X_5$ solution appearing in the far IR. For sufficiently large deformations an intermediate scaling regime appears which is governed by a Lifshitz-like scaling solution. We calculate the DC thermal conductivity and some components of the shear viscosity tensor.
Anisotropic plasmas from axion and dilaton deformations
Donos, Aristomenis; Gauntlett, Jerome P.; Sosa-Rodriguez, Omar
2016-11-01
We construct black hole solutions of type IIB supergravity that are holographically dual to anisotropic plasmas arising from deformations of an infinite class of four-dimensional CFTs. The CFTs are dual to AdS 5 × X 5, where X 5 is an Einstein manifold, and the deformations involve the type IIB axion and dilaton, with non-trivial periodic dependence on one of the spatial directions of the CFT. At low temperatures the solutions approach smooth domain wall solutions with the same AdS 5 × X 5 solution appearing in the far IR. For sufficiently large deformations an intermediate scaling regime appears which is governed by a Lifshitz-like scaling solution. We calculate the DC thermal conductivity and some components of the shear viscosity tensor.
Strong Gravitational Lensing in a Charged Squashed Kaluza- Klein G\\"{o}del Black hole
Sadeghi, J
2013-01-01
In this paper we investigate the strong gravitational lansing in a charged squashed Kaluza-Klein G\\"{o}del black hole. The deflection angle is considered by the logarithmic term proposed by Bozza et al. Then we study the variation of deflection angle and its parameters $\\bar{a}$ and $\\bar{b}$ . We suppose that the supermassive black hole in the galaxy center can be considered by a charged squashed Kaluza-Klein black hole in a G\\"{o}del background and by relation between lensing parameters and observables we estimate the observables for different values of charge, extra dimension and G\\"{o}del parameters.
Scalar Perturbations on the background of Linearly and Nonlinearly Charged BTZ Black Holes
Tang, Zi-Yu; Zangeneh, Mahdi Kord; Wang, Bin; Saavedra, Joel
2016-01-01
We investigate the spacetime properties of BTZ black holes in Maxwell field and BornInfeld field and find rich properties in the spacetime structures when the model parameters vary. Employing the Landau-Lifshitz theory, we examine the thermodynamical phase transition in the charged BTZ holes. We further study the dynamical perturbation in the background of the charged BTZ black holes and find different properties of dynamical perturbations for the extreme and nonextreme charged BTZ black holes, which can serve as a new physical signal to indicate the phase transition between them.
Coupled dilaton and electromagnetic field in cylindrically symmetric spacetime
Indian Academy of Sciences (India)
A Banerjee; S Chatterjee; Tanwi Ghosh
2000-03-01
An exact solution is obtained for coupled dilaton and electromagnetic ﬁeld in a cylindrically symmetric spacetime where an axial magnetic ﬁeld as well as a radial electric ﬁeld both are present. Depending on the choice of the arbitrary constants our solution reduces either to dilatonic gravity with pure electric ﬁeld or to that with pure magnetic ﬁeld. In the ﬁrst case we have a curvature singularity at a ﬁnite distance from the axis indicating the existence of the boundary of a charged cylinder which may represent the source of the electric ﬁeld. For the second case we have a singularity on the axis. When the dilaton ﬁeld is absent the electromagnetic ﬁeld disappears in both the cases. Whereas the contrary is not true. It is further shown that light rays except for those proceeding in the radial direction are either trapped or escape to inﬁnity depending on the magnitudes of certain constant parameters as well as on the nature of the electromagnetic ﬁeld. Nature of circular geodesics is also studied in the presence of dilaton ﬁeld in the cylindrically symmetric spacetime.
Institute of Scientific and Technical Information of China (English)
无
2010-01-01
In this paper,we extend fermions tunneling radiation to the case of five-dimensional charged black holes by introducing a set of appropriate matrices γμ for general covariant Dirac equation of 1/2 spin charged Dirac particles in the electromagnetic field.It is expected that our result can strengthen the validity and power of the tunneling method.We take the charged Gdel black holes in minimal five-dimensional gauged supergravity for example in order to present a reasonable extension of the tunneling method.As a result,we get fermions tunneling probability of the black hole and the Hawking temperature near the event horizon.
Phases of R-charged Black Holes, Spinning Branes and Strongly Coupled Gauge Theories
Cvetic, M; Cvetic, Mirjam; Gubser, Steven S.
1999-01-01
We study the thermodynamic stability of charged black holes in gauged supergravity theories in D=5, D=4 and D=7. We find explicitly the location of the Hawking-Page phase transition between charged black holes and the pure anti-de Sitter space-time, both in the grand-canonical ensemble, where electric potentials are held fixed, and in the canonical ensemble, where total charges are held fixed. We also find the explicit local thermodynamic stability constraints for black holes with one non-zero charge. In the grand-canonical ensemble, there is in general a region of phase space where neither the anti-de Sitter space-time is dynamically preferred, nor are the charged black holes thermodynamically stable. But in the canonical ensemble, anti-de Sitter space-time is always dynamically preferred in the domain where black holes are unstable. We demonstrate the equivalence of large R-charged black holes in D=5, D=4 and D=7 with spinning near-extreme D3-, M2- and M5-branes, respectively. The mass, the charges and the ...
Holographic Renormalization of Einstein-Maxwell-Dilaton Theories
Kim, Bom Soo
2016-01-01
We generalize the boundary value problem with a mixed boundary condition that involves the gauge and scalar fields in the context of Einstein-Maxwell-Dilaton theories. In particular, the expectation value of the dual scalar operator can be a function of the expectation value of the current operator. The properties are prevalent in a fixed charge ensemble because the conserved charge is shared by both fields through the dilaton coupling, which is also responsible for non-Fermi liquid properties. We study the on-shell action and the stress energy tensor to note practical importances of the boundary value problem. In the presence of the scalar fields, physical quantities are not fully fixed due to the finite boundary terms that manifest in the massless scalar or the scalar with mass saturating the Breitenlohner-Freedman bound.
Instability of Charged Gauss-Bonnet Black Hole in de Sitter Spacetime at Large $D$
Chen, Bin
2016-01-01
We study the stabilities of (A)dS charged Gauss-Bonnet(GB) black holes in the large $D$ dimensions. After integrating the equation of motion with respect to the radial direction, we obtain the effective equations at large $D$ to describe the nonlinear dynamical deformations of the black hole. From the perturbation analysis of the effective equations, we get the analytic expressions of the frequencies for the quasinormal modes of scalar type. Furthermore we show that the charged GB black hole becomes unstable only if the cosmological constant is positive, otherwise the black hole is always stable. At the onset of instabilities there is a non-trivial static zero-mode perturbation, which suggests the existence of a new non-spherical symmetric solution branch of static dS charged GB black holes. We construct the non-spherical symmetric static solution of the large $D$ effective equations explicitly.
Nonlinear Evolution and Final Fate of Charged Anti-de Sitter Black Hole Superradiant Instability.
Bosch, Pablo; Green, Stephen R; Lehner, Luis
2016-04-08
We describe the full nonlinear development of the superradiant instability for a charged massless scalar field coupled to general relativity and electromagnetism, in the vicinity of a Reissner-Nordström-anti-de Sitter black hole. The presence of the negative cosmological constant provides a natural context for considering perfectly reflecting boundary conditions and studying the dynamics as the scalar field interacts repeatedly with the black hole. At early times, small superradiant perturbations grow as expected from linearized studies. Backreaction then causes the black hole to lose charge and mass until the perturbation becomes nonsuperradiant, with the final state described by a stable hairy black hole. For large gauge coupling, the instability extracts a large amount of charge per unit mass, resulting in greater entropy increase. We discuss the implications of the observed behavior for the general problem of superradiance in black hole spacetimes.
Charged Matter Tests of Cosmic Censorship for Extremal and Nearly-Extremal Black Holes
Sorce, Jonathan; Wald, Robert
2017-01-01
We investigate scenarios in which adding electrically charged matter to a black hole may cause it to become over-extremal, violating cosmic censorship. It has previously been shown that when the matter is localized as a point particle, no violation occurs for extremal black holes to lowest nonvanishing order in the particle's charge and mass. However, recent work has suggested that violations may be possible when the black hole deviates from extremality. We show that these potential violations always occur above lowest nonvanishing order, and conclude that no lowest-order violation can occur in the nearly-extremal case unless a violation also occurs in the extremal case. We also extend the previous results on point particles to show that no violations occur to second order in charge when an arbitrary charged matter configuration is added to an extremal Kerr black hole, provided only that the matter satisfies the null energy condition.
On The Phase Structure and Thermodynamic Geometry of R-Charged Black Holes
Sahay, Anurag; Sengupta, Gautam
2010-01-01
We study the phase structure and equilibrium state space geometry of R-charged black holes in $D = 5$, 4 and 7 and the corresponding rotating $D3$, $M2$ and $M5$ branes. For various charge configuratins of the compact black holes in the canonical ensemble we demonstrate new liquid-gas like phase coexistence behaviour culminating in second order critical points. The critical exponents turn out to be the same as that of four dimensional asymptotically AdS black holes in Einstein Maxwell theory. We further establish that the regions of stability for R-charged black holes are, in some cases, more constrained than is currently believed, due to properties of some of the response coefficients. The equilibrium state space scalar curvature is calculated for various charge configurations, both for the case of compact as well as flat horizons and its asymptotic behaviour with temperature is established.
Conformally coupled scalar black holes admit a flat horizon due to axionic charge
Bardoux, Yannis; Charmousis, Christos
2012-01-01
Static, charged black holes in the presence of a negative cosmological constant and with a planar horizon are found in four dimensions. The solutions have scalar secondary hair. We claim that these constitute the planar version of the Martinez-Troncoso-Zanelli black holes, only known up to now for a curved event horizon in four dimensions. Their planar version is rendered possible due to the presence of two, equal and homogeneously distributed, axionic charges dressing the flat horizon. The solutions are presented in the conformal and minimal frame and their basic properties and thermodynamics analysed. Entertaining recent applications to holographic superconductors, we expose two branches of solutions: the undressed axionic Reissner-Nordstrom-AdS black hole, and the novel black hole carrying secondary hair. We show that there is a critical temperature at which the (bald) axionic Reissner-Nordstrom-AdS black hole undergoes a second order phase transition to the hairy black hole spontaneously acquiring scalar ...
Extremal Black Hole Entropy from Horizon Conformal Field Theories
Halyo, Edi
2015-01-01
We show that the entropy of extremal $D=4$ Reissner--Nordstrom black holes can be computed from horizon CFTs with central charges and conformal weights fixed by the dimensionless Rindler energy. This is possible in the simultaneous extremal and near horizon limit of the black hole which takes the geometry to an $AdS_2$ Rindler space with finite temperature. The CFT description of dilatonic $AdS_2$ black holes, obtained from extremal ones by dimensional reduction, lead to exactly the same CFT states.
Minimal Dilaton Model and the Diphoton Excess
Agarwal, Bakul; Mohan, Kirtimaan A
2016-01-01
In light of the recent 750 GeV diphoton excesses reported by the ATLAS and CMS collaborations, we investigate the possibility of explaining this excess using the Minimal Dilaton Model. We find that this model is able to explain the observed excess with the presence of additional top partner(s), with same charge as the top quark, but with mass in the TeV region. First, we constrain model parameters using in addition to the 750 GeV diphoton signal strength, precision electroweak tests, single top production measurements, as well as Higgs signal strength data collected in the earlier runs of the LHC. In addition we discuss interesting phenomenolgy that could arise in this model, relevant for future runs of the LHC.
Black branes in AdS: BPS bounds and asymptotic charges
Energy Technology Data Exchange (ETDEWEB)
Hristov, K. [Institute for Theoretical Physics and Spinoza Institute, Utrecht University, 3508 TD Utrecht (Netherlands); Faculty of Physics, Sofia University, Sofia 1164 (Bulgaria); Toldo, C.; Vandoren, S. [Institute for Theoretical Physics and Spinoza Institute, Utrecht University, 3508 TD Utrecht (Netherlands)
2012-09-15
We focus on black branes and toroidal black holes in N = 2 gauged supergravities that asymptote to AdS{sub 4}, and derive formulas for the mass and central charge densities. We derive the corresponding BPS bound from the superalgebra of the asymptotic vacuum and illustrate our procedure with explicit examples of genuine black brane solutions with non-trivial scalars. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)
Charged BTZ black holes in the context of massive gravity's rainbow
Hendi, S H; Upadhyay, S; Panah, B Eslam
2016-01-01
Regarding the significant interests in thermodynamics of black objects, we examine charged BTZ black holes. We consider massive gravity context with an energy dependent spacetime to enrich the results. In addition, we consider all the constants as energy dependant ones. We investigate thermodynamic properties of the solutions by calculating the heat capacity and free energy. We also analyze thermal stability and study the possibility of Hawking-Page phase transition. At last, we study geometrical thermodynamics of these black holes.
Cotaescu, Ion I; Sporea, Ciprian
2016-01-01
The asymptotic form of the Dirac spinors in the field of the Reissner-Nordstrom black hole are derived for the scattering states (with $E>mc^2$) obtaining the phase shifts of the partial wave analysis of the Dirac fermions scattered from charged black holes. The elastic scattering and the absorption are studied giving analytic formulas for the partial amplitudes and cross sections.
Stability of the extremal Reissner-Nordstrom black hole to charged scalar perturbations
Hod, Shahar
2013-01-01
The stability of Reissner-Nordstrom black holes to neutral (gravitational and electromagnetic) perturbations was established almost four decades ago. However, the stability of these charged black holes under charged perturbations has remained an open question due to the well-known phenomena of superradiant scattering: A charged scalar field impinging on a charged Reissner-Nordstrom black hole can be amplified as it scatters off the hole. If the incident field has a non-zero rest mass, then the mass term effectively works as a mirror, preventing the energy extracted from the hole from escaping to infinity. One may suspect that such superradiant amplification of charged fields in Reissner-Nordstrom spacetimes may lead to an instability of these charged black holes (in as much the same way that rotating Kerr black holes are unstable under rotating scalar perturbations). However, we show here that, for extremal Reissner-Nordstrom black holes, the two conditions which are required in order to trigger a possible su...
Thermodynamics of (2 +1 )-dimensional charged black holes with power-law Maxwell field
Dehghani, M.
2016-11-01
In this work, the three-dimensional nonlinearly charged black holes have been considered with a power-law modified electromagnetic theory. The black hole solutions to Einstein's three-dimensional field equations with a negative cosmological constant have been constructed in the presence of power-law nonlinear electrodynamics. Through the physical and mathematical interpretation of the solutions, a new class of asymptotically anti-de Sitter (AdS) black hole solutions has been introduced. The area law, surface gravity, and Gauss's law are utilized to obtain the entropy, temperature, and electric charge of the new AdS black holes, respectively. The quasilocal mass of the solutions has been calculated based on the counterterm method. A Smarr-type formula for the mass as a function of entropy and charge has been obtained. It has been shown that the thermodynamical quantities satisfy the first law of thermodynamics for the new AdS black holes. Also, it has been found that in order for the Smarr mass formula to be compatible with the first law of black hole thermodynamics, the cosmological parameter Λ should be treated as a thermodynamical variable and the generalized first law of thermodynamics has been introduced. Through the canonical ensemble method, the black hole remnant or phase transitions have been investigated regarding the black hole heat capacity. It has been found that the AdS black hole solutions we just obtained are thermodynamically stable.
On dilatons and the LHC diphoton excess
Megías, Eugenio; Pujolàs, Oriol; Quirós, Mariano
2016-05-01
We study soft wall models that can embed the Standard Model and a naturally light dilaton. Exploiting the full capabilities of these models we identify the parameter space that allows to pass Electroweak Precision Tests with a moderate Kaluza-Klein scale, around 2 TeV. We analyze the coupling of the dilaton with Standard Model (SM) fields in the bulk, and discuss two applications: i) Models with a light dilaton as the first particle beyond the SM pass quite easily all observational tests even with a dilaton lighter than the Higgs. However the possibility of a 125 GeV dilaton as a Higgs impostor is essentially disfavored; ii) We show how to extend the soft wall models to realize a 750 GeV dilaton that could explain the recently reported diphoton excess at the LHC.
Dilaton and dynamical fermion mass generation
Energy Technology Data Exchange (ETDEWEB)
Hung, P.Q.; Zoupanos, G.
1987-05-21
In gauge theories with a hierarchy of mass scales there might appear a pseudo-Goldstone boson, the dilaton, resulting from the spontaneous breaking of scale symmetry. In addition light pseudoscalar bosons (axions) are expected in this class of models. We show that dynamical generation of fermion masses in these theories and the existence of a dilaton lead to unacceptably high axion masses. Therefore a dynamical fermion mass generation mechanism and a dilaton cannot coexist in a large class of such gauge theories.
Entropy/Area spectra of the charged black hole from quasinormal modes
Wei, Shao-Wen; Yang, Ke; Zhong, Yuan
2010-01-01
With the new physical interpretation of quasinormal modes proposed by Maggiore, the quantum area spectra of black holes have been investigated recently. It is shown that, the area spectrum for a non-rotating black hole with no charge is equidistant. While, for a rotating black hole, it is non-equidistant and depends on the angle momentum $J$. So, it is worth to investigate the area spectrum for a charged black hole. Following the Kunstatter's method, we obtain the area spectrum and entropy spectrum of the charged Garfinkle-Horowitz-Strominger black hole, originated from the effective action that emerges in the low-energy of string theory. Both the area spectrum and entropy spectrum are found to be equally spaced and do not depend on the charge $q$, which is different from that of the rotating black hole. Combing with possible observational data from gravity waves, we hope our results can give us answers to the open questions such as the black hole entropy.
Stability of black holes in Einstein-charged scalar field theory in a cavity
Dolan, Sam R; Winstanley, Elizabeth
2015-01-01
Can a black hole that suffers a superradiant instability evolve towards a 'hairy' configuration which is stable? We address this question in the context of Einstein-charged scalar field theory. First, we describe a family of static black hole solutions which possess charged scalar-field hair confined within a mirror-like boundary. Next, we derive a set of equations which govern the linear, spherically symmetric perturbations of these hairy solutions. We present numerical evidence which suggests that, unlike the vacuum solutions, the (single-node) hairy solutions are stable under linear perturbations. Thus, it is plausible that stable hairy black holes represent the end-point of the superradiant instability of electrically-charged Reissner-Nordstrom black holes in a cavity; we outline ways to explore this hypothesis.
Thermodynamics of R-charged Black Holes in AdS(5) From Effective Strings
Gubser, S S; Gubser, Steven S.; Heckman, Jonathan J.
2004-01-01
It is well known that the thermodynamics of certain near-extremal black holes in asymptotically flat space can be lifted to an effective string description created from the intersection of D-branes. In this paper we present evidence that the semiclassical thermodynamics of near-extremal R-charged black holes in AdS(5)xS(5) is described in a similar manner by effective strings created from the intersection of giant gravitons on the S(5). We also present a free fermion description of the supersymmetric limit of the one-charge black hole, and we give a crude catalog of the microstates of the two and three-charge black holes in terms of operators in the dual conformal field theory.
Inflationary dilaton-axion magnetogenesis
Cheng, Shu-Lin; Ng, Kin-Wang
2014-01-01
We discuss the generation of primordial magnetic fields during inflation in the dilaton-axion electromagnetism, in which the dilaton and axion dynamics are introduced in terms of two time dependent functions of the cosmic scale factor, $I(a) F^2/4$ and $J(a) F\\tilde{F}/4$, respectively, where $F$ is the electromagnetic field strength and $\\tilde{F}$ is its dual. We study the form of $J(a)$ that can generate a large seed magnetic field in the weak coupling regime, $I(a)<1$. Although the $J(a)$ function is model dependent, the axion-photon coupling indeed opens up a new window for a successful inflationary magnetogenesis.
Dilatons for Dense Hadronic Matter
Lee, Hyun Kyu
2009-01-01
The idea that the explicit breaking of scale invariance by the trace anomaly of QCD can be rephrased as a spontaneous breaking has been recently exploited to capture the low-energy strong interaction dynamics of dense (and also hot) matter in terms of two dilaton fields, the "soft" (chi_s) and the "hard" (chi_h) fields, in the frame work of the hidden local gauge symmetry. In the Freund-Nambu model, the spontaneous symmetry breaking of scale symmetry is induced by an explicitly breaking term, while the spontaneous symmetry breaking is possible in the flat potential model which is scale symmetric. We discuss the interplay of the soft and hard dilatons using the spontaneously broken scale symmetry schemes and uncover a novel structure of dense matter hitherto unexplored.
Hairy black holes and the endpoint of AdS$_4$ charged superradiance
Dias, Oscar J C
2016-01-01
We construct hairy black hole solutions that merge with the anti-de Sitter (AdS$_4$) Reissner-Nordstr\\"om black hole at the onset of superradiance. These hairy black holes have, for a given mass and charge, higher entropy than the corresponding AdS$_4$-Reissner-Nordstr\\"om black hole. Therefore, they are natural candidates for the endpoint of the charged superradiant instability. On the other hand, hairy black holes never dominate the canonical and grand-canonical ensembles. The zero-horizon radius of the hairy black holes is a soliton (i.e. a boson star under a gauge transformation). We construct our solutions perturbatively, for small mass and charge, so that the properties of hairy black holes can be used to testify and compare with the endpoint of initial value simulations. We further discuss the near-horizon scalar condensation instability which is also present in global AdS$_4$-Reissner-Nordstr\\"om black holes. We highlight the different nature of the near-horizon and superradiant instabilities and that...
P -V criticality of logarithm-corrected dyonic charged AdS black holes
Sadeghi, J.; Pourhassan, B.; Rostami, M.
2016-09-01
In this paper, we consider a dyonic charged anti-de Sitter black hole, which is a holographic dual of a van der Waals fluid. We use logarithm-corrected entropy and study thermodynamics of the black hole and show that holographic picture is still valid. Critical behaviors and stability are also discussed. Logarithmic corrections arises due to thermal fluctuations, which are important when the size of black hole is small. So, thermal fluctuations are interpreted as a quantum effect. It means that we can see the quantum effect of a black hole, which is a gravitational system.
Quantum electron levels in the field of a charged black hole
Energy Technology Data Exchange (ETDEWEB)
Dokuchaev, V. I.; Eroshenko, Yu. N., E-mail: eroshenko@ms2.inr.ac.ru [Institute for Nuclear Research of the Russian Academy of Sciences (Russian Federation)
2015-12-15
Stationary solutions of the Dirac equation in the metric of the charged Reissner–Nordstrom black hole are found. In the case of an extremal black hole, the normalization integral of the wave functions is finite, and the regular stationary solution is physically self-consistent. The presence of quantum electron levels under the Cauchy horizon can have an impact on the final stage of the Hawking evaporation of the black hole, as well as on the particle scattering in the field of the black hole.
Schwinger Effect in (A)dS and Charged Black Hole
Kim, Sang Pyo
2015-01-01
In an (Anti-) de Sitter space and a charged black hole the Schwinger effect is either enhanced by the Hawking radiation or suppressed by the negative curvature. We use the contour integral method to calculate the production of charged pairs in the global (A)dS space. The charge emission from near-extremal black hole is found from the AdS geometry near the horizon and interpreted as the Schwinger effect in a Rindler space with the surface gravity for the acceleration as well as the Schwinger effect in AdS space.
Dilatonic effects near naked singularities
Morris, J R
2011-01-01
Static spherically symmetric solutions of 4d Brans-Dicke theory include a set of naked singularity solutions. Dilatonic effects near the naked singularities result in either a shielding or an antishielding effect from intruding massive test particles. One result is that for a portion of the solution parameter space, no communication between the singularity and a distant observer is possible via massive particle exchanges. Kaluza-Klein gravity is considered as a special case.
Charged Black Hole Solutions in Gauss-Bonnet-Massive Gravity
Hendi, S H; Panah, B Eslam
2015-01-01
Motivated by high interest in the close relation between string theory and black hole solutions, in this paper, we take into account the Einstein-Gauss-Bonnet Lagrangian in the context of massive gravity. We examine the possibility of black hole in this regard, and discuss the types of horizons. Next, we calculate conserved and thermodynamic quantities and check the validity of the first law of thermodynamics. In addition, we investigate the stability of these black holes in context of canonical ensemble. We show that number, type and place of phase transitions points may be significantly affected by the different parameters. Next, by considering cosmological constant as thermodynamical pressure, we will extend phase space and calculate critical values. Then, we construct thermodynamical spacetime by considering mass as thermodynamical potential. We study geometrical thermodynamics of these black holes in context of heat capacity and extended phase space. We show that studying heat capacity, geometrical therm...
Bianchi Type I Cosmologies in Arbitrary Dimensional Dilaton Gravities
Chen, C M; Mak, M K; Chen, Chiang-Mei
2000-01-01
We study the low energy string effective action with an exponential type dilaton potential and vanishing torsion in a Bianchi type I space-time geometry. In the Einstein and string frames the general solution of the gravitational field equations can be expressed in an exact parametric form. Depending on the values of some parameters the obtained cosmological models can be generically divided into three classes, leading to both singular and nonsingular behaviors. The effect of the potential on the time evolution of the mean anisotropy parameter is also considered in detail, and it is shown that a Bianchi type I Universe isotropizes only in the presence of a dilaton field potential or a central deficit charge.
Regular black holes: Electrically charged solutions, Reissner-Nordstr\\"om outside a de Sitter core
Lemos, José P S
2011-01-01
To have the correct picture of a black hole as a whole it is of crucial importance to understand its interior. The singularities that lurk inside the horizon of the usual Kerr-Newman family of black hole solutions signal an endpoint to the physical laws and as such should be substituted in one way or another. A proposal that has been around for sometime, is to replace the singular region of the spacetime by a region containing some form of matter or false vacuum configuration that can also cohabit with the black hole interior. Black holes without singularities are called regular black holes. In the present work regular black hole solutions are found within general relativity coupled to Maxwell's electromagnetism and charged matter. We show that there are objects which correspond to regular charged black holes, whose interior region is de Sitter, whose exterior region is Reissner-Nordstr\\"om, and the boundary between both regions is made of an electrically charged spherically symmetric coat. There are several ...
Energy Technology Data Exchange (ETDEWEB)
Rahaman, Farook; Bhar, Piyali [Jadavpur University, Department of Mathematics, Kolkata, West Bengal (India); Sharma, Ranjan [P. D. Women' s College, Department of Physics, Jalpaiguri (India); Tiwari, Rishi Kumar [Govt. Model Science College, Department of Mathematics, Rewa, MP (India)
2015-03-01
We report a 3-D charged black hole solution in an anti-de Sitter space inspired by noncommutative geometry. In this construction, the black hole exhibits two horizons, which turn into a single horizon in the extreme case. We investigate the impacts of electromagnetic field on the location of the event horizon, mass and thermodynamic properties such as Hawking temperature, entropy, and heat capacity of the black hole. The geodesics of the charged black hole are also analyzed. (orig.)
Prasia, P
2016-01-01
In this work we study the Quasi Normal Modes(QNMs) under massless scalar perturbations and the thermodynamics of linearly charged BTZ black holes in massive gravity in the (Anti)de Sitter((A)dS) space time. It is found that the behavior of QNMs changes with the massive parameter and also with the charge of the black hole. The thermodynamics of such black holes in the (A)dS space time is also analyzed in detail. The behavior of specific heat with temperature for such black holes gives an indication of a phase transition that depends on the massive parameter and also on the charge of the black hole.
Time domain analysis of superradiant instability for the charged stringy black hole–mirror system
Directory of Open Access Journals (Sweden)
Ran Li
2015-11-01
Full Text Available It has been proved that the charged stringy black holes are stable under the perturbations of massive charged scalar fields. However, superradiant instability can be generated by adding the mirror-like boundary condition to the composed system of charged stringy black hole and scalar field. The unstable boxed quasinormal modes have been calculated by using both analytical and numerical methods. In this paper, we further provide a time domain analysis by performing a long time evolution of charged scalar field configuration in the background of the charged stringy black hole with the mirror-like boundary condition imposed. We have used the ingoing Eddington–Finkelstein coordinates to derive the evolution equation, and adopted Pseudo-spectral method and the forth-order Runge–Kutta method to evolve the scalar field with the initial Gaussian wave packet. It is shown by our numerical scheme that Fourier transforming the evolution data coincides well with the unstable modes computed from frequency domain analysis. The existence of the rapid growth mode makes the charged stringy black hole a good test ground to study the nonlinear development of superradiant instability.
Time domain analysis of superradiant instability for the charged stringy black hole-mirror system
Li, Ran; Tian, Yu; Zhang, Hongbao; Zhao, Junkun
2015-11-01
It has been proved that the charged stringy black holes are stable under the perturbations of massive charged scalar fields. However, superradiant instability can be generated by adding the mirror-like boundary condition to the composed system of charged stringy black hole and scalar field. The unstable boxed quasinormal modes have been calculated by using both analytical and numerical methods. In this paper, we further provide a time domain analysis by performing a long time evolution of charged scalar field configuration in the background of the charged stringy black hole with the mirror-like boundary condition imposed. We have used the ingoing Eddington-Finkelstein coordinates to derive the evolution equation, and adopted Pseudo-spectral method and the forth-order Runge-Kutta method to evolve the scalar field with the initial Gaussian wave packet. It is shown by our numerical scheme that Fourier transforming the evolution data coincides well with the unstable modes computed from frequency domain analysis. The existence of the rapid growth mode makes the charged stringy black hole a good test ground to study the nonlinear development of superradiant instability.
Classical resolution of singularities in dilaton cosmologies
Bergshoeff, EA; Collinucci, A; Roest, D; Russo, JG; Townsend, PK
2005-01-01
For models of dilaton gravity with a possible exponential potential, such as the tensor-scalar sector of ITA supergravity, we show how cosmological solutions correspond to trajectories in a 2D Milne space (parametrized by the dilaton and the scale factor). Cosmological singularities correspond to po
Cosmic strings in axionic-dilatonic gravity
Santos, Caroline
2001-05-01
We first consider local cosmic strings in dilaton-axion gravity and show that they are singular solutions. Then we take a supermassive Higgs limit and present expressions for the fields at far distances from the core by applying a Pecci-Quinn and a duality transformation to the dilatonic Melvin's magnetic universe.
Cosmic strings in axionic-dilatonic gravity
Santos, C
2001-01-01
We first consider local cosmic strings in dilaton-axion gravity and show that they are singular solutions. Then we take a supermassive Higgs limit and present expressions for the fields at far distances from the core by applying a Pecci-Quinn and a duality transformation to the dilatonic Melvin's magnetic universe.
Monopole in the dilatonic gauge field theory
Karczewska, D
2000-01-01
A numerical study of coupled to the dilaton field, static, spherically symmetric monopole solutions inspired by the Kaluza-Klein theory with large extra dimensions are presented. The generalized Prasad-Sommerfield solution is obtained. We show that monopole may have also the dilaton cloud configurations.
Charged black hole solutions in Gauss-Bonnet-massive gravity
Hendi, S. H.; Panahiyan, S.; Panah, B. Eslam
2016-01-01
Motivated by high interest in the close relation between string theory and black hole solutions, in this paper, we take into account the Einstein-Gauss-Bonnet Lagrangian in the context of massive gravity. We examine the possibility of black hole in this regard, and discuss the types of horizons. Next, we calculate conserved and thermodynamic quantities and check the validity of the first law of thermodynamics. In addition, we investigate the stability of these black holes in context of canonical ensemble. We show that number, type and place of phase transition points may be significantly affected by different parameters. Next, by considering cosmological constant as thermodynamical pressure, we will extend phase space and calculate critical values. Then, we construct thermodynamical spacetime by considering mass as thermodynamical potential. We study geometrical thermodynamics of these black holes in context of heat capacity and extended phase space. We show that studying heat capacity, geometrical thermodynamics and critical behavior in extended phase space lead to consistent results. Finally, we will employ a new method for obtaining critical values and show that the results of this method are consistent with those of other methods.
Chaotic dynamics of strings in charged black hole backgrounds
Basu, Pallab; Samantray, Prasant
2016-01-01
We study the motion of a string in the background of Reissner-Nordstrom black hole, in both AdS as well as asymptotically flat spacetimes. We describe the phase space of this dynamical system through largest Lyapunov exponent, Poincare sections and basins of attractions. We observe that string motion in these settings is particularly chaotic and comment on its characteristics.
Critical Phenomena in Higher Curvature Charged AdS Black Holes
Directory of Open Access Journals (Sweden)
Arindam Lala
2013-01-01
Full Text Available In this paper, we have studied the critical phenomena in higher curvature charged AdS black holes. We have considered Lovelock-Born-Infeld-AdS black hole as an example. The thermodynamics of the black hole have been studied which reveals the onset of a higher-order phase transition in the black hole in the canonical ensemble (fixed charge ensemble framework. We have analytically derived the critical exponents associated with these thermodynamic quantities. We find that our results fit well with the thermodynamic scaling laws and consistent with the mean field theory approximation. The suggestive values of the other two critical exponents associated with the correlation function and correlation length on the critical surface have been derived.
Conserved Charges and First Law of Thermodynamics for Kerr-de Sitter Black Holes
Hajian, Kamal
2016-01-01
Recently, a general formulation for calculating conserved charges for (black hole) solutions to generally covariant gravitational theories, in any dimensions and with arbitrary asymptotic behaviors has been introduced. Equipped with this method, which can be dubbed as "solution phase space method," we calculate mass and angular momentum for the Kerr-dS black hole. Then, for any choice of horizons, associated entropy and the first law of thermodynamics are derived. Interestingly, according to insensitivity of the analysis to the chosen cosmological constant, the analysis unifies the thermodynamics of rotating stationary black holes in 4 (and other) dimensions with either AdS, flat or dS asymptotics. We extend the analysis to include electric charge, i.e. to the Kerr-Newman-dS black hole.
Magnetically charged regular black hole in a model of nonlinear electrodynamics
Ma, Meng-Sen
2015-01-01
We obtain a magnetically charged regular black hole in general relativity. The source to the Einstein field equations is nonlinear electrodynamic field in a physically reasonable model of nonlinear electrodynamics (NED). "Physically" here means the NED model is constructed on the basis of three conditions: the Maxwell asymptotic in the weak electromagnetic field limit; the presence of vacuum birefringence phenomenon; and satisfying the weak energy condition (WEC). In addition, we analyze the thermodynamic properties of the regular black hole in two ways. According to the usual black hole thermodynamics, we calculate the heat capacity at constant charge, from which we know the smaller black hole is more stable. We also employ the horizon thermodynamics to discuss the thermodynamic quantities, especially the heat capacity at constant pressure.
(Anti-) de Sitter Electrically Charged Black Hole Solutions in Higher-Derivative Gravity
Lin, Kai; Pavan, A B; Abdalla, E
2016-01-01
In this paper, static electrically charged black hole solutions with cosmological constant are investigated in an Einstein-Hilbert theory of gravity with additional quadratic curvature terms. Beside the analytic Schwarzschild (Anti-) de Sitter solutions, non-Schwarzschild (Anti-) de Sitter solutions are also obtained numerically by employing the shooting method. The results show that there exist two groups of asymptotically (Anti-) de Sitter spacetimes for both charged and uncharged black holes. In particular, it was found that for uncharged black holes the first group can be reduced to the Schwarzschild (Anti-) de Sitter solution, while the second group is intrinsically different from a Schwarzschild (Anti-) de Sitter solution even when the charge and the cosmological constant become zero.
Tunnelling Radiation of Charged and Magnetized Massive Particles from BTZ Black Holes
Institute of Scientific and Technical Information of China (English)
HE Tang-Mei; ZHANG Jing-Yi
2007-01-01
We investigate the tunnelling radiation of charged and magnetized massive particles from a Ba(n)ados-TeitelboimZanelli (BTZ) black hole by extending the Parikh-Wilczek tunnelling framework. In order to calculate the emission rate,we reconstruct the electromagnetic field tensor and the Lagrangian of the field corresponding to the source with electric and magnetic charges,and treat the charges as an equivalent electric charge for simplicity in the later calculation.The result supports Parikh-Wilczek's conclusion,that is,the Hawking thermal radiation actually deviates from perfect thermality and agrees with an underlying unitary theory.
Hawking radiation from the charged and magnetized BTZ black hole via covariant anomaly
Institute of Scientific and Technical Information of China (English)
Zeng Xiao-Xiong; Yang Shu-Zheng
2009-01-01
This paper discusses Hawking radiation from the charged and magnetized Bafiados-Teitelboim-Zanelli (BTZ) black hole from the viewpoint of anomaly, initiated by Robinson and Wilczek recently. It reconstructs the electromagnetic field tensor and the Lagrangian of the field corresponding to the source with electric and magnetic charges to redefine an equivalent charge and gauge potential. It employs the covariant anomaly cancellation method to determine thecompensating fluxes of charge flow and energy-momentum tensor, which are shown to match with those of the 2- dimensional blackbody radiation at the Hawking temperature exactly.
On Thermodynamical Relation Between Rotating Charged BTZ Black Holes and Effective String Theory
Institute of Scientific and Technical Information of China (English)
Alexis Larra(~n)aga
2008-01-01
In this paper we study the first law of thermodynamics for the (2+1)-dimensional rotating charged BTZ black hole considering a pair of thermodynamical systems constructed with the two horizons of this solution. We show that these two systems are similar to the right and left movers of string theory and that the temperature associated with the black hole is the harmonic mean of the temperatures associated with these two systems.
Azreg-Aïnou, Mustapha
2012-01-01
Properties pertaining to thermodynamical local stability of Reissner-Nordstr\\"om black holes surrounded by quintessence as well as adiabatic invariance, adiabatic charging and a generalized Smarr formula are discussed. Limits for the entropy, temperature and electric potential ensuring stability of canonical ensembles are determined by the classical thermodynamical and Poincar\\'e methods. By the latter approach we show that microcanonical ensembles (isolated black holes) are stable. Two geometrical approaches lead to determine the same states corresponding to second order phase transitions.
Universal area product formulas for rotating and charged black holes in four and higher dimensions.
Cvetič, M; Gibbons, G W; Pope, C N
2011-03-25
We present explicit results for the product of all horizon areas for general rotating multicharge black holes, both in asymptotically flat and asymptotically anti-de Sitter spacetimes in four and higher dimensions. The expressions are universal, and depend only on the quantized charges, quantized angular momenta and the cosmological constant. If the latter is also quantized these universal results may provide a "looking glass" for probing the microscopics of general black holes.
Effect of scalar field mass on gravitating charged scalar solitons and black holes in a cavity
Ponglertsakul, Supakchai
2016-01-01
We study soliton and black hole solutions of Einstein charged scalar field theory in cavity. We examine the effect of introducing a scalar field mass on static, spherically symmetric solutions of the field equations. We focus particularly on the spaces of soliton and black hole solutions, as well as studying their stability under linear, spherically symmetric perturbations of the metric, electromagnetic field, and scalar field.
Effect of scalar field mass on gravitating charged scalar solitons and black holes in a cavity
Ponglertsakul, Supakchai; Winstanley, Elizabeth
2017-01-01
We study soliton and black hole solutions of Einstein charged scalar field theory in cavity. We examine the effect of introducing a scalar field mass on static, spherically symmetric solutions of the field equations. We focus particularly on the spaces of soliton and black hole solutions, as well as studying their stability under linear, spherically symmetric perturbations of the metric, electromagnetic field, and scalar field.
Black hole Area-Angular momentum-Charge inequality in dynamical non-vacuum spacetimes
Clément, María E Gabach
2011-01-01
We show that the area-angular momentum-charge inequality (A/(4\\pi))^2 \\geq (2J)^2 + (Q_E^2 + Q_M^2)^2 holds for apparent horizons of electrically and magnetically charged rotating black holes in generic dynamical and non-vacuum spacetimes. More specifically, this quasi-local inequality applies to axially symmetric closed outermost stably marginally (outer) trapped surfaces, embedded in non-necessarily axisymmetric black hole spacetimes with non-negative cosmological constant and matter content satisfying the dominant energy condition.
Three-dimensional SCFT on conic space as hologram of charged topological black hole
Energy Technology Data Exchange (ETDEWEB)
Huang, Xing [School of Physics & Astronomy and Center for Theoretical Physics,Seoul National University, Seoul 151-747 (Korea, Republic of); Rey, Soo-Jong [School of Physics & Astronomy and Center for Theoretical Physics, Seoul National University, Seoul 151-747 (Korea, Republic of); Center for Quantum Space-Time, Sogang University,Seoul 121-742 (Korea, Republic of); Zhou, Yang [Center for Quantum Space-Time, Sogang University, Seoul 121-742 (Korea, Republic of)
2014-03-26
We construct three-dimensional N=2 supersymmetric field theories on conic spaces. Built upon the fact that the partition function depends solely on the Reeb vector of the Killing vector, we propose that holographic dual of these theories are four-dimensional, supersymmetric charged topological black holes. With the supersymmetry localization technique, we study conserved supercharges, free energy, and supersymmetric Rényi entropy. At planar large N limit, we demonstrate perfect agreement between the superconformal field theories and the supersymmetric charged topological black holes.
Huang, Xing; Zhou, Yang
2014-01-01
We construct three-dimensional N=2 supersymmetric conformal field theories on conic spaces. Built upon the fact that the partition function depends solely on the Reeb vector of the Killing vector, we propose that holographic dual of these theories are four-dimensional, supersymmetric charged topological black holes. With the supersymmetry localization technique, we study conserved supercharges, free energy, and Renyi entropy. At planar large N limit, we demonstrate perfect agreement between the superconformal field theories and the supersymmetric charged topological black holes.
A perspective on Black Hole Horizons from the Quantum Charged Particle
Jaramillo, José Luis
2016-01-01
Black hole apparent horizons possess a natural notion of stability, whose spectral characterization can be related to the problem of the stationary quantum charged particle. Such mathematical relation leads to an "analyticity conjecture" on the dependence of the spectral properties on a complex "fine-structure-constant" parameter, that can reduce the study of the spectrum of the (non-selfadjoint) MOTS-stability operator to that of the (selfadjoint) Hamiltonian of the quantum charged particle. Moreover, this perspective might open an avenue to the spinorial treatment of apparent horizon (MOTS-)stability and to the introduction of semiclassical tools to explore some of the qualitative aspects of this black hole spectral problem.
Tunneling of massive and charged particles from noncommutative Reissner-Nordstr\\"{o}m black hole
Nozari, Kourosh
2012-01-01
Massive charged and uncharged particles tunneling from commutative Reissner-Nordstrom black hole horizon has been studied with details in literature. Here, by adopting the coherent state picture of spacetime noncommutativity, we study tunneling of massive and charged particles from a noncommutative inspired Reissner-Nordstrom black hole horizon. We show that Hawking radiation in this case is not purely thermal and there are correlations between emitted modes. These correlations may provide a solution to the information loss problem. We also study thermodynamics of noncommutative horizon in this setup.
Institute of Scientific and Technical Information of China (English)
YANG Shu-Zheng; CHEN De-You
2007-01-01
@@ Taking the self-gravitation interaction and energy conservation, charge conservation and angular momentum conservation into account, we discuss the tunnelling characteristics of the charged particle from Sen black hole by the Hamilton-Jacobi method. The result shows that the tunnelling probability is related to the change of Bekenstein-Hawking entropy, and the actual radiation spectrum deviates from the pure thermal one, which is consistent with the result of Parikh and Wilczek and gives a new method to correct the Hawking pure thermal spectrum of Sen black hole.
Transitions in Dilaton Holography with Global or Local Symmetries
Salvio, Alberto
2013-01-01
We study various transitions in dilaton holography, including those associated with the spontaneous breaking of a global (superfluid case) or local (superconductor case) U(1) symmetry in diverse dimensions d. By analyzing the thermodynamics of the dilaton-gravity system we find that scale invariance is broken at low temperatures, as shown by a nontrivial hyperscaling violation exponent in the infrared; increasing the temperature we recover scale symmetry in a d dependent way: while for d=2+1 a phase transition is found, for d=3+1 the transition is rather a crossover (as expected in QCD). When the U(1) is preserved and at low temperatures, the system is insulating for arbitrary d if the dilaton is appropriately coupled to the gauge field; for other couplings we also find a linear in temperature resistivity. We then determine the prediction of these models for several quantities in the superconducting phase: the DC and AC conductivity, the gap for charged excitations, the superfluid density, the vortex profiles...
Chaotic dynamics of strings in charged black hole backgrounds
Basu, Pallab; Chaturvedi, Pankaj; Samantray, Prasant
2017-03-01
We study the motion of a string in the background of a Reissner-Nordstrom black hole, in both anti-de Sitter as well as asymptotically flat spacetimes. We describe the phase space of this dynamical system through the largest Lyapunov exponent, Poincaré sections and basins of attraction. We observe that string motion in these settings is particularly chaotic and comment on its characteristics.
Charged isotropic non-Abelian dyonic black branes
Directory of Open Access Journals (Sweden)
Yves Brihaye
2015-05-01
Full Text Available We construct black holes with a Ricci-flat horizon in Einstein–Yang–Mills theory with a negative cosmological constant, which approach asymptotically an AdSd spacetime background (with d≥4. These solutions are isotropic, i.e. all space directions in a hypersurface of constant radial and time coordinates are equivalent, and possess both electric and magnetic fields. We find that the basic properties of the non-Abelian solutions are similar to those of the dyonic isotropic branes in Einstein–Maxwell theory (which, however, exist in even spacetime dimensions only. These black branes possess a nonzero magnetic field strength on the flat boundary metric, which leads to a divergent mass of these solutions, as defined in the usual way. However, a different picture is found for odd spacetime dimensions, where a non-Abelian Chern–Simons term can be incorporated in the action. This allows for black brane solutions with a magnetic field which vanishes asymptotically.
Entropy of a rotating and charged black string to all orders in the Planck length
Institute of Scientific and Technical Information of China (English)
Zhao Ren; Wu Yue-Qin; Zhang Li-Chun
2009-01-01
By using the entanglement entropy method, this paper calculates the statistical entropy of the Bose and Fermi fields in thin films, and derives the Bekenstein-Hawking entropy and its correction term on the background of a rotating and charged black string. Here, the quantum field is entangled with quantum states in the black string and thin film to the event horizon from outside the rotating and charged black string. Taking into account the effect of the generalized uncertainty principle on quantum state density, it removes the difficulty of the divergence of state density near the event horizon in the brick-wall model. These calculations and discussions imply that high density quantum states near the event horizon of a black string are strongly correlated with the quantum states in a black string and that black string entropy is a quantum effect. The ultraviolet cut-off in the brick-wall model is not reasonable. The generalized uncertainty principle should be considered in the high energy quantum field near the event horizon. From the viewpoint of quantum statistical mechanics, the correction value of Bekenstein-Hawking entropy is obtained. This allows the fundamental recognition of the correction value of black string entropy at nonspherical coordinates.
The charged black-hole bomb: A lower bound on the charge-to-mass ratio of the explosive scalar field
Directory of Open Access Journals (Sweden)
Shahar Hod
2016-04-01
Full Text Available The well-known superradiant amplification mechanism allows a charged scalar field of proper mass μ and electric charge q to extract the Coulomb energy of a charged Reissner–Nordström black hole. The rate of energy extraction can grow exponentially in time if the system is placed inside a reflecting cavity which prevents the charged scalar field from escaping to infinity. This composed black-hole-charged-scalar-field-mirror system is known as the charged black-hole bomb. Previous numerical studies of this composed physical system have shown that, in the linearized regime, the inequality q/μ>1 provides a necessary condition for the development of the superradiant instability. In the present paper we use analytical techniques to study the instability properties of the charged black-hole bomb in the regime of linearized scalar fields. In particular, we prove that the lower bound qμ>rm/r−−1rm/r+−1 provides a necessary condition for the development of the superradiant instability in this composed physical system (here r± are the horizon radii of the charged Reissner–Nordström black hole and rm is the radius of the confining mirror. This analytically derived lower bound on the superradiant instability regime of the composed black-hole-charged-scalar-field-mirror system is shown to agree with direct numerical computations of the instability spectrum.
On uniqueness of charged Kerr-AdS black holes in five dimensions
Madden, O; Madden, Owen; Ross, Simon F.
2004-01-01
We show that the solutions describing charged rotating black holes in five-dimensional gauged supergravities found recently by Cvetic, Lu and Pope [hep-th/0406196,hep-th/0407058] are completely specified by the mass, charges and angular momentum. The additional parameter appearing in these solutions is removed by a coordinate transformation and redefinition of parameters. Thus, the apparent hair in these solutions is unphysical.
Solitons of axion-dilaton gravity
Bakas, Ioannis
1996-01-01
We use soliton techniques of the two-dimensional reduced beta-function equations to obtain non-trivial string backgrounds from flat space. These solutions are characterized by two integers (n, m) referring to the soliton numbers of the metric and axion-dilaton sectors respectively. We show that the Nappi-Witten universe associated with the SL(2) x SU(2) / SO(1, 1) x U(1) CFT coset arises as an (1, 1) soliton in this fashion for certain values of the moduli parameters, while for other values of the soliton moduli we arrive at the SL(2)/SO(1, 1) x SO(1, 1)^2 background. Ordinary 4-dim black-holes arise as 2-dim (2, 0) solitons, while the Euclidean worm-hole background is described as a (0, 2) soliton on flat space. The soliton transformations correspond to specific elements of the string Geroch group. These could be used as starting point for exploring the role of U-dualities in string compactifications to two dimensions.
Electrically charged black hole solutions in generalized gauge field theories
Energy Technology Data Exchange (ETDEWEB)
Diaz-Alonso, J; Rubiera-Garcia, D, E-mail: joaquin.diaz@obspm.fr, E-mail: diego.rubiera-garcia@obspm.fr [LUTH, Observatoire de Paris, CNRS, Universite Paris Diderot. 5 Place Jules Janssen, 92190 Meudon (France); Departamento de Fisica, Universidad de Oviedo. Avda. Calvo Sotelo 18, 33007 Oviedo, Asturias (Spain)
2011-09-22
We summarize the main features of a class of anomalous (asymptotically flat, but non Schwarzschild-like) gravitational configurations in models of gravitating non-linear electrodynamics (G-NED) whose Lagrangian densities are defined as arbitrary functions of the two field invariants and constrained by several physical admissibility conditions. This class of models and their associated electrostatic spherically symmetric black hole (ESSBH) solutions are characterized by the behaviours of the Lagrangian densities around the vacuum and at the boundary of their domain of definition.
New Charged Black Holes with Conformal Scalar Hair
Anabalon, Andres
2009-01-01
A general class of four dimensional, stationary solutions of the Einstein-Maxwell system with a conformally coupled scalar field is constructed in this paper. The stationary case is presented and shown to belong to the Plebanski-Demianski family which implies that the static metric has the form of the C-metric. It is shown that in the static, AdS case, a new family of Black Holes arises. They turn out to be cohomogeneity two, with horizons that are not Einstein neither homogenous manifolds. The usual conical singularities present in the C-metric are automatically removed from the spacetime due to the backreaction of the scalar field. The scalar field carries a continuous parameter that resembles the usual acceleration present in the C-metric. When this parameter vanishes the static family it is shown to contain either to the dyonic Bocharova-Bronnikov-Melnikov-Bekenstein solution or the dyonic extension of the Martinez-Troncoso-Zanelli black holes, depending on the value of the cosmological constant.
Entropy bound of horizons for accelerating, rotating and charged Plebanski-Demianski black hole
Debnath, Ujjal
2016-09-01
We first review the accelerating, rotating and charged Plebanski-Demianski (PD) black hole, which includes the Kerr-Newman rotating black hole and the Taub-NUT spacetime. The main feature of this black hole is that it has 4 horizons like event horizon, Cauchy horizon and two accelerating horizons. In the non-extremal case, the surface area, entropy, surface gravity, temperature, angular velocity, Komar energy and irreducible mass on the event horizon and Cauchy horizon are presented for PD black hole. The entropy product, temperature product, Komar energy product and irreducible mass product have been found for event horizon and Cauchy horizon. Also their sums are found for both horizons. All these relations are dependent on the mass of the PD black hole and other parameters. So all the products are not universal for PD black hole. The entropy and area bounds for two horizons have been investigated. Also we found the Christodoulou-Ruffini mass for extremal PD black hole. Finally, using first law of thermodynamics, we also found the Smarr relation for PD black hole.
Proof of the area-angular momentum-charge inequality for axisymmetric black holes
Clement, María E Gabach; Reiris, Martín
2012-01-01
We give a comprehensive discussion, including a detailed proof, of the area-angular momentum-charge inequality for axisymmetric black holes. We analyze the inequality from several viewpoints, in particular including aspects with a theoretical interest well beyond the Einstein-Maxwell theory.
The Central Charge of the Warped AdS^3 Black Hole
Gupta, Kumar S; Sen, Siddhartha; Sivakumar, M
2010-01-01
The AdS/CFT conjecture offers the possibility of a quantum description for a black hole in terms of a CFT. This has ledto the study of general AdS^3 type black holes with a view to constructing an explicit toy quantum black hole model. Such a CFT description would be characterized by its central charge and the dimensions of its primary fields. Recently the expression for the central charges (C_L, C_R) of the CFT dual to the warped AdS^3 have been determined using asymptotic symmetry arguments. The central charges depend, as expected, on the warping factor. We show that topological arguments, used by Witten to constrain central charges for the BTZ black hole, can be generalized to deal with the warped AdS^3 case. Topology constrains the warped factor to be rational numbers while quasinormal modes are conjectured to give the dimensions of primary fields. We find that in the limit when warping is large or when it takes special rational values the system tends to Witten's conjectured unique CFT's with central cha...
On the universality of thermodynamics and $\\eta/s$ ratio for the charged Lovelock black branes
Cadoni, Mariano; Tuveri, Matteo
2016-01-01
We investigate general features of charged Lovelock black branes by giving a detailed description of geometrical, thermodynamic and holographic properties of charged Gauss-Bonnet (GB) black branes in five dimensions. We show that when expressed in terms of effective physical parameters, the thermodynamic behaviour of charged GB black branes is completely indistinguishable from that of charged Einstein black branes. Moreover, the extremal, near-horizon limit of the two classes of branes is exactly the same as they allow for the same AdS$_2\\times R_3$, near-horizon, exact solution. This implies that, although in the UV the associated dual QFTs are different, they flow in the IR to the same fixed point. The calculation of the shear viscosity to entropy ratio $\\eta/s$ confirms these results. Despite the GB dual plasma has in general a non-universal temperature-dependent $\\eta/s$, it flows monotonically to the universal value $1/4\\pi$ in the IR. For negative (positive) GB coupling constant, $\\eta/s$ is an increasi...
Quantum tunneling from the charged non-rotating BTZ black hole with GUP
Sadeghi, Jafar; Reza Shajiee, Vahid
2017-03-01
In the present paper, the quantum corrections to the temperature, entropy and specific heat capacity of the charged non-rotating BTZ black hole are studied by the generalized uncertainty principle in the tunneling formalism. It is shown that quantum corrected entropy would be of the form of predicted entropy in quantum gravity theories like string theory and loop quantum gravity.
BPS-like bound and thermodynamics of the charged BTZ black hole
Cadoni, M
2009-01-01
The charged Banados-Teitelboim-Zanelli (BTZ) black hole is plagued by several pathologies: a) Presence of divergent boundary terms in the action, hence of a divergent black hole mass; b) Once a finite, renormalized, mass M is defined black hole states exist for arbitrarily negative values of M; c) There is no upper bound on the charge Q. We show that these pathological features are an artifact of the renormalization procedure. They can be completely removed by using an alternative renormalization scheme leading to a different definition M_0 of the black hole mass, which is the total energy inside the horizon. The new mass satisfies a BPS-like bound M_0\\ge (\\pi/2)Q^2 and the heat capacity of the hole is positive. We also discuss the black hole thermodynamics that arises when M_0 is interpreted as the internal energy of the system. We show, using three independent approaches (black hole thermodynamics, Einstein equations, Euclidean action formulation) that M_0 satisfies the first law if a term describing the me...
BPS-like bound and thermodynamics of the charged BTZ black hole
Cadoni, Mariano; Monni, Cristina
2009-07-01
The charged Bañados-Teitelboim-Zanelli (BTZ) black hole is plagued by several pathologies: (a) Divergent boundary terms are present in the action; hence, we have a divergent black-hole mass. (b) Once a finite, renormalized, mass M is defined, black-hole states exist for arbitrarily negative values of M. (c) There is no upper bound on the charge Q. We show that these pathological features are an artifact of the renormalization procedure. They can be completely removed by using an alternative renormalization scheme leading to a different definition M0 of the black-hole mass, which is the total energy inside the horizon. The new mass satisfies a BPS-like bound M0≥(π)/(2)Q2, and the heat capacity of the hole is positive. We also discuss the black-hole thermodynamics that arises when M0 is interpreted as the internal energy of the system. We show, using three independent approaches (black-hole thermodynamics, Einstein equations, and Euclidean action formulation), that M0 satisfies the first law if a term describing the mechanical work done by the electrostatic pressure is introduced.
Phase transition in extended thermodynamic phase space and charged Horava-Lifshitz black holes
Poshteh, Mohammad Bagher Jahani
2016-01-01
For charged black holes in Horava-Lifshitz gravity, it is shown that a second order phase transition takes place in extended phase space. We study the behavior of specific heat and free energy at the point of transition in canonical and grand canonical ensembles and show that the black hole falls into a state which is locally and globally stable. We relate the second order nature of phase transition to the fact that the phase transition occurs at a sharp temperature and not over a temperature interval. By taking cosmological constant as thermodynamic pressure for charged black holes, we extend Ehrenfest's equations. We obtain nine equations and show that, all of them are satisfied at the point in which the specific heat diverges. We also apply geometrothermodynamics to extended phase space and show that the scalar curvature of Quevedo metric diverges at the point at which the second order phase transition takes place.
Hawking Radiation of the Charged Particle via Tunneling from the Kaluza-Klein Black Hole
Pu, Jin; Han, Yan
2016-08-01
In this paper, by applying the Lagrangian analysis on the action, we first redefine the geodesic equation of the charged massive particle. Then, basing on the new definition of the geodesic equation, we revisit the Hawking radiation of the charged massive particle via tunneling from the event horizon of the Kaluza-Klein black hole. In our treatment, the geodesic equation of the charged massive particle is defined uniformly with that of the massless particle, which overcomes the shortcomings of its previous definition, and is more suitable for the tunneling mechanism. The highlight of our work is a new and important development for the Parikh-Wilczek's tunneling method.
Hawking Radiation of the Charged Particle via Tunneling from the Kaluza-Klein Black Hole
Pu, Jin; Han, Yan
2016-12-01
In this paper, by applying the Lagrangian analysis on the action, we first redefine the geodesic equation of the charged massive particle. Then, basing on the new definition of the geodesic equation, we revisit the Hawking radiation of the charged massive particle via tunneling from the event horizon of the Kaluza-Klein black hole. In our treatment, the geodesic equation of the charged massive particle is defined uniformly with that of the massless particle, which overcomes the shortcomings of its previous definition, and is more suitable for the tunneling mechanism. The highlight of our work is a new and important development for the Parikh-Wilczek's tunneling method.
Moller's Energy in the Dyadosphere of a Charged Black Hole
Aydogdu, O; Aydogdu, Oktay; Salti, Mustafa
2006-01-01
We use the M{\\o}ller energy-momentum complex both in general relativity and teleparallel gravity to evaluate energy distribution (due to matter plus fields including gravity) in the dyadosphere region for Reissner-Nordstr{\\"o}m black hole. We found the same and acceptable energy distribution in these different approaches of the M{\\o}ller energy-momentum complex. Our teleparallel gravitational result is also independent of the teleparallel dimensionless coupling constant, which means that it is valid in any teleparallel model. This paper sustains (a) the importance of the energy-momentum definitions in the evaluation of the energy distribution of a given space-time and (b) the viewpoint of Lessner that the M{\\o}ller energy-momentum complex is a powerful concept for energy and momentum.
Time domain analysis of superradiant instability for the charged stringy black hole-mirror system
Li, Ran; Zhang, Hongbao; Zhao, Junkun
2015-01-01
It has been proved that the charged stringy black holes are stable under the perturbations of massive charged scalar fields. However, superradiant instability can be generated by adding the mirror-like boundary condition to the composed system of charged stringy black hole and scalar field. The unstable boxed quasinormal modes have been calculated by using both analytical and numerical method. In this paper, we further provide a time domain analysis by performing a long time evolution of charged scalar field configuration in the background of the charged stringy black hole with the mirror-like boundary condition imposed. We have used the ingoing Eddington-Finkelstein coordinates to derive the evolution equation, and adopted Pseudo-spectral method and the forth-order Runge-Kutta method to evolve the scalar field with the initial Gaussian wave packet. It is shown by our numerical scheme that Fourier transforming the evolution data coincides well with the unstable modes computed from frequency domain analysis. T...
Universal charge-mass relation: From black holes to atomic nuclei
Energy Technology Data Exchange (ETDEWEB)
Hod, Shahar, E-mail: shaharhod@gmail.co [The Ruppin Academic Center, Emeq Hefer 40250 (Israel); The Hadassah Institute, Jerusalem 91010 (Israel)
2010-10-04
The cosmic censorship hypothesis, introduced by Penrose forty years ago, is one of the corner stones of general relativity. This conjecture asserts that spacetime singularities that arise in gravitational collapse are always hidden inside of black holes. The elimination of a black-hole horizon is ruled out by this principle because that would expose naked singularities to distant observers. We test the consistency of this prediction in a gedanken experiment in which a charged object is swallowed by a charged black hole. We find that the validity of the cosmic censorship conjecture requires the existence of a charge-mass bound of the form q{<=}{mu}{sup 2/3}E{sub c}{sup -1/3}, where q and {mu} are the charge and mass of the physical system respectively, and E{sub c} is the critical electric field for pair-production. Applying this bound to charged atomic nuclei, one finds an upper limit on the number Z of protons in a nucleus of given mass number A: Z{<=}Z{sup *}={alpha}{sup -1/3}A{sup 2/3}, where {alpha}=e{sup 2}/h is the fine structure constant. We test the validity of this novel bound against the (Z,A)-relation of atomic nuclei as deduced from the Weizsaecker semi-empirical mass formula.
NUT-charged black holes in matter-coupled N=2, D=4 gauged supergravity
Colleoni, Marta; Klemm, Dietmar
2012-06-01
Using the results of Cacciatori, Klemm, Mansi, and Zorzan [J. High Energy Phys.JHEPFG1029-8479 05 (2008) 09710.1088/1126-6708/2008/05/097], where all timelike supersymmetric backgrounds of N=2, D=4 matter-coupled supergravity with Fayet-Iliopoulos gauging were classified, we construct genuine NUT-charged BPS black holes in anti-deSitter4 with nonconstant moduli. The calculations are exemplified for the SU(1,1)/U(1) model with prepotential F=-iX0X1. The resulting supersymmetric black holes have a hyperbolic horizon and carry two electric, two magnetic, and one NUT charge, which are however not all independent, but are given in terms of three free parameters. We find that turning on a NUT charge lifts the flat directions in the effective black hole potential, such that the horizon values of the scalars are completely fixed by the charges. We also oxidize the solutions to 11 dimensions, and find that they generalize the geometry found in the work of Gauntlett, Kim, Pakis, and Waldram [Phys. Rev. DPRVDAQ0556-2821 65, 026003 (2001)10.1103/PhysRevD.65.026003] corresponding to membranes wrapping holomorphic curves in a Calabi-Yau fivefold. Finally, a class of NUT-charged Nernst branes is constructed as well, but these have curvature singularities at the horizon.
Entropy Bound of Horizons for Accelerating, Rotating and Charged Plebanski-Demianski Black Hole
Debnath, Ujjal
2015-01-01
We first review the accelerating, rotating and charged Plebanski-Demianski (PD) black hole, which includes the Kerr-Newman rotating black hole and the Taub-NUT spacetime. The main feature of this black hole is that it has 4 horizons like event horizon, Cauchy horizon and two accelerating horizons. In the non-extremal case, the surface area, entropy, surface gravity, temperature, angular velocity, Komar energy and irreducible mass on the event horizon and Cauchy horizon are presented for PD black hole. The entropy product, temperature product, Komar energy product and irreducible mass product are found for event horizon and Cauchy horizon. Also their sums are also found for both horizons. All these relations are found to be depend on mass of the PD black hole and other parameters. So all the products are not universal for PD black hole. The entropy and area bounds for two horizons are investigated. Also we found the Christodoulou-Ruffini mass for extremal PD black hole. Finally, using first law of thermodynami...
Gravitating BPS dyons witout a dilaton
Lee, C; Lee, Choonkyu; Park, Q Han
1996-01-01
We describe curved-space BPS dyon solutions, the ADM mass of which saturates the gravitational version of the Bogomol'nyi bound. This generalizes self-gravitating BPS monopole solutions of Gibbons et al. when there is no dilaton.
Neutrino-axion-dilaton interconnection
Bertolini, Stefano; Kolešová, Helena; Malinský, Michal; Vasquez, Juan Carlos
2016-01-01
We show that a recently proposed framework that provides a simple connection between Majorana neutrinos and an invisible axion in minimal scalar extensions of the standard electroweak model can be naturally embedded in a classically scale-invariant setup. The explicit breaking of the scale invariance \\`a la Coleman-Weinberg generates the Peccei-Quinn and electroweak scales. The spontaneous breaking of the chiral $U(1)_{PQ}$ triggers the generation of neutrino masses via Type-II seesaw and, at the same time, provides a dynamical solution to the strong CP problem as well as the axion as a dark matter candidate. The electroweak and neutrino mass scales are obtained via a technically natural ultraweak limit of the singlet scalar interactions. Accordingly, a realistic and perturbatively stable scalar spectrum, possibly in the reach of the LHC, is naturally obtained. A very light pseudo-dilaton characterizes such a setting. The vacuum stability of the extended setup is discussed.
Van der Waals-like behaviour of charged black holes and hysteresis in the dual QFTs
Directory of Open Access Journals (Sweden)
Mariano Cadoni
2017-05-01
Full Text Available Using the rules of the AdS/CFT correspondence, we compute the spherical analogue of the shear viscosity, defined in terms of the retarded Green function for the stress-energy tensor for QFTs dual to five-dimensional charged black holes of general relativity with a negative cosmological constant. We show that the ratio between this quantity and the entropy density, η˜/s, exhibits a temperature-dependent hysteresis. We argue that this hysteretic behaviour can be explained by the Van der Waals-like character of charged black holes, considered as thermodynamical systems. Under the critical charge, hysteresis emerges owing to the presence of two stable states (small and large black holes connected by a meta-stable region (intermediate black holes. A potential barrier prevents the equilibrium path between the two stable states; the system evolution must occur through the meta-stable region, and a path-dependence of η˜/s is generated.
Critical phenomena in higher curvature charged AdS black holes
Lala, Arindam
2012-01-01
In this paper we have studied the critical phenomena in higher curvature charged black holes in the anti-de Sitter (AdS) space-time. As an example we have considered the third order Lovelock-Born-Infeld black holes in AdS space-time. We have analytically derived the thermodynamic quantities of the system. Our analysis revealed the onset of a higher order phase transition in the black hole leading to an infinite discontinuity in the specific heat at constant charge at the critical points. Our entire analysis is based on the canonical framework where we have fixed the charge of the black hole. In an attempt to study the behavior of the thermodynamic quantities near the critical points we have derived the critical exponents of the system explicitly. Although the values of the critical points have been determined numerically, the critical exponents are calculated analytically. Our results fit well with the thermodynamic scaling laws. The scaling hypothesis is also seen to be consistent with these scaling laws. We...
Thermodynamics of charged black holes in Einstein-Horndeski-Maxwell theory
Feng, Xing-Hui; Liu, Hai-Shan; Lü, H.; Pope, C. N.
2016-02-01
We extend an earlier investigation of the thermodynamics of static black holes in an Einstein-Horndeski theory of gravity coupled to a scalar field, by including now an electromagnetic field as well. By studying the two-parameter families of charged static black holes, we obtain much more powerful constraints on the thermodynamics since, unlike in the uncharged one-parameter case, now the right-hand side of the first law is not automatically integrable. In fact, this allows us to demonstrate that there must be an additional contribution in the first law, over and above the usual terms expected for charged black holes. The origin of the extra contribution can be attributed to the behavior of the scalar field on the horizon of the black hole. We carry out the calculations in four dimensions and also in general dimensions. We also derive the ratio of viscosity to entropy for the dual boundary field theory, showing that the usual viscosity bound for isotropic solutions can be violated, with the ratio depending on the mass and charge.
Effective field theory of slowly-moving "extreme black holes"
Degura, Yoshitaka; Shiraishi, Kiyoshi
2000-01-01
We consider the non-relativistic effective field theory of ``extreme black holes'' in the Einstein-Maxwell-dilaton theory with an arbitrary dilaton coupling. We investigate finite-temperature behavior of gas of ``extreme black holes'' using the effective theory. The total energy of the classical many-body system is also derived.
Strong subadditivity, null energy condition and charged black holes
Energy Technology Data Exchange (ETDEWEB)
Caceres, Elena [Facultad de Ciencias, Universidad de Colima,Bernal Diaz del Castillo 340, Colima (Mexico); Theory Group, Department of Physics, The University of Texas,Austin, TX 78712 (United States); Kundu, Arnab [Theory Group, Department of Physics, The University of Texas,Austin, TX 78712 (United States); Pedraza, Juan F.; Tangarife, Walter [Theory Group, Department of Physics, The University of Texas,Austin, TX 78712 (United States); Texas Cosmology Center, The University of Texas,Austin, TX 78712 (United States)
2014-01-16
Using the Hubeny-Rangamani-Takayanagi (HRT) conjectured formula for entanglement entropy in the context of the AdS/CFT correspondence with time-dependent backgrounds, we investigate the relation between the bulk null energy condition (NEC) of the stress-energy tensor with the strong sub-additivity (SSA) property of entanglement entropy in the boundary theory. In a background that interpolates between an AdS to an AdS-Reissner-Nordstrom-type geometry, we find that generically there always exists a critical surface beyond which the violation of NEC would naively occur. However, the extremal area surfaces that determine the entanglement entropy for the boundary theory, can penetrate into this forbidden region only for certain choices for the mass and the charge functions in the background. This penetration is then perceived as the violation of SSA in the boundary theory. We also find that this happens only when the critical surface lies above the apparent horizon, but not otherwise. We conjecture that SSA, which is thus non-trivially related to NEC, also characterizes the entire time-evolution process along which the dual field theory may thermalize.
Strong Subadditivity, Null Energy Condition and Charged Black Holes
Caceres, Elena; Pedraza, Juan F; Tangarife, Walter
2014-01-01
Using the Hubeny-Rangamani-Takayanagi (HRT) conjectured formula for entanglement entropy in the context of the AdS/CFT correspondence with time-dependent backgrounds, we investigate the relation between the bulk null energy condition (NEC) of the stress-energy tensor with the strong sub-additivity (SSA) property of entanglement entropy in the boundary theory. In a background that interpolates between an AdS to an AdS-Reissner-Nordstrom-type geometry, we find that generically there always exists a critical surface beyond which the violation of NEC would naively occur. However, the extremal area surfaces that determine the entanglement entropy for the boundary theory, can penetrate into this forbidden region only for certain choices for the mass and the charge functions in the background. This penetration is then perceived as the violation of SSA in the boundary theory. We also find that this happens only when the critical surface lies above the apparent horizon, but not otherwise. We conjecture that SSA, which...
Pair Production, Vacuum Polarization and Anomaly in (A)dS and Charged Black Holes
Kim, Sang Pyo
2016-01-01
We explore the connection between the distribution of particles spontaneously produced from an electric field or black hole and the vacuum persistence, twice the imaginary part of the one-loop effective action. Employing the reconstruction conjecture, we find the effective action for the Bose-Einstein or Fermi-Dirac distribution. The Schwinger effect in ${\\rm AdS}_2$ is computed via the phase-integral method in the static coordinates. The Hawking radiation and Schwinger effect of a charged black hole is rederived and interpreted via the phase-integral. Finally, we discuss the relation between the vacuum persistence and the trace or gravitational anomalies.
Spherical Accretion of Matter by Charged Black Holes on f(T) Gravity
Rodrigues, Manuel E
2016-01-01
We studied the spherical accretion of matter by charged black holes on $f(T)$ Gravity. Considering the accretion model of a isentropic perfect fluid we obtain the general form of the Hamiltonian and the dynamic system for the fluid. We have analysed the movements of an isothermal fluid model with $p=\\omega e$ and where $p$ is the pressure and $e$ the total energy density. The analysis of the cases shows the possibility of spherical accretion of fluid by black holes, revealing new phenomena as cyclical movement inside the event horizon.
On five-dimensional non-extremal charged black holes and FRW cosmology
Lópes-Cardoso, G
2008-01-01
We consider static non-extremal charged black hole solutions in the context of N=2 gauged supergravity theories in five dimensions, and we show that they satisfy first-order flow equations. Then we analyze the motion of the dual brane in these black hole backgrounds. We express the entropy in terms of a Cardy-Verlinde-type formula, and we show that the equations describing the FRW cosmology on the brane have a form that is similar to the equations for the entropy and for the Casimir energy on the brane. We also briefly comment on the inclusion of a Gauss-Bonnet term in the analysis.
Tunnelling of scalar and Dirac particles from squashed charged rotating Kaluza-Klein black holes
Energy Technology Data Exchange (ETDEWEB)
Stetsko, M.M. [Ivan Franko National University of Lviv, Department of Theoretical Physics, Lviv (Ukraine)
2016-02-15
The thermal radiation of scalar particles and Dirac fermions from squashed charged rotating five-dimensional black holes is considered. To obtain the temperature of the black holes we use the tunnelling method. In the case of scalar particles we make use of the Hamilton-Jacobi equation. To consider tunnelling of fermions the Dirac equation was investigated. The examination shows that the radial parts of the action for scalar particles and fermions in the quasi-classical limit in the vicinity of horizon are almost the same and as a consequence it gives rise to identical expressions for the temperature in the two cases. (orig.)
Tunnelling of scalar and Dirac particles from squashed charged rotating Kaluza-Klein black holes
Stetsko, M. M.
2016-02-01
The thermal radiation of scalar particles and Dirac fermions from squashed charged rotating five-dimensional black holes is considered. To obtain the temperature of the black holes we use the tunnelling method. In the case of scalar particles we make use of the Hamilton-Jacobi equation. To consider tunnelling of fermions the Dirac equation was investigated. The examination shows that the radial parts of the action for scalar particles and fermions in the quasi-classical limit in the vicinity of horizon are almost the same and as a consequence it gives rise to identical expressions for the temperature in the two cases.
Quasinormal modes of four-dimensional topological nonlinear charged Lifshitz black holes
Energy Technology Data Exchange (ETDEWEB)
Becar, Ramon [Universidad Cato lica de Temuco, Departamento de Ciencias Matematicas y Fisicas, Temuco (Chile); Gonzalez, P.A. [Universidad Diego Portales, Facultad de Ingenieria, Santiago (Chile); Vasquez, Yerko [Universidad de La Serena, Departamento de Fisica, Facultad de Ciencias, La Serena (Chile)
2016-02-15
We study scalar perturbations of four- dimensional topological nonlinear charged Lifshitz black holes with spherical and plane transverse sections, and we find numerically the quasinormal modes for scalar fields. Then we study the stability of these black holes under massive and massless scalar field perturbations. We focus our study on the dependence of the dynamical exponent, the nonlinear exponent, the angular momentum, and the mass of the scalar field in the modes. It is found that the modes are overdamped, depending strongly on the dynamical exponent and the angular momentum of the scalar field for a spherical transverse section. In contrast, for plane transverse sections the modes are always overdamped. (orig.)
Magnetic Dilaton Rotating Strings in the Presence of Exponential Nonlinear Electrodynamics
Sheykhi, A.; Mahmoudi, Z.
2016-09-01
In this paper, we construct a new class of four-dimensional spinning magnetic dilaton string solutions which produces a longitudinal nonlinear electromagnetic field. The Lagrangian of the matter field has the exponential form. We study the physical properties of the solution in ample details. Geometrical, causal and geodisical structures of the solutions are investigated, separately. We confirm that the spacetime is both null and geodesically complete. We find that these solutions have no curvature singularity and no horizon, but have a conic geometry. We investigate the effects of variation of charge and the intensity of the dilaton field, on the deficit angle. Due to the presence of the dilaton field, the asymptotic behavior of the solutions are neither flat nor (anti-) de Sitter [(A)dS]. Furthermore, we extend our study to the higher dimensions and obtain the ( n+1)-dimensional magnetic rotating dilaton strings with k≤[ n/2] rotation parameters and calculate conserved quantities of the solutions. Although these solutions are not asymptotically (A)dS, we use counterterm method to calculate conserved quantities. We also calculate electric charge and show that the net electric charge of the spinning string is proportional to the rotating parameter and the electric field only exists when the rotation parameter does not vanish.
Phase transitions in charged topological black holes dressed with a scalar hair
Martínez, Cristián; Montecinos, Alejandra
2010-12-01
Phase transitions in charged topological black holes dressed with a scalar field are studied. These black holes are solutions of the Einstein-Maxwell theory with a negative cosmological constant and a conformally coupled real self-interacting scalar field. Comparing, in the grand canonical ensemble, the free energies of the hairy and undressed black holes two different phase transitions are found. The first of them is one of second-order type and it occurs at a temperature defined by the value of the cosmological constant. Below this temperature an undressed black hole spontaneously acquires a scalar hair. The other phase transition is one of first-order type. The corresponding critical temperature, which is bounded from above by the one of the previous case, strongly depends on the coupling constant of the quartic self-interaction potential, and this transition only appears when the coupling constant is less than a certain value. In this case, below the critical temperature the undressed black hole is thermodynamically favored. However, when the temperature exceeds the critical value a hairy black hole is likely to be occur.
Time evolution of superradiant instabilities for charged black holes in a cavity
Degollado, Juan Carlos
2013-01-01
Frequency domain studies have recently demonstrated that charged scalar fields exhibit fast growing superradiant instabilities when interacting with charged black holes in a cavity. Here, we present a time domain analysis of the long time evolution of test charged scalar field configurations on the Reissner-Nordstr\\"om background, with or without a mirror-like boundary condition. Initial data is taken to be either a Gaussian wave packet or a regularised (near the horizon) quasi-bound state. Then, Fourier transforming the data obtained in the evolution confirms the results obtained in the frequency domain analysis, in particular for the fast growing modes. We show that spherically symmetric (l=0) modes have even faster growth rates than the l=1 modes for `small' field charge. Thus, our study confirms that this setup is particularly promising for considering the non-linear development of the superradiant instability, since the fast growth makes the signal overcome the numerical error that dominates for small gr...
Rahaman, Farook; Sharma, Ranjan; Tiwari, Rishi Kumar
2014-01-01
We report a 3D charged black hole solution in an anti desetter space inspired by noncommutative geometry.In this construction,the black hole exhibits two horizon which turn into a single horizon in the extreme case.We investigate the impacts of the electromagnetic field on the location of the event horizon,mass and thermodynamic properties such as Hawking temperature,entropy and heat capacity of the black hole.The geodesics of the charged black hole are also analyzed.
Slowly Varying Dilaton Cosmologies and Their Field Theory Duals
Energy Technology Data Exchange (ETDEWEB)
Awad, Adel; /British U. in Egypt /Ain Shams U., Cairo; Das, Sumit R.; Ghosh, Archisman; Oh, Jae-Hyuk; /Kentucky U.; Trivedi, Sandip P.; /Tata Inst. /Stanford U., ITP /SLAC
2011-06-28
We consider a deformation of the AdS{sub 5} x S{sup 5} solution of IIB supergravity obtained by taking the boundary value of the dilaton to be time dependent. The time dependence is taken to be slowly varying on the AdS scale thereby introducing a small parameter {epsilon}. The boundary dilaton has a profile which asymptotes to a constant in the far past and future and attains a minimum value at intermediate times. We construct the sugra solution to first non-trivial order in {epsilon}, and find that it is smooth, horizon free, and asymptotically AdS{sub 5} x S{sup 5} in the far future. When the intermediate values of the dilaton becomes small enough the curvature becomes of order the string scale and the sugra approximation breaks down. The resulting dynamics is analysed in the dual SU(N) gauge theory on S{sup 3} with a time dependent coupling constant which varies slowly. When N{epsilon} << 1, we find that a quantum adiabatic approximation is applicable, and use it to argue that at late times the geometry becomes smooth AdS{sub 5} x S{sup 5} again. When N{epsilon} >> 1, we formulate a classical adiabatic perturbation theory based on coherent states which arises in the large N limit. For large values of the tHooft coupling this reproduces the supergravity results. For small 'tHooft coupling the coherent state calculations become involved and we cannot reach a definite conclusion. We argue that the final state should have a dual description which is mostly smooth AdS5 space with the possible presence of a small black hole.
Penrose inequalities and a positive mass theorem for charged black holes in higher dimension
de Lima, Levi Lopes; Lozório, Weslley; Silva, Juscelino
2014-01-01
We use the inverse mean curvature flow to establish Penrose-type inequalities for time-symmetric Einstein-Maxwell initial data sets which can be suitably embedded as a hypersurface in Euclidean space $\\mathbb R^{n+1}$, $n\\geq 3$. In particular, we prove a positive mass theorem for this class of charged black holes. As an application we show that the conjectured upper bound for the area in terms of the mass and the charge, which in dimension $n=3$ is relevant in connection with the Cosmic Censorship Conjecture, always holds under the natural assumption that the horizon is stable as a minimal hypersurface.
The Hawking radiation of the charged particle via tunnelling from the axisymmetric Sen black hole
Institute of Scientific and Technical Information of China (English)
Jiang Qing-Quan; Yang Shu-Zheng; Chen De-You
2006-01-01
Extending Parikh's semi-classical quantum tunnelling model, this paper has studied the Hawking radiation of the charged particle via tunnelling from the horizon of the axisymmetric Sen black hole. Different from the uncharged massless particle, the geodesies of the charged massive particle tunnelling from the horizon is not light-like. The derived result supports Parikh's opinion and provides a correct modification to Hawking strictly thermal spectrum developed by the fixed background space-time and not considering the energy conservation and the self-gravitation interaction.
Critical behavior of charged black holes in Gauss-Bonnet gravity`s rainbow
Hendi, Seyed Hossein; Panah, Behzad Eslam; Faizal, Mir; Momennia, Mehrab
2016-01-01
Following an earlier study regarding Gauss-Bonnet-Maxwell black holes in the presence of gravity's rainbow [S. H. Hendi and M. Faizal, Phys. Rev. D 92, 044027 (2015)], in this paper, we will consider all constants as energy dependent ones. The geometrical and thermodynamical properties of this generalization are studied and the validation of the first law of thermodynamics is examined. Next, through the use of proportionality between cosmological constant and thermodynamical pressure, van der Waals-like behavior of these black holes in extended phase space is investigated. An interesting critical behavior for sets of rainbow functions in this case is reported. Also, the critical behavior of uncharged and charged solutions is analyzed and it is shown that the generalization to a charged case puts an energy dependent restriction on values of different parameters.
Energy of a Stringy Charged Black Hole in the Teleparallel Gravity
Salti, M
2006-01-01
We use the teleparallel geometry analog of the Moller energy-momentum complex to calculate the energy distribution (due to matter plus field including gravity) of a charged black hole solution in heterotic string theory. We find the same energy distribution as obtained by Gad who investigated the same problem by using the Moller energy-momentum complex in general relativity. The total energy depends on the black hole mass M and charge Q. The energy obtained is also independent of the teleparallel dimensionless coupling constant, which means that it is valid not only in the teleparallel equivalent of general relativity, but also in any teleparallel model. Furthermore, our results also sustains (a) the importance of the energy-momentum definitions in the evaluation of the energy distribution of a given spacetime and (b) the viewpoint of Lessner that the Moller energy-momentum complex is a powerful concept of energy and momentum.
Thermodynamic stability of charged BTZ black holes: Ensemble dependency problem and its solution
Hendi, S H; Mamasani, R
2015-01-01
Motivated by the wide applications of thermal stability and phase transition, we investigate thermodynamic properties of charged BTZ black holes. We apply the standard method to calculate the heat capacity and the Hessian matrix and find that thermal stability of charged BTZ solutions depends on the choice of ensemble. To overcome this problem, we take into account cosmological constant as a thermodynamical variable. By this modification, we show that the ensemble dependency is eliminated and thermal stability conditions are the same in both ensembles. Then, we generalize our solutions to the case of nonlinear electrodynamics. We show how nonlinear matter field modifies the geometrical behavior of the metric function. We also study phase transition and thermal stability of these black holes in context of both canonical and grand canonical ensembles. We show that by considering the cosmological constant as a thermodynamical variable and modifying the Hessian matrix, the ensemble dependency of thermal stability...
Stationary BPS solutions to dilaton-axion gravity
Clément, G
1996-01-01
Stationary four-dimensional BPS solutions to gravity coupled bosonic theories admitting a three--dimensional sigma--model representation on coset spaces are interpreted as null geodesics of the target manifold equipped with a certain number of harmonic maps. For asymptotically flat (or Taub--NUT) space--times such geodesics can be directly parametrized in terms of charges saturating the Bogomol'nyi--Gibbons--Hull bound, and classified according to the structure of related coset matrices. We investigate in detail the ``dilaton--axion gravity'' with one vector field, and show that in the space of BPS solutions an SO(1,2) \\times SO(2) classical symmetry is acting. Within the present formalism the most general multicenter (IWP/Taub--NUT dyon) solutions are derived in a simple way. We also discover a large new class of asymptotically flat solutions for which the dilaton and axion charges are constrained only by the BPS bound. The string metrics for these solutions are generically regular. Both the IWP class and th...
Phase transition of charged Black Holes in Brans-Dicke theory through geometrical thermodynamics
Hendi, S H; Panah, B Eslam; Armanfard, Z
2015-01-01
In this paper, we take into account black hole solutions of Brans-Dicke-Maxwell theory and investigate their stability and phase transition points. We apply the concept of geometry in thermodynamics to obtain phase transition points and compare its results with those of calculated in canonical ensemble through heat capacity. We show that these black holes enjoy second order phase transitions. We also show that there is a lower bound for the horizon radius of physical charged black holes in Brans-Dicke theory which is originated from restrictions of positivity of temperature. In addition, we find that employing specific thermodynamical metric in the context of geometrical thermodynamics yields divergencies for thermodynamical Ricci scalar in places of phase transitions. It will be pointed out that due to characteristics behavior of thermodynamical Ricci scalar around its divergence points, one is able to distinguish the physical limitation point from the phase transitions.
Phase transitions in higher derivative gravity and gauge theory: R-charged black holes
Dey, Tanay K.; Mukherji, Sudipta; Mukhopadhyay, Subir; Sarkar, Swarnendu
2007-09-01
This is a continuation of our earlier work where we constructed a phenomenologically motivated effective action of the boundary gauge theory at finite temperature and finite gauge coupling on S3 × S1. In this paper, we argue that this effective action qualitatively reproduces the gauge theory representing various bulk phases of R-charged black hole with Gauss-Bonnet correction. We analyze the system both in canonical and grand canonical ensemble.
Phase transitions in higher derivative gravity and gauge theory: R-charged black holes
Dey, Tanay K; Mukhopadhyay, Subir; Sarkar, Swarnendu
2007-01-01
This is a continuation of our earlier work where we constructed a phenomenologically motivated effective action of the boundary gauge theory at finite temperature and finite gauge coupling on $S^3 \\times S^1$. In this paper, we argue that this effective action qualitatively reproduces the gauge theory representing various bulk phases of R-charged black hole with Gauss-Bonnet correction. We analyze the system both in canonical and grand canonical ensemble.
A study of geodesic motion in a (2+1)-dimensional charged BTZ black hole
Soroushfar, Saheb; Jafari, Afsaneh
2015-01-01
This study is purposed to derive the equation of motion for geodesics in vicinity of spacetime of a (2 + 1)-dimensional charged BTZ black hole. In this paper, we solve geodesics for both massive and massless particles in terms of Weierstrass elliptic and Kleinian sigma hyper-elliptic functions. Then we determine different trajectories of motion for particles in terms of conserved energy and angular momentum and also using effective potential.
Flat Symplectic Bundles of N-Extended Supergravities, Central Charges and Black-Hole Entropy
Andrianopoli, Laura; Ferrara, Sergio
1998-01-01
In these lectures we give a geometrical formulation of N-extended supergravities which generalizes N=2 special geometry of N=2 theories. In all these theories duality symmetries are related to the notion of "flat symplectic bundles" and central charges may be defined as "sections" over these bundles. Attractor points giving rise to "fixed scalars" of the horizon geometry and Bekenstein-Hawking entropy formula for extremal black-holes are discussed in some details.
Stuchlík, Zdeněk
2015-01-01
To test the role of large-scale magnetic fields in accretion processes, we study dynamics of charged test particles in vicinity of a black hole immersed into an asymptotically uniform magnetic field. Using the Hamiltonian formalism of charged particle dynamics, we examine chaotic scattering in the effective potential related to the black hole gravitational field combined with the uniform magnetic field. Energy interchange between the translational and oscillatory modes od the charged particle dynamics provides mechanism for charged particle acceleration along the magnetic field lines. This energy transmutation is an attribute of the chaotic charged particle dynamics in the combined gravitational and magnetic fields only, the black hole rotation is not necessary for such charged particle acceleration. The chaotic scatter can cause transition to the motion along the magnetic field lines with small radius of the Larmor motion or vanishing Larmor radius, when the speed of the particle translational motion is larg...
Thermodynamics of Charged Black Holes in Einstein-Horndeski-Maxwell Theory
Feng, Xing-Hui; Lü, H; Pope, C N
2015-01-01
We extend an earlier investigation of the thermodynamics of static black holes in an Einstein-Horndeski theory of gravity coupled to a scalar field, by including now an elec- tromagnetic field as well. By studying the two-parameter families of charged static black holes, we obtain much more powerful constraints on the thermodynamics since, unlike in the uncharged one-parameter case, now the right-hand side of the first law is not automatically integrable. In fact, this allows us to demonstrate that there must be an additional contribution in the first law, over and above the usual terms expected for charged black holes. The origin of the extra contribution can be attributed to the behaviour of the scalar field on the horizon of the black hole. We carry out the calculations in four dimensions and also in general dimensions. We also derive the ratio of viscosity to entropy for the dual boundary field theory, showing that the usual viscosity bound for isotropic solutions can be violated, with the ratio depending...
Charged Rotating Black Branes in anti-de Sitter Einstein-Gauss-Bonnet Gravity
Dehghani, M H
2003-01-01
We present a new class of charged rotating solutions in the Einstein-Gauss-Bonnet gravity with a negative cosmological constant. These solutions may be interpreted as black brane solutions with two inner and outer event horizons or an extreme black brane depending on the value of the mass parameter $m$. We also find that the Killing vectors are the null generators of the event horizon. The physical properties of the brane such as the temperature, the angular velocity, the entropy, the electric charge and potential are computed. We also compute the action and the Gibbs potential as a function of temperature and angular velocity for the uncharged solutions, and compute the angular momentum and the mass of the black brane through the use of Gibbs potential. We show that these thermodynamic quantities satisfy the first law of thermodynamics. We also perform a local stability analysis of the asymptotically AdS uncharged rotating black brane in various dimensions and show that they are locally stable for the whole ...
Superradiance and instability of small rotating charged AdS black holes in all dimensions
Energy Technology Data Exchange (ETDEWEB)
Aliev, Alikram N. [Yeni Yuezyil University, Faculty of Engineering and Architecture, Istanbul (Turkey)
2016-02-15
Rotating small AdS black holes exhibit the superradiant instability to low-frequency scalar perturbations, which is amenable to a complete analytic description in four dimensions. In this paper, we extend this description to all higher dimensions, focusing on slowly rotating charged AdS black holes with a single angular momentum. We divide the spacetime of these black holes into the near-horizon and far regions and find solutions to the scalar wave equation in each of these regions. Next, we perform the matching of these solutions in the overlap between the regions, by employing the idea that the orbital quantum number l can be thought of as an approximate integer. Thus, we obtain the complete low-frequency solution that allows us to calculate the complex frequency spectrum of quasinormal modes, whose imaginary part is determined by a small damping parameter. Finally, we find a remarkably instructive expression for the damping parameter, which appears to be a complex quantity in general. We show that the real part of the damping parameter can be used to give a universal analytic description of the superradiant instability for slowly rotating charged AdS black holes in all spacetime dimensions. (orig.)
Back reaction, the Hawking emission spectrum from the charged black hole
Energy Technology Data Exchange (ETDEWEB)
Xu Pingchuan; Wang Zhihong [Institute of Theoretical Physics, China West Normal University, Nanchong, Sichuan 637002 (China); Han Yan, E-mail: pcxu@163.com [College of Mathematic and Information, China West Normal University, Nanchong, Sichuan 637002 (China)
2011-06-21
The Hawking emission spectrum of the Schwarzschild-like black hole has been successfully described in the tunneling picture. In this paper, we develop the idea for the case of the charged black hole with back reaction. First, the most general, static spherically symmetric charged black hole, in the presence of back reaction, has been provided by solving the Einstein equations with a non-zero vacuum expectation value of the energy-momentum tensor (T{sub {mu}{nu}}({phi}, g{sub {mu}{nu}})). At the one-loop corrections, we also produce the modified expressions for the Hawking temperature and Bekenstein-Hawking entropy. It is found that the leading correction to the semiclassical entropy is logarithmic and next to the leading order is inverse of the horizon area, just as the expected well-known results. In particular, as our main focus in this paper, we show that the modified black hole still radiates with a perfect blackbody spectrum, only the temperature undergoing quantum corrections. Also, the Hawking fluxes of the electric current and energy-momentum tensor to include the effect of back reaction are obtained. The results are interestingly found sharing the same form as that from the point of anomaly.
Bertotti-Robinson type solutions to Dilaton-Axion Gravity
Clément, G; Clement, Gerard; Gal'tsov, Dmitri
2001-01-01
We present a new solution to dilaton-axion gravity which looks like a rotating Bertotti-Robinson (BR) Universe. It is supported by an homogeneous Maxwell field and a linear axion and can be obtained as a near-horizon limit of extremal rotating dilaton-axion black holes. It has the isometry $SL(2,R)\\times U(1)$ where U(1) is the remnant of the SO(3) symmetry of BR broken by rotation, while $SL(2,R)$ corresponds to the $AdS_2$ sector which no longer factors out of the full spacetime. Alternatively our solution can be obtained from the D=5 vacuum counterpart to the dyonic BR with equal electric and magnetic field strengths. The derivation amounts to smearing it in D=6 and then reducing to D=4 with dualization of one Kaluza-Klein two-form in D=5 to produce an axion. Using a similar dualization procedure, the rotating BR solution is uplifted to D=11 supergravity. We show that it breaks all supersymmetries of N=4 supergravity in D=4, and that its higher dimensional embeddings are not supersymmetric either. But, hop...
Entropy of an extremal electrically charged thin shell and the extremal black hole
Lemos, José P S; Zaslavskii, Oleg B
2015-01-01
There is a debate as to what is the value of the the entropy $S$ of extremal black holes. There are approaches that yield zero entropy $S=0$, while there are others that yield the Bekenstein-Hawking entropy $S=A_+/4$, in Planck units. There are still other approaches that give that $S$ is proportional to $r_+$ or even that $S$ is a generic well-behaved function of $r_+$. Here $r_+$ is the black hole horizon radius and $A_+=4\\pi r_+^2$ is its horizon area. Using a thin matter shell with extremal electric charge, we find the entropy expression for the extremal thin shell spacetime. When the shell's radius approaches its own gravitational radius, and thus turns into an extremal black hole, we encounter that the entropy is $S=S(r_+)$, i.e., the entropy of an extremal black hole is a function of $r_+$ alone. We speculate that the range of values for the entropy of an extremal black hole is $0\\leq S(r_+) \\leq A_+/4$.
Phase transitions in charged topological black holes dressed with a scalar hair
Martinez, Cristian
2010-01-01
Phase transitions in charged topological black holes dressed with a scalar field are studied. These black holes are solutions of the Einstein-Maxwell theory with a negative cosmological constant and a conformally coupled real self-interacting scalar field. Comparing, in the grand canonical ensemble, the free energies of the hairy and undressed black holes two different phase transitions are found. The first of them is one of second-order type and it occurs at a temperature defined by the value of the cosmological constant. Below this temperature an undressed black hole spontaneously acquires a scalar hair. The other phase transition is one of first-order type. The corresponding critical temperature, which is bounded from above by the one of the previous case, strongly depends on the coupling constant of the quartic self-interaction potential, and this transition only appears when the coupling constant is less than a certain value. In this case, below the critical temperature the undressed black is thermodynam...
Entropy of an extremal electrically charged thin shell and the extremal black hole
Directory of Open Access Journals (Sweden)
José P.S. Lemos
2015-11-01
Full Text Available There is a debate as to what is the value of the entropy S of extremal black holes. There are approaches that yield zero entropy S=0, while there are others that yield the Bekenstein–Hawking entropy S=A+/4, in Planck units. There are still other approaches that give that S is proportional to r+ or even that S is a generic well-behaved function of r+. Here r+ is the black hole horizon radius and A+=4πr+2 is its horizon area. Using a spherically symmetric thin matter shell with extremal electric charge, we find the entropy expression for the extremal thin shell spacetime. When the shell's radius approaches its own gravitational radius, and thus turns into an extremal black hole, we encounter that the entropy is S=S(r+, i.e., the entropy of an extremal black hole is a function of r+ alone. We speculate that the range of values for an extremal black hole is 0≤S(r+≤A+/4.
Axion-dilaton cosmology and dark energy
Energy Technology Data Exchange (ETDEWEB)
Catena, R.; Moeller, J.
2007-09-15
We discuss a class of flat FRW cosmological models based on D=4 axion-dilaton gravity universally coupled to cosmological background fluids. In particular, we investigate the possibility of recurrent acceleration, which was recently shown to be generically realized in a wide class of axion-dilaton models, but in absence of cosmological background fluids. We observe that, once we impose the existence of radiation - and matter - dominated earlier stages of cosmic evolution, the axion-dilaton dynamics is altered significantly with respect to the case of pure axion-dilaton gravity. During the matter dominated epoch the scalar fields remain either frozen, due to the large expansion rate, or enter a cosmological scaling regime. In both cases, oscillations of the effective equation of state around the acceleration boundary value are impossible. Models which enter an oscillatory stage in the low redshift regime, on the other hand, are disfavored by observations. We also comment on the viability of the axion-dilaton system as a candidate for dynamical dark energy. In a certain subclass of models, an intermediate scaling regime is succeeded by eternal acceleration. We also briefly discuss the issue of dependence on initial conditions. (orig.)
The charged black-hole bomb: A lower bound on the charge-to-mass ratio of the explosive scalar field
Hod, Shahar
2016-01-01
The well-known superradiant amplification mechanism allows a charged scalar field of proper mass $\\mu$ and electric charge $q$ to extract the Coulomb energy of a charged Reissner-Nordstr\\"om black hole. The rate of energy extraction can grow exponentially in time if the system is placed inside a reflecting cavity which prevents the charged scalar field from escaping to infinity. This composed black-hole-charged-scalar-field-mirror system is known as the {\\it charged black-hole bomb}. Previous numerical studies of this composed physical system have shown that, in the linearized regime, the inequality $q/\\mu>1$ provides a necessary condition for the development of the superradiant instability. In the present paper we use analytical techniques to study the instability properties of the charged black-hole bomb in the regime of linearized scalar fields. In particular, we prove that the lower bound ${{q}\\over{\\mu}}>\\sqrt{{{r_{\\text{m}}/r_--1}\\over{r_{\\text{m}}/r_+-1}}}$ provides a necessary condition for the develo...
Conserved charges of black holes in Weyl and Einstein-Gauss-Bonnet gravities
Energy Technology Data Exchange (ETDEWEB)
Peng, Jun-Jin [SEEE, Wuhan Textile University, Institute of Technical Physics, Wuhan, Hubei (China); Chinese Academy of Sciences, Kavli Institute for Theoretical Physics China, Institute of Theoretical Physics, P.O. Box 2735, Beijing (China)
2014-11-15
An off-shell generalization of the Abbott-Deser-Tekin (ADT) conserved charge was recently proposed by Kim et al. They achieved this by introducing off-shell Noether currents and potentials. In this paper, we construct the crucial off-shell Noether current by the variation of the Bianchi identity for the expression of EOM, with the help of the property of Killing vector. Our Noether current, which contains an additional term that is just one half of the Lie derivative of a surface term with respect to the Killing vector, takes a different form in comparison with the one in their work. Then we employ the generalized formulation to calculate the quasi-local conserved charges for the most general charged spherically symmetric and the dyonic rotating black holes with AdS asymptotics in four-dimensional conformal Weyl gravity, as well as the charged spherically symmetric black holes in arbitrary dimensional Einstein-Gauss-Bonnet gravity coupled to Maxwell or nonlinear electrodynamics in AdS spacetime. Our results confirm those obtained through other methods in the literature. (orig.)
Gußmann, Alexander
2017-03-01
The existence of the classical black hole solutions of the Einstein–Yang–Mills–Higgs equations with non-Abelian Yang–Mills–Higgs hair implies that not all classical stationary magnetically charged black holes can be uniquely described by their asymptotic characteristics. In fact, in a certain domain of parameters, there exist different spherically-symmetric, non-rotating and asymptotically-flat classical black hole solutions of the Einstein–Yang–Mills–Higgs equations which have the same ADM mass and the same magnetic charge but significantly different geometries in the near-horizon regions. (These are black hole solutions which are described by a Reissner–Nordström metric on the one hand and the black hole solutions with non-Abelian Yang–Mills–Higgs hair which are described by a metric which is not of Reissner–Nordström form on the other hand). One can experimentally distinguish such black holes with the same asymptotic characteristics but different near-horizon geometries classically by probing the near-horizon regions of the black holes. We argue that one way to probe the near-horizon region of a black hole which allows one to distinguish magnetically charged black holes with the same asymptotic characteristics but different near-horizon geometries is by classical scattering of waves. Using the example of a minimally-coupled massless probe scalar field scattered by magnetically charged black holes which can be obtained as solutions of the Einstein–Yang–Mills–Higgs equations with a Higgs triplet and gauge group SU(2) in the limit of an infinite Higgs self-coupling constant we show how, in this case, the scattering cross sections differ for the magnetically charged black holes with different near-horizon geometries but the same asymptotic characteristics. We find in particular that the characteristic glory peaks in the cross sections are located at different scattering angles.
Analytic treatment of the charged black-hole-mirror bomb in the highly explosive regime
Hod, Shahar
2013-01-01
A charged scalar field impinging upon a charged Reissner-Nordstrom black hole can be amplified as it scatters off the hole, a phenomenon known as superradiant scattering. This scattering process in the superradiant regime w>1 and for mirror radii r_m in the near-horizon region x_m=(r_m-r_+)/r_+>(tau/x_m)^2>>1 regime, which implies that the instability timescale 1/w_I of the system can be made arbitrarily short in the qQ-->infinity limit. The short instability timescale found in the linear regime along with the spherical symmetry of the system, make the charged bomb a convenient toy model for future numerical studies aimed to investigate the non-linear end-state of superradiant instabilities.
Firsova, N E
1998-01-01
We study a correct statement of the scattering problem arising for quantum charged scalar particles on the Reissner-Nordström black holes when taking into account the own electric field of black hole. The elements of the corresponding S-matrix are explored in the form convenient to physical applications and for applying numerical methods. Some further possible issues are outlined.
Analytic treatment of the system of a Kerr-Newman black hole and a charged massive scalar field
Hod, Shahar
2016-08-01
Charged rotating Kerr-Newman black holes are known to be superradiantly unstable to perturbations of charged massive bosonic fields whose proper frequencies lie in the bounded regime 0 eikonal large-mass regime, the superradiant instability growth rates of the explosive scalar fields are characterized by a nontrivial (nonmonotonic) dependence on the dimensionless charge-to-mass ratio q /μ . In particular, for given parameters {M ,Q ,J } of the central Kerr-Newman black hole, we determine analytically the optimal charge-to-mass ratio q /μ of the explosive scalar field which maximizes the growth rate of the superradiant instabilities in the composed Kerr-Newman-black-hole-charged-massive-scalar-field system.
Absorption Cross Section of Static Einstein-Maxwell Dilation Axion Black Hole for Scalar Particles
Institute of Scientific and Technical Information of China (English)
LIU Chang-Qing; JING Ji-Liang
2007-01-01
The absorption cross section of the static Einstein-Maxwell dilaton axion (EMDA) black hole for scalar particles is investigated.It is shown that the ratio of the absorption cross section of the EMDA black hole to that of the Schwarzschild black hole decreases as the absolute value of the dilaton increases,and it becomes zero as the dilaton tends to its extremal value.It is also shown that the absorption cross section decreases as both the v and the absolute value of the dilaton increase,and it decreases as the mass of the particle decreases.
Thermodynamics of Intersecting Black Branes from Interacting Elementary Branes
Morita, Takeshi
2015-01-01
If an Einstein-Maxwell-Dilaton system admits the extreme brane solution in which no force works between the parallel branes, the collective motion of nearly parallel branes exhibits the thermodynamical properties which are coincident with those of the corresponding black branes at low energy regime (up to unfixed numerical factors). Hence it may provide the microscopic description of the black branes ($p$-soup proposal). This fact motivates us to test this proposal in the intersecting black branes which have multiple brane charges and/or momentum along the brane direction. We consider the case that the multiple branes satisfy the intersection rule and feel no force when they are static, and find the agreement to the black hole thermodynamics.
Rapid growth of superradiant instabilities for charged black holes in a cavity
Herdeiro, Carlos A R; Rúnarsson, Helgi Freyr
2013-01-01
Confined scalar fields, either by a mass term or by a mirror-like boundary condition, have unstable modes in the background of a Kerr black hole. Assuming a time dependence as $e^{-i\\omega t}$, the growth time-scale of these unstable modes is set by the inverse of the (positive) imaginary part of the frequency, Im$(\\omega)$, which reaches a maximum value of the order of Im$(\\omega)M\\sim 10^{-5}$, attained for a mirror-like boundary condition, where $M$ is the black hole mass. In this paper we study the minimally coupled Klein-Gordon equation for a charged scalar field in the background of a Reissner-Nordstr\\"om black hole and show that the unstable modes, due to a mirror-like boundary condition, can grow several orders of magnitude faster than in the rotating case: we have obtained modes with up to Im$(\\omega)M\\sim 0.07$. We provide an understanding, based on an analytic approximation, to why the instability in the charged case has a smaller timescale than in the rotating case. This faster growth, together wi...
Phase transition of charged Black Holes in Brans-Dicke theory through geometrical thermodynamics
Hendi, S. H.; Panahiyan, S.; Panah, B. Eslam; Armanfard, Z.
2016-07-01
In this paper, we take into account black hole solutions of Brans-Dicke-Maxwell theory and investigate their stability and phase transition points. We apply the concept of geometry in thermodynamics to obtain phase transition points and compare its results with those, calculated in the canonical ensemble through heat capacity. We show that these black holes enjoy second order phase transitions. We also show that there is a lower bound for the horizon radius of physical charged black holes in Brans-Dicke theory, which originates from restrictions of positivity of temperature. In addition, we find that employing a specific thermodynamical metric in the context of geometrical thermodynamics yields divergencies for the thermodynamical Ricci scalar in places of the phase transitions. It will be pointed out that due to the characteristic behavior of the thermodynamical Ricci scalar around its divergence points, one is able to distinguish the physical limitation point from the phase transitions. In addition, the free energy of these black holes will be obtained and its behavior will be investigated. It will be shown that the behavior of the free energy in the place where the heat capacity diverges demonstrates second order phase transition characteristics.
On the near horizon rotating black hole geometries with NUT charges
Energy Technology Data Exchange (ETDEWEB)
Galajinsky, Anton; Orekhov, Kirill [Tomsk Polytechnic University, Laboratory of Mathematical Physics, Tomsk (Russian Federation)
2016-09-15
The near horizon geometries are usually constructed by implementing a specific limit to a given extreme black hole configuration. Their salient feature is that the isometry group includes the conformal subgroup SO(2, 1). In this work, we turn the logic around and use the conformal invariants for constructing Ricci-flat metrics in d = 4 and d = 5 where the vacuum Einstein equations reduce to a coupled set of ordinary differential equations. In four dimensions the analysis can be carried out in full generality and the resulting metric describes the d = 4 near horizon Kerr-NUT black hole. In five dimensions we choose a specific ansatz whose structure is similar to the d = 5 near horizon Myers-Perry black hole. A Ricci-flat metric involving five arbitrary parameters is constructed. A particular member of this family, which is characterized by three parameters, seems to be a natural candidate to describe the d = 5 near horizon Myers- Perry black hole with a NUT charge. (orig.)
Blázquez-Salcedo, Jose Luis; Navarro-Lérida, Francisco; Radu, Eugen
2016-01-01
We consider rotating black hole solutions in five-dimensional Einstein-Maxwell-Chern-Simons theory with a negative cosmological constant and a generic value of the Chern-Simons coupling constant $\\lambda$. Using both analytical and numerical techniques, we focus on cohomogeneity-1 configurations, with two equal-magnitude angular momenta, which approach at infinity a globally AdS background. We find that the generic solutions share a number of basic properties with the known Cvetic, L\\"u and Pope black holes which have $\\lambda=1$. New features occur as well, for example, when the Chern-Simons coupling constant exceeds a critical value, the solutions are no longer uniquely determined by their global charges. Moreover, the black holes possess radial excitations which can be labelled by the node number of the magnetic gauge potential function. Solutions with small values of $\\lambda$ possess other distinct features. For instance, the extremal black holes there form two disconnected branches, while not all near-h...
On the near horizon rotating black hole geometries with NUT charges
Galajinsky, Anton; Orekhov, Kirill
2016-09-01
The near horizon geometries are usually constructed by implementing a specific limit to a given extreme black hole configuration. Their salient feature is that the isometry group includes the conformal subgroup SO(2, 1). In this work, we turn the logic around and use the conformal invariants for constructing Ricci-flat metrics in d=4 and d=5 where the vacuum Einstein equations reduce to a coupled set of ordinary differential equations. In four dimensions the analysis can be carried out in full generality and the resulting metric describes the d=4 near horizon Kerr-NUT black hole. In five dimensions we choose a specific ansatz whose structure is similar to the d=5 near horizon Myers-Perry black hole. A Ricci-flat metric involving five arbitrary parameters is constructed. A particular member of this family, which is characterized by three parameters, seems to be a natural candidate to describe the d=5 near horizon Myers-Perry black hole with a NUT charge.
On the near horizon rotating black hole geometries with NUT charges
Galajinsky, Anton
2016-01-01
The near horizon geometries are usually constructed by implementing a specific limit to a given extreme black hole configuration. Their salient feature is that the isometry group includes the conformal subgroup SO(2,1). In this work, we turn the logic around and use the conformal invariants for constructing Ricci-flat metrics in d=4 and d=5 where the vacuum Einstein equations reduce to a coupled set of ordinary differential equations. In four dimensions the analysis can be carried out in full generality and the resulting metric describes the d=4 near horizon Kerr-NUT black hole. In five dimensions we choose a specific ansatz whose structure is similar to the d=5 near horizon Myers-Perry black hole. A Ricci-flat metric involving five arbitrary parameters is constructed. A particular member of this family, which is characterized by three parameters, seems to be a natural candidate to describe the d=5 near horizon Myers-Perry black hole with a NUT charge.
Quantum naked singularities in 2d dilaton gravity
Vaz, C; Vaz, Cenalo; Witten, Louis
1996-01-01
Roughly speaking, naked singularities are singularities that may be seen by timelike observers. The Cosmic Censorship conjecture forbids their existence by stating that a reasonable system of energy will not, under reasonable conditions, collapse into a naked singularity. There are however many counter-examples to this conjecture in the literature. We propose a defense of the conjecture through the quantum theory. We will show that the Hawking effect, when consistently applied to naked singularities in two dimensional models of dilaton gravity with matter and a cosmological constant, prevents their formation by causing them to explode or catastrophically emit radiation, as opposed to black holes which radiate slowly. If this phenomenon is reproduced in the four dimensional world, the explosion of naked singularities should have observable consequences.
Thermodynamic instability of nonlinearly charged black holes in gravity's rainbow
Energy Technology Data Exchange (ETDEWEB)
Hendi, S.H. [Shiraz University, Physics Department and Biruni Observatory, College of Sciences, Shiraz (Iran, Islamic Republic of); Research Institute for Astronomy and Astrophysics of Maragha (RIAAM), Maragha (Iran, Islamic Republic of); Panahiyan, S. [Shiraz University, Physics Department and Biruni Observatory, College of Sciences, Shiraz (Iran, Islamic Republic of); Shahid Beheshti University, Physics Department, Tehran (Iran, Islamic Republic of); Panah, B.E.; Momennia, M. [Shiraz University, Physics Department and Biruni Observatory, College of Sciences, Shiraz (Iran, Islamic Republic of)
2016-03-15
Motivated by the violation of Lorentz invariance in quantum gravity, we study black hole solutions in gravity's rainbow in the context of Einstein gravity coupled with various models of nonlinear electrodynamics. We regard an energy dependent spacetime and obtain the related metric functions and electric fields. We show that there is an essential singularity at the origin which is covered by an event horizon. We also compute the conserved and thermodynamical quantities and examine the validity of the first law of thermodynamics in the presence of rainbow functions. Finally, we investigate the thermal stability conditions for these black hole solutions in the context of canonical ensemble. We show that the thermodynamical structure of the solutions depends on the choices of nonlinearity parameters, charge, and energy functions. (orig.)
da Rocha, Roldao
2014-01-01
The perihelion precession, the deflection of light, and the radar echo delay are classical tests of General Relativity here used to probe brane world topologically charged black holes in a f(R) bulk and to constrain the parameter that arises from the Shiromizu-Maeda-Sasaki procedure applied to a f(R) bulk as well. The existing Solar system observational data constrain the possible values of the tidal charge parameter and the effective cosmological constant including f(R) brane world effects. We show that the observational/experimental data for both perihelion precession and radar echo delay make the black hole space of parameters to be more strict than the ones for the Dadhich, Maartens, Papadopoulos and Rezania (DMPR) black hole geometry. Furthermore, the deflection of light constrains the tidal charge parameter similarly as the DMPR black holes due to a peculiarity in the equation of motion.
Area inequalities for stable marginally outer trapped surfaces in Einstein-Maxwell-dilaton theory
Fajman, David
2013-01-01
We prove area inequalities for stable marginally outer trapped surfaces in Einstein-Maxwell-dilaton theory. Our inspiration comes on the one hand from a corresponding recent upper bound for the area in terms of the charges obtained by Dain, Jaramillo and Reiris [1] in the pure Einstein-Maxwell case without symmetries, and on the other hand from Yazadjiev's inequality [2] in the axially symmetric Einstein-Maxwell-dilaton case. The common issue in these proofs and in the present one is a functional ${\\mathscr W}$ of the matter fields for which the stability condition readily yields an {\\it upper} bound. On the other hand, the step which crucially depends on whether or not a dilaton field is present is to obtain a {\\it lower} bound for ${\\mathscr W}$ as well. We obtain the latter by first setting up a variational principle for ${\\mathscr W}$ with respect to the dilaton field $\\phi$, then by proving existence of a minimizer $\\psi$ as solution of the corresponding Euler-Lagrange equations and finally by estimating...
Charged de Sitter-like black holes: quintessence-dependent enthalpy and new extreme solutions
Energy Technology Data Exchange (ETDEWEB)
Azreg-Ainou, Mustapha [Baskent University, Faculty of Engineering, Ankara (Turkey)
2015-01-01
We consider Reissner-Nordstroem black holes surrounded by quintessence where both a non-extremal event horizon and a cosmological horizon exist besides an inner horizon (-1 ≤ ω < -1/3). We determine new extreme black hole solutions that generalize the Nariai horizon to asymptotically de Sitter-like solutions for any order relation between the squares of the charge q{sup 2} and the mass parameter M{sup 2} provided q{sup 2} remains smaller than some limit, which is larger than M{sup 2}. In the limit case q{sup 2} = 9ω{sup 2}M{sup 2}/(9ω{sup 2}-1), we derive the general expression of the extreme cosmo-blackhole, where the three horizons merge, and we discuss some of its properties.We also show that the endpoint of the evaporation process is independent of any order relation between q{sup 2} and M{sup 2}. The Teitelboim energy and the Padmanabhan energy are related by a nonlinear expression and are shown to correspond to different ensembles. We also determine the enthalpy H of the event horizon, as well as the effective thermodynamic volume which is the conjugate variable of the negative quintessential pressure, and show that in general the mass parameter and the Teitelboim energy are different from the enthalpy and internal energy; only in the cosmological case, that is, for Reissner-Nordstroem-de Sitter black hole we have H = M. Generalized Smarr formulas are also derived. It is concluded that the internal energy has a universal expression for all static charged black holes, with possibly a variable mass parameter, but it is not a suitable thermodynamic potential for static-black-hole thermodynamics if M is constant. It is also shown that the reverse isoperimetric inequality holds. We generalize the results to the case of the Reissner-Nordstroem-de Sitter black hole surrounded by quintessence with two physical constants yielding two thermodynamic volumes. (orig.)
Naturally light dilatons from nearly marginal deformations
Megias, Eugenio
2014-01-01
We discuss the presence of a light dilaton in CFTs deformed by a nearly-marginal operator O, in the holographic realizations consisting of confining RG flows that end on a soft wall. Generically, the deformations induce a condensate , and the dilaton mode can be identified as the fluctuation of . We obtain a mass formula for the dilaton as a certain average along the RG flow. The dilaton is naturally light whenever i) confinement is reached fast enough (such as via the condensation of O) and ii) the beta function is small (walking) at the condensation scale. These conditions are satisfied for a class of models with a bulk pseudo-Goldstone boson whose potential is nearly flat at small field and exponential at large field values. Thus, the recent observation by Contino, Pomarol and Ratazzi holds in CFTs with a single nearly-marginal operator. We also discuss the holographic method to compute the condensate , based on solving the first-order nonlinear differential equation that the beta function satisfies.
Penrose inequalities and a positive mass theorem for charged black holes in higher dimensions
Lopes de Lima, Levi; Girão, Frederico; Lozório, Weslley; Silva, Juscelino
2016-02-01
We use the inverse mean curvature flow to establish Penrose-type inequalities for time-symmetric Einstein-Maxwell initial data sets which can be suitably embedded as a hypersurface in Euclidean space {{{R}}}n+1, n≥slant 3. In particular, we prove a positive mass theorem for this class of charged black holes. As an application, we show that the conjectured upper bound for the area in terms of the mass and the charge, which in dimension n = 3 is relevant in connection with the cosmic censorship conjecture, always holds under the natural assumption that the horizon is stable as a minimal hypersurface. The first and second authors were partially supported by CNPq/Brazil grants. The first and last authors were partially supported by a CAPES/Brazil grant.
Soto-Manriquez, Jose
2016-01-01
A new mechanism for the acceleration of ultra high energy cosmic rays (UHECR) is presented here. It is based on the tunnel-ionization of neutral atoms approaching electrically charged stellar black holes and on the repulsion of the resulting positively charged atomic part by huge, long-range electric fields. Energies above $10^{18}$ eV for these particles are calculated in a simple way by means of this single-shot, all-electrical model. When this acceleration mechanism is combined with the supernova explosions in the galactic halo of the massive runaway stars expelled from the galactic disk, this model predicts nearly the correct values of the measured top energy of the UHECRs and their flux in a specified EeV energy range. It also explains the near isotropy of the arrivals of these energetic particles to Earth, as has been recently measured by the Auger Observatory.
On a regular charged black hole with a nonlinear electric source
Culetu, Hristu
2014-01-01
A modified version of the Reissner-Nordstrom metric is proposed on the grounds of the nonlinear electrodynamics model. The source of curvature is an anisotropic fluid with $p_{r} = -\\rho$ which resembles the Maxwell stress tensor at $r >> q^{2}/2m$, where $q$ and $m$ are the mass and charge of the particle, respectively. We found the black hole horizon entropy obeys the relation $S = |W|/2T = A_{H}/4$, with $W$ the Komar energy and $A_{H}$ the horizon area. The electric field around the source depends not only on its charge but also on its mass. The corresponding electrostatic potential $\\Phi(r)$ is finite everywhere, vanishes at the origin and at $r = q^{2}/6m$ and is nonzero asymptotically, with $\\Phi_{\\infty} = 3m/2q$.
Hod, Shahar
2016-10-01
We determine the characteristic timescales associated with the linearized relaxation dynamics of the composed Reissner-Nordström-black-hole-charged-massive-scalar-field system. To that end, the quasinormal resonant frequencies {ωn(μ , q , M , Q)}n = 0 n = ∞ which characterize the dynamics of a charged scalar field of mass μ and charge coupling constant q in the charged Reissner-Nordström black-hole spacetime of mass M and electric charge Q are determined analytically in the eikonal regime 1 ≪ Mμ < qQ. Interestingly, we find that, for a given value of the dimensionless black-hole electric charge Q / M, the imaginary part of the resonant oscillation frequency is a monotonically decreasing function of the dimensionless ratio μ / q. In particular, it is shown that the quasinormal resonance spectrum is characterized by the asymptotic behavior ℑ ω → 0 in the limiting case Mμ → qQ. This intriguing finding implies that the composed Reissner-Nordström-black-hole-charged-massive-scalar-field system is characterized by extremely long relaxation times τrelax ≡ 1 / ℑ ω → ∞ in the Mμ / qQ →1- limit.
Directory of Open Access Journals (Sweden)
Shahar Hod
2016-10-01
Full Text Available We determine the characteristic timescales associated with the linearized relaxation dynamics of the composed Reissner–Nordström-black-hole-charged-massive-scalar-field system. To that end, the quasinormal resonant frequencies {ωn(μ,q,M,Q}n=0n=∞ which characterize the dynamics of a charged scalar field of mass μ and charge coupling constant q in the charged Reissner–Nordström black-hole spacetime of mass M and electric charge Q are determined analytically in the eikonal regime 1≪Mμ
Shatskiy, A A; Lipatova, L N
2013-01-01
The free fall of electric charges and dipoles, radial and freely falling into the Schwarzschild black hole event horizon, was considered. Inverse effect of electromagnetic fields on the black hole is neglected. Dipole was considered as a point particle, so the deformation associated with exposure by tidal forces are neglected. According to the theorem, "the lack of hair" of black holes, multipole magnetic fields must be fully emitted by multipole fall into a black hole. The spectrum of electromagnetic radiation power for these multipoles (monopole and dipole) was found. Differences were found in the spectra for different orientations of the falling dipole. A general method has been developed to find radiated electromagnetic multipole fields for the free falling multipoles into a black hole (including higher order multipoles - quadrupoles, etc.). The electromagnetic spectrum can be compared with observational data from stellar mass and smaller black holes.
Critical behavior of charged Gauss-Bonnet AdS black holes in the grand canonical ensemble
Zou, De-Cheng; Wang, Bin
2014-01-01
We study the thermodynamics in the grand canonical ensemble of D-dimensional charged Gauss-Bonnet-AdS black holes in the extended phase space. We find that the usual small-large black hole phase transition, which exhibits analogy with the Van de Waals liquid-gas system holds in five-dimensional spherical charged Gauss-Bonnet-AdS black holes when its potential is fixed within the range $0<\\Phi<\\frac{\\sqrt{3}\\pi}{4}$. For the other higher dimensional and topological charged Gauss-Bonnet-AdS black holes, there is no such phase transition. In the limiting case, Reissner-Nordstrom-AdS black holes, with vanishing Gauss-Bonnet parameter, there is no critical behavior in the grand canonical ensemble. This result holds independent of the spacetime dimensions and topologies. We also examine the behavior of physical quantities in the vicinity of the critical point in the five-dimensional spherical charged Gauss-Bonnet-AdS black holes.
On the construction of charged operators inside an eternal black hole
Guica, Monica
2015-01-01
We revisit the holographic construction of (approximately) local bulk operators inside an eternal AdS black hole in terms of operators in the boundary CFTs. If the bulk operator carries charge, the construction must involve a qualitatively new object: a Wilson line that stretches between the two boundaries of the eternal black hole. This operator - more precisely, its zero mode - cannot be expressed in terms of the boundary currents and only exists in entangled states dual to two-sided geometries, which suggests that it is a state-dependent operator. We determine the action of the Wilson line on the relevant subspaces of the total Hilbert space, and show that it behaves as a local operator from the point of view of either CFT. For the case of three bulk dimensions, we give explicit expressions for the charged bulk field and the Wilson line. Furthermore, we show that when acting on the thermofield double state, the Wilson line may be extracted from a limit of certain standard CFT operator expressions. We also ...
Energy Technology Data Exchange (ETDEWEB)
Li, Jin [Chongqing University, Department of Physics, Chongqing (China); Lin, Kai [Universidade de Sao Paulo, Instituto de Fisica, CP 66318, Sao Paulo (Brazil); Yang, Nan [Huazhong University of Science and Technology, Department of Physics, Wuhan (China)
2015-03-01
Based on a regular exact black hole (BH) from nonlinear electrodynamics (NLED) coupled to general relativity, we investigate the stability of such BH through the Quasinormal Modes (QNMs) of electromagnetic (EM) field perturbations and its thermodynamics through Hawking radiation. In perturbation theory, we can deduce the effective potential from a nonlinear EM field. The comparison of the potential function between regular and RN BHs could predict similar QNMs. The QNM frequencies tell us the effect of the magnetic charge q, the overtone n, and the angular momentum number l on the dynamic evolution of NLED EM field. Furthermore we also discuss the cases of near-extreme conditions of such a magnetically charged regular BH. The corresponding QNM spectrum illuminates some special properties in the near-extreme cases. For the thermodynamics, we employ the Hamilton-Jacobi method to calculate the near-horizon Hawking temperature of the regular BH and reveal the relationship between the classical parameters of the black hole and its quantum effects. (orig.)
Charged de Sitter-like black holes: quintessence-dependent enthalpy and new extreme solutions
Azreg-Aïnou, Mustapha
2014-01-01
We consider Reissner-Nordstr\\"om black holes surrounded by quintessence where both a non-extremal event horizon and a cosmological horizon exist besides an inner horizon ($-1\\leq \\om <-1/3$). We determine new extreme black hole solutions that generalize the Nariai horizon to asymptotically de Sitter-like solutions for any order relation between the squares of the charge $q^2$ and the mass parameter $M^2$ provided $q^2$ remains smaller than some limit, which is larger than $M^2$. In the limit case $q^2=9\\om^2 M^2/(9\\om^2-1)$, we derive the general expression of the extreme cosmo-black-hole, where the three horizons merge, and discuss some of its properties. We also show that the endpoint of the evaporation process is independent of any order relation between $q^2$ and $M^2$. The Teitelboim's energy and Padmanabhan's energy are related by a nonlinear expression and are shown to correspond to different ensembles. We also determine the enthalpy $H$ of the event horizon, as well as the effective thermodynamic v...
Damped and zero-damped quasinormal modes of charged, nearly-extremal black holes
Zimmerman, Aaron
2015-01-01
Despite recent progress, the complete understanding of the perturbations of charged, rotating black holes as described by the Kerr-Newman metric remains an open and fundamental problem in relativity. In this study, we explore the existence of families of quasinormal modes of Kerr-Newman black holes whose decay rates limit to zero at extremality, called zero-damped modes in past studies. We review the nearly-extremal and WKB approximation methods for spin-weighted scalar fields (governed by the Dudley-Finley equation) and give an accounting of the regimes where scalar zero-damped and damped modes exist. Using Leaver's continued fraction method, we verify that these approximations give accurate predictions for the frequencies in their regimes of validity. In the non-rotating limit, we argue that gravito-electromagnetic perturbations of nearly-extremal Reissner-Nordstr\\"{o}m black holes have zero-damped modes in addition to the well-known spectrum of damped modes. We provide an analytic formula for the frequenci...
Numerical study of the gravitational shock wave inside a spherical charged black hole
Eilon, Ehud; Ori, Amos
2016-11-01
We numerically investigate the interior of a four-dimensional, asymptotically flat, spherically symmetric charged black hole perturbed by a scalar field Φ . Previous study by Marolf and Ori indicated that late infalling observers will encounter an effective shock wave as they approach the left portion of the inner horizon. This shock manifests itself as a sudden change in the values of various fields, within a tremendously short interval of proper time τ of the infalling observers. We confirm this prediction numerically for both test and self-gravitating scalar-field perturbations. In both cases we demonstrate the effective shock in the scalar field by exploring Φ (τ ) along a family of infalling timelike geodesics. In the self-gravitating case we also demonstrate the shock in the area coordinate r by exploring r (τ ). We confirm the theoretical prediction concerning the shock sharpening rate, which is exponential in the time of infall into the black hole. In addition we numerically probe the early stages of shock formation. We also employ a family of null (rather than timelike) ingoing geodesics to probe the shock in r . We use a finite-difference numerical code with double-null coordinates combined with a recently developed adaptive gauge method in order to solve the (Einstein+scalar ) field equations and to evolve the spacetime (and scalar field)—from the region outside the black hole down to the vicinity of the Cauchy horizon and the spacelike r =0 singularity.
Two-dimensional static black holes with pointlike sources
Melis, M
2004-01-01
We study the static black hole solutions of generalized two-dimensional dilaton-gravity theories generated by pointlike mass sources, in the hypothesis that the matter is conformally coupled. We also discuss the motion of test particles. Due to conformal coupling, these follow the geodesics of a metric obtained by rescaling the canonical metric with the dilaton.
Hod, Shahar
2016-01-01
We determine the characteristic timescales associated with the linearized relaxation dynamics of the composed Reissner-Nordstr\\"om-black-hole-charged-massive-scalar-field system. To that end, the quasinormal resonant frequencies $\\{\\omega_n(\\mu,q,M,Q)\\}_{n=0}^{n=\\infty}$ which characterize the dynamics of a charged scalar field of mass $\\mu$ and charge coupling constant $q$ in the charged Reissner-Nordstr\\"om black-hole spacetime of mass $M$ and electric charge $Q$ are determined {\\it analytically} in the eikonal regime $1\\ll M\\mu
Intersecting Non-extreme p-Branes and Linear Dilaton Background
Chen, C M; Ohta, N; Chen, Chiang-Mei; Gal'tsov, Dmitri V.; Ohta, Nobuyoshi
2005-01-01
We construct the general static solution to the supergravity action containing gravity, the dilaton and a set of antisymmetric forms describing the intersecting branes delocalized in the relative transverse dimensions. The solution is obtained by reducing the system to a set of separate Liouville equations (the intersection rules implying the separability); it contains the maximal number of free parameters corresponding to the rank of the differential equations. Imposing the requirement of the absence of naked singularities, we show that the general configurations are restricted to two and only two classes: the usual asymptotically flat intersecting branes, and the intersecting branes some of which are asymptotically flat and some approach the linear dilaton background at infinity. In both cases the configurations are black. These are supposed to be relevant for the description of the thermal phase of the QFT's in the corresponding Domain-Wall/QFT duality.
Miskovic, Olivera
2010-01-01
Motivated by possible applications within the framework of anti-de Sitter gravity/Conformal Field Theory (AdS/CFT) correspondence, charged black holes with AdS asymptotics, which are solutions to Einstein-Gauss-Bonnet gravity in D dimensions, and whose electric field is described by a nonlinear electrodynamics (NED) are studied. For a topological static black hole ansatz, the field equations are exactly solved in terms of the electromagnetic stress tensor for an arbitrary NED Lagrangian, in any dimension D and for arbitrary positive values of Gauss-Bonnet coupling. In particular, this procedure reproduces the black hole metric in Born-Infeld and conformally invariant electrodynamics previously found in the literature. Altogether, it extends to D>4 the four-dimensional solution obtained by Soleng in logarithmic electrodynamics, which comes from vacuum polarization effects. Fall-off conditions for the electromagnetic field that ensure the finiteness of the electric charge are also discussed. The black hole mass...
Institute of Scientific and Technical Information of China (English)
ZHAO Wei-Qin; LEI Jie-Hong; LIU Zhi-Xiang; YANG Shu-Zheng
2008-01-01
Extending the Parikh's quantum tunneling method of an uncharged particle, we investigate the quantum radiation characteristics of a particle with electric and magnetic charge via tunneling from the event horizon of theKerr-Newman-Kasuya black hole. The derived result supports the Parikh's opinion and the correction to the thermal spectrum is of precisely the form that satisfies the underlying unitary quantum theory, and finally provides a might explanation to the black hole information puzzle.
Area spectrum of the d-dimensional Reissner-Nordstroem black hole in the small charge limit
Energy Technology Data Exchange (ETDEWEB)
Lopez-Ortega, A, E-mail: alopezo@ipn.mx [Centro de Investigacion en Ciencia Aplicada y TecnologIa Avanzada, Unidad Legaria, Instituto Politecnico Nacional, Calzada Legaria 694, Colonia Irrigacion, Delegacion Miguel Hidalgo, Mexico, D F, C P 11500 (Mexico)
2011-02-07
A conjecture by Hod states that for the black hole horizon the spacing of its area spectrum is determined by the asymptotic value of its quasinormal frequencies. Recently to overcome some difficulties, Maggiore proposes some changes to the original Hod's conjecture. Taking into account the modifications proposed by Maggiore we calculate the area quantum of the d-dimensional Reissner-Nordstroem black hole in the small charge limit.
Energy Technology Data Exchange (ETDEWEB)
Ibohal, Ng [Department of Mathematics, Manipur University, Imphal 795003, Manipur (India)
2002-08-21
In this paper variably-charged non-rotating Reissner-Nordstrom and rotating Kerr-Newman black holes are discussed. Such a variable charge e with respect to the polar coordinate r in the field equations is referred to as an electrical radiation of the black hole. It is shown that every electrical radiation e(r) of the non-rotating black hole leads to a reduction in its mass M by some quantity. If one considers such electrical radiation taking place continuously for a long time, then a continuous reduction of the mass may take place in the black-hole body and the original mass of the black hole may be evaporated completely. At that stage, the gravity of the object may depend only on the electromagnetic field, not on the mass. Immediately after the complete evaporation of the mass, if the next radiation continues, there may be creation of a new mass leading to the formation of a negative mass naked singularity. It appears that this new mass of the naked singularity would never decrease, but might increase gradually as the radiation continues forever. A similar investigation is also discussed in the case of a variably-charged rotating Kerr-Newman black hole. Thus, it has been shown by incorporating Hawking's evaporation of radiating black holes in the form of spacetime metrics, every electrical radiation of variably-charged rotating and non-rotating black holes may produce a change in the mass of the body without affecting the Maxwell scalar.
Charge Expulsion from Black Brane Horizons, and Holographic Quantum Criticality in the Plane
D'Hoker, Eric
2012-01-01
Quantum critical behavior in 2+1 dimensions is established via holographic methods in a 5+1-dimensional Einstein gravity theory with gauge potential form fields of rank 1 and 2. These fields are coupled to one another via a tri-linear Chern-Simons term with strength k. The quantum phase transition is physically driven by the expulsion of the electric charge from inside the black brane horizon to the outside, where it gets carried by the gauge fields which acquire charge thanks to the Chern-Simons interaction. At a critical value k=k_c, zero temperature, and any finite value of the magnetic field, the IR behavior is governed by a near-horizon Lifshitz geometry. The associated dynamical scaling exponent depends on the magnetic field. For k k_c, the IR flow is towards the purely magnetic brane in AdS_6. Its near-horizon geometry is AdS_4 \\times R^2, so that the entropy density vanishes quadratically with temperature, and all charge is carried by the gauge fields outside of the horizon.
$P-V$ Criticality In the Extended Phase Space of Charged Accelerating AdS Black Holes
Liu, Hang
2016-01-01
In this paper, we investigate the $P-V$ criticality and phase transition of charged accelerating AdS black holes in the extended thermodynamic phase space in analogy between black hole system and Van der Waals liquid-gas system, where the cosmological constant $\\Lambda$ is treated as a thermodynamical variable interpreted as dynamic pressure and its conjugate quantity is the thermodynamic volume of the black holes. When the electric charge vanishes, we find that no $P-V$ criticality will appear but the Hawking-Page like phase transition will be present, just as what Schwarzschild-AdS black holes behave like. For the charged case, the $P-V$ criticality appears and the accelerating black holes will undergo a small black hole/large phase transition under the condition that the acceleration parameter $A$ and the horizon radius $r_h$ meet a certain simple relation $A r_h=a$, where $a$ is a constant in our discussion. To make $P-V$ criticality appear, there exists an upper bounds for constant $a$. When $P-V$ critic...
P-V criticality in the extended phase-space of charged accelerating AdS black holes
Liu, Hang; Meng, Xin-He
2016-11-01
In this paper, we investigate the P-V criticality and phase transition of charged accelerating AdS black holes in the extended thermodynamic phase-space in analogy between black hole system and van der Waals liquid-gas system, where the cosmological constant Λ is treated as a thermodynamical variable interpreted as dynamic pressure and its conjugate quantity is the thermodynamic volume of the black holes. When the electric charge vanishes, we find that no P-V criticality will appear but the Hawking-Page-like phase transition will be present, just as what Schwarzschild-AdS black holes behave like. For the charged case, the P-V criticality appears and the accelerating black holes will undergo a small black hole/large phase transition under the condition that the acceleration parameter A and the horizon radius rh meet a certain simple relation Arh = a, where a is a constant in our discussion. To make P-V criticality appear, there exists an upper bounds for constant a. When P-V criticality appears, we calculate the critical pressure Pc, critical temperature Tc and critical specific volume rc, and we find that Pcrc Tc is an universal number.
Information consumption by Reissner-Nordstrom black holes
Strominger, A
1993-01-01
The low-energy scattering of charged fermions by extremal magnetic Reissner-Nordstrom black holes is analyzed in the large-$N$ and $S$-wave approximations. It is shown that (in these approximations) information is carried into a causally inaccessible region of spacetime, and thereby effectively lost. It is also shown that there is an infinite degeneracy of quantum black hole ground states, or ``remnants", which store --- but will not reveal --- the information. A notable feature of the analysis --- not shared by recent analyses of dilatonic black holes --- is that the key physical questions can be answered within the weak coupling domain. We regard these results as strong evidence that effective information loss occurs in our universe.
Ehlers-harrison-type transformations in dilaton-axion gravity
Galtsov, D V
1994-01-01
The ten--parametric internal symmetry group is found in the D=4 Einstein--Maxwell--Dilaton--Axion theory restricted to space--times admitting a Killing vector field. The group includes dilaton--axion SL(2,R) duality and Harrison--type transformations which are similar to some target--space duality boosts, but act on a different set of variables. New symmetry is used to derive a seven--parametric family of rotating dilaton--axion Taub--NUT dyons.
Nashed, Gamal G. L.
2016-10-01
We have derived D-dimension rotating charged black-holes with a flat horizon in the framework of Maxwell-Weitzenböck geometry. We have discussed the singularities of these black holes using the invariants of torsion and curvature and shown that the invariants of the torsion have more singularities than those of curvature. To investigate the physics of the derived black holes we have used the Einstein-Cartan geometry to calculate the conserved quantities. From these calculations, we have analyzed the physical meaning of the constants of integration.
Konoplya, R. A.; Zhidenko, A.
2014-01-01
In our earlier work [Phys. Rev. Lett. 103, 161101 (2009)], it was shown that nonextremal highly charged Reissner-Nordstrøm-de Sitter black holes are gravitationally unstable in D>6-dimensional space-times. Here, we find accurate threshold values of the Λ term at which the instability of the extremally charged black holes starts. The larger D is, the smaller is the threshold value of Λ. We have shown that the ratio ρ =rh/rcos (where rcos and rh are the cosmological and event horizons) is proportional to e-(D -4)/2 at the onset of instability for D=7,8,…11, implying that the same law should fulfill for arbitrary D. This is numerical evidence that extremally charged Reissner-Nordstrøm-de Sitter black holes are gravitationally unstable for D>6, while asymptotically flat extremally charged Reissner-Nordstrøm black holes are stable for all D. The instability is not connected to the horizon instability discussed recently in the literature, and, unlike the later one, develops also outside the event horizon; that is, it can be seen by an external observer. In addition, for the nonextremal case through fitting of the numerical data, we obtained an approximate analytical formula which relates values of charge and the Λ term at the onset of instability.
Gußmann, Alexander
2016-01-01
The existence of classical solutions of the Einstein-Yang-Mills-Higgs equations describing black holes inside 't Hooft-Polyakov magnetic monopoles implies that not all stationary magnetically charged black holes can be uniquely described by their asymptotic characteristics. In fact, in a certain domain of parameters, there exist different spherically-symmetric, non-rotating and asymptotically-flat classical black hole solutions of the Einstein-Yang-Mills-Higgs equations which have the same ADM mass and the same magnetic charge but significantly different geometries in the near-horizon regions. (These are black hole solutions which are described by a Reissner-Nordstr\\"om metric on the one hand and the "magnetic monopole black hole solutions" which can be interpreted as black holes inside 't Hooft-Polyakov magnetic monopoles described by a metric which is not of Reissner-Nordstr\\"om form on the other hand.) One can experimentally distinguish such black holes with same asymptotic characteristics but different ne...
Newtonian Forms for Dilaton Spacetimes in String Theory
Institute of Scientific and Technical Information of China (English)
YANG Rong-Jia; JING Ji-Liang
2004-01-01
@@ We show that the Newtonian forms for the motion of particles in mechanics and for light in geometrical optics can be extend to the Gibbons-Meada and the Garfinkle-Horne dilaton spacetimes in string theory. As an example,we study the bending of the light rays, the perihelion advance of planet, and the radar echo delay in the dilaton spacetimes. The results show that the gravitational effects arising from the dilaton can be observed provided that the dilaton is large enough.
Hidden symmetries in dilaton-axion gravity
Kechkin, O V
1996-01-01
Four--dimensional Einstein--Maxwell--dilaton--axion system restricted to space--times with one non--null Killing symmetry is formulated as the three--dimensional gravity coupled sigma--model. Several alternative representations are discussed and the associated hidden symmetries are revealed. The action of target space isometries on the initial set of (non--dualized ) variables is found. New mulicenter solutions are obtained via generating technique based on the formulation in terms of the non--dualized variables.
Cosmological Constraints on Higgs-Dilaton Inflation
Trashorras, Manuel; Garcia-Bellido, Juan
2016-01-01
We test the viability of the Higgs-Dilaton Model (HDM) compared to the cosmological constant ($\\Lambda$CDM) and evolving dark energy ($w_0 w_a$CDM) models, by using the latest cosmological data that includes the Cosmic Microwave Background temperature, polarization and lensing data from the Planck satellite (2015 release), the BICEP and Keck Array experiments, the Type Ia supernovae from the JLA catalog, the Baryon Acoustic Oscillations and finally, the Weak Lensing data from the CFHTLenS survey. We find that the values of all cosmological parameters allowed by the Higgs-Dilaton model Inflation are well within the \\textit{Planck 15} constraints. In particular, we have that $w_0 = -1.0001^{+0.0072}_{-0.0074}$, $w_a = 0.00^{+0.15}_{-0.16}$, $n_s = 0.9693^{+0.0083}_{-0.0082}$, $\\alpha_s = -0.001^{+0.013}_{-0.014}$ and $r_{0.05} = 0.0025^{+0.0017}_{-0.0016}$ (95\\%C.L.). We also place new stringent constraints on the couplings of the Higgs-Dilaton model and we find that $\\xi_\\chi < 0.00328$ and $\\xi_h/\\sqrt{\\la...
Remark on the dilaton mass relation
Kasai, Aya; Suzuki, Hiroshi
2016-01-01
Recently, Golterman and Shamir presented an effective field theory which is supposed to describe the low-energy physics of the pion and the dilaton in an $SU(N_c)$ gauge theory with $N_f$ Dirac fermions in the fundamental representation. By employing this formulation with a slight but important modification, we derive a relation between the dilaton mass squared~$m_\\tau^2$, with and without the fermion mass~$m$, and the pion mass squared~$m_\\pi^2$ to the leading order of the chiral logarithm. This is analogous to a similar relation obtained by Matsuzaki and~Yamawaki on the basis of a somewhat different low-energy effective field theory. Our relation reads $m_\\tau^2=m_\\tau^2|_{m=0}+KN_f\\Hat{f}_\\pi^2m_\\pi^2/(2\\Hat{f}_\\tau^2)+O(m_\\pi^4\\ln m_\\pi^2)$ with~$K=9$, where $\\Hat{f}_\\pi$ and~$\\Hat{f}_\\tau$ are decay constants of the pion and the dilaton, respectively. This mass relation differs from the one derived by Matsuzaki and~Yamawaki on the points that $K=(3-\\gamma_m)(1+\\gamma_m)$, where $\\gamma_m$ is the mass ano...
Directory of Open Access Journals (Sweden)
Amin Dehyadegari
2017-05-01
Full Text Available It has been argued that charged Anti-de Sitter (AdS black holes have similar thermodynamic behavior as the Van der Waals fluid system, provided one treats the cosmological constant as a thermodynamic variable (pressure in an extended phase space. In this paper, we disclose the deep connection between charged AdS black holes and Van der Waals fluid system from an alternative point of view. We consider the mass of an AdS black hole as a function of square of the charge Q2 instead of the standard Q, i.e. M=M(S,Q2,P. We first justify such a change of view mathematically and then ask if a phase transition can occur as a function of Q2 for fixed P. Therefore, we write the equation of state as Q2=Q2(T,Ψ where Ψ (conjugate of Q2 is the inverse of the specific volume, Ψ=1/v. This allows us to complete the analogy of charged AdS black holes with Van der Waals fluid system and derive the phase transition as well as critical exponents of the system. We identify a thermodynamic instability in this new picture with real analogy to Van der Waals fluid with physically relevant Maxwell construction. We therefore study the critical behavior of isotherms in Q2–Ψ diagram and deduce all the critical exponents of the system and determine that the system exhibits a small–large black hole phase transition at the critical point (Tc,Qc2,Ψc. This alternative view is important as one can imagine such a change for a given single black hole i.e. acquiring charge which induces the phase transition. Finally, we disclose the microscopic properties of charged AdS black holes by using thermodynamic geometry. Interestingly, we find that scalar curvature has a gap between small and large black holes, and this gap becomes exceedingly large as one moves away from the critical point along the transition line. Therefore, we are able to attribute the sudden enlargement of the black hole to the strong repulsive nature of the internal constituents at the phase transition.
Zakharov, Alexander F
2014-01-01
Using an algebraic condition of vanishing discriminant for multiple roots of fourth degree polynomials we derive an analytical expression of a shadow size as a function of a charge in the Reissner -- Nordstr\\"om (RN) metric \\cite{Reissner_16,Nordstrom_18}. We consider shadows for negative tidal charges and charges corresponding to naked singularities $q=\\mathcal{Q}^2/M^2 > 1$, where $\\mathcal{Q}$ and $M$ are black hole charge and mass, respectively, with the derived expression. An introduction of a negative tidal charge $q$ can describe black hole solutions in theories with extra dimensions, so following the approach we consider an opportunity to extend RN metric to negative $\\mathcal{Q}^2$, while for the standard RN metric $\\mathcal{Q}^2$ is always non-negative. We found that for $q > 9/8$ black hole shadows disappear. Significant tidal charges $q=-6.4$ (suggested by Bin-Nun (2010)) are not consistent with observations of a minimal spot size at the Galactic Center observed in mm-band, moreover, these observa...
Numerical study of the gravitational shock wave inside a spherical charged black hole
Eilon, Ehud
2016-01-01
We numerically investigate the interior of a four-dimensional, asymptotically flat, spherically symmetric charged black hole perturbed by a scalar field $\\Phi$. Previous study by Marolf and Ori indicated that late infalling observers will encounter an effective shock wave as they approach the left portion of the inner horizon. This shock manifests itself as a sudden change in the values of various fields, within a tremendously short interval of proper time $\\tau$ of the infalling observers. We confirm this prediction numerically for both test and self-gravitating scalar field perturbations. In both cases we demonstrate the effective shock in the scalar field by exploring $\\Phi(\\tau)$ along a family of infalling timelike geodesics. In the self-gravitating case we also demonstrate the shock in the area coordinate $r$ by exploring $r(\\tau)$. We confirm the theoretical prediction concerning the shock sharpening rate, which is exponential in the time of infall into the black hole. In addition we numerically probe ...
The self-force on a non-minimally coupled static scalar charge outside a Schwarzschild black hole
Energy Technology Data Exchange (ETDEWEB)
Cho, Demian H J; Tsokaros, Antonios A; Wiseman, Alan G [Department of Physics, University of Wisconsin-Milwaukee, PO Box 413, Milwaukee, WI 53201 (United States)
2007-03-07
The finite part of the self-force on a static, non-minimally coupled scalar test charge outside a Schwarzschild black hole is zero. This result is determined from the work required to slowly raise or lower the charge through an infinitesimal distance. Unlike similar force calculations for minimally-coupled scalar charges or electric charges, we find that we must account for a flux of field energy that passes through the horizon and changes the mass and area of the black hole when the charge is displaced. This occurs even for an arbitrarily slow displacement of the non-minimally coupled scalar charge. For a positive coupling constant, the area of the hole increases when the charge is lowered and decreases when the charge is raised. The fact that the self-force vanishes for a static, non-minimally coupled scalar charge in Schwarzschild spacetime agrees with a simple prediction of the Quinn-Wald axioms. However, Zel'nikov and Frolov computed a non-vanishing self-force for a non-minimally coupled charge. Our method of calculation closely parallels the derivation of Zel'nikov and Frolov, and we show that their omission of this unusual flux is responsible for their (incorrect) result. When the flux is accounted for, the self-force vanishes. This correction eliminates a potential counter example to the Quinn-Wald axioms. The fact that the area of the black hole changes when the charge is displaced brings up two interesting questions that did not arise in similar calculations for static electric charges and minimally coupled scalar charges. (1) How can we reconcile a decrease in the area of the black hole horizon with the area theorem which concludes that {delta}Area{sub horizon} {>=} 0? The key hypothesis of the area theorem is that the stress-energy tensor must satisfy a null-energy condition T{sup {alpha}}{sup {beta}}l{sub {alpha}}l{sub {beta}} {>=} 0 for any null vector l{sub {alpha}}. We explicitly show that the stress-energy associated with a non
Curved dilatonic brane-worlds and the cosmological constant problem
Alonso-Alberca, N; Silva, P J; Alonso-Alberca, Natxo; Janssen, Bert; Silva, Pedro J.
2000-01-01
We construct a model for dilatonic brane worlds with constant curvature on the brane, i.e. a non-zero four-dimensional cosmological constant, given in function of the dilaton coupling and the cosmological constant of the bulk. It is shown that the brane cosmological constant does not change under quantum fluctuations in the brane tension.
Mechanics of Apparent Horizon in Two Dimensional Dilaton Gravity
Cai, Rong-Gen
2016-01-01
In this article, we give a definition of apparent horizon in a two dimensional general dilaton gravity theory. With this definition, we construct the mechanics of the apparent horizon by introducing a quasi-local energy of the theory. Our discussion generalizes the apparent horizons mechanics in general spherically symmetric spactimes in four or higher dimensions to the two dimensional dilaton gravity case.
ADM mass of the quantum-corrected Schwarzchild black hole
Buric, M; Buric, Maja; Radovanovic, Voja
2000-01-01
We study the hamiltonian and constraints of spherically symmetric dilaton gravity model. We find the ADM mass of the solution representing the Schwarzchild black hole in thermal equilibrium with the Hawking radiation.
Applications of gauge/gravity dualities with charged Anti-de Sitter black holes
Energy Technology Data Exchange (ETDEWEB)
Grass, Viviane Theresa
2010-05-17
In this thesis, we deal with different applications of the Anti-de Sitter/Conformal Field Theory (AdS/CFT) correspondence. The AdS/CFT correspondence, which is also more generally referred to as gauge/gravity duality, is a conjectured duality in superstring theory between strongly-coupled four-dimensional N=4 superconformal Yang-Mills theory and weakly-coupled type IIB string theory in five-dimensional AdS spacetime. This duality provides a powerful method to investigate strongly-coupled low-energy systems in four dimensions by substitutionally carrying out calculations in five-dimensional weakly-coupled supergravity. In this work, we use the AdS/CFT correspondence to explore three different strongly-coupled systems, namely a brane world accommodating a strongly-coupled field theory, a strongly-coupled fluid on a three-sphere and a strongly-coupled p-wave superfluid. In all these cases, the dual supergravity descriptions involve charged AdS black holes. The first system studied here is a Randall-Sundrum brane world moving in the background of a five-dimensional non-extremal black hole of N=2 gauged supergravity. The equations of motion of the brane are found to be equal to the Friedmann-Robertson-Walker (FRW) equations for a closed universe. The closed brane universe has special thermodynamic properties. The energy of the brane field theory exhibits a subextensive Casimir contribution, and the entropy can be expressed as a Cardy-Verlinde-type formula. We show that the equations for both quantities can take forms that strongly resemble the two FRW equations. At the horizon of the black hole, these two sets of equations are shown to even merge with each other which might suggest the existence of a common underlying theory. In addition, as a by-product result, the non-extremal black hole solutions considered here are found to admit an alternative description in terms of first-order flow equations similar to those which are well-known from the attractor mechanism of
Techni-dilaton at Conformal Edge
Hashimoto, Michio
2010-01-01
Techni-dilaton (TD) was proposed long ago in the technicolor (TC) near criticality/conformality. To reveal the critical behavior of TD, we explicitly compute the nonperturbative contributions to the scale anomaly $$ and to the techni-gluon condensate $$, which are generated by the dynamical mass m of the techni-fermions. Our computation is based on the (improved) ladder Schwinger-Dyson equation, with the gauge coupling $\\alpha$ replaced by the two-loop running one $\\alpha(\\mu)$ having the Caswell-Banks-Zaks IR fixed point $\\alpha_*$: $\\alpha(\\mu) \\simeq \\alpha = \\alpha_*$ for the IR region $m /m^4\\to const \
Confronting Dilaton-exchange gravity with experiments
Klapdor-Kleingrothaus, H V; Sarkar, U
2000-01-01
We study the experimental constraints on theories, where the equivalence principle is violated by dilaton-exchange contributions to the usual graviton-exchange gravity. We point out that in this case it is not possible to have any CPT violation and hence there is no constraint from the CPT violating measurements in the $K-$system. The most stringent bound is obtained from the $K_L - K_S$ mass difference. In contrast, neither neutrino oscillation experiments nor neutrinoless double beta decay imply significant constraints.
Analytic treatment of the system of a Kerr-Newman black hole and a charged massive scalar field
Hod, Shahar
2016-01-01
Charged rotating Kerr-Newman black holes are known to be superradiantly unstable to perturbations of charged massive bosonic fields whose proper frequencies lie in the bounded regime $0 < \\omega < \\text{min} \\{\\omega_{\\text{c}} \\equiv m \\Omega_{\\text{H}} + q\\Phi_{\\text{H}},\\mu\\}$ [here $\\{\\Omega_{\\text{H}}, \\Phi_{\\text{H}}\\}$ are respectively the angular velocity and electric potential of the Kerr-Newman black hole, and $\\{m,q,\\mu\\}$ are respectively the azimuthal harmonic index, the charge coupling constant, and the proper mass of the field]. In this paper we study analytically the complex resonance spectrum which characterizes the dynamics of linearized charged massive scalar fields in a near-extremal Kerr-Newman black-hole spacetime. Interestingly, it is shown that near the critical frequency $\\omega_{\\text{c}}$ for superradiant amplification and in the eikonal large-mass regime, the superradiant instability growth rates of the explosive scalar fields are characterized by a non-trivial (non-monotonic...
Jusufi, Kimet
2016-01-01
In this paper we study the quantum tunneling of charged and magnetized particles (magnetic monopoles) from the global monopole black hole by incorporating the quantum gravity effects. Starting from the modified Maxwell's equations and Generalized Uncertainty Relation (GUP), we recover the GUP corrected temperate for the global monopole black hole by solving the modified Dirac equation via Hamilton-Jacobi method. Furthermore, we also include the quantum corrections beyond the semiclassical approximation, in particular, first we find the logarithmic corrections of GUP corrected entropy and finally we calculate the GUP corrected specific heat capacity.
Institute of Scientific and Technical Information of China (English)
ZHANG Hong-Bao; CAO Zhou-Jian; GAO Chong-Shou
2004-01-01
Si-Jie Gao has recently investigated Hawking radiation from spherically symmetrical gravitational collapse to an extremal R-N black hole for a real scalar field. Especially he estimated the upper bound for the expected number of particles in any wave packet belonging to Hout spontaneously produced from the state |0＞in, which confirms the traditional belief that extremal black holes do not radiate particles. Making some modifications, we demonstrate that the analysis can go through for a charged scalar field.
Directory of Open Access Journals (Sweden)
Shahar Hod
2015-07-01
Full Text Available The quasinormal resonance spectrum {ωn(μ,q,M,Q}n=0n=∞ of charged massive scalar fields in the charged Reissner–Nordström black-hole spacetime is studied analytically in the large-coupling regime qQ≫Mμ (here {μ,q} are respectively the mass and charge coupling constant of the field, and {M,Q} are respectively the mass and electric charge of the black hole. This physical system provides a striking illustration for the validity of the universal relaxation bound τ×T≥ħ/π in black-hole physics (here τ≡1/ℑω0 is the characteristic relaxation time of the composed black-hole-scalar-field system, and T is the Bekenstein–Hawking temperature of the black hole. In particular, it is shown that the relaxation dynamics of charged massive scalar fields in the charged Reissner–Nordström black-hole spacetime may saturate this quantum time-times-temperature inequality. Interestingly, we prove that potential violations of the bound by light scalar fields are excluded by the Schwinger-type pair-production mechanism (a vacuum polarization effect, a quantum phenomenon which restricts the physical parameters of the composed black-hole-charged-field system to the regime qQ≪M2μ2/ħ.
Supermassive screwed cosmic string in dilaton gravity
Energy Technology Data Exchange (ETDEWEB)
Bezerra, V B [Departamento de Fisica, Universidade Federal da ParaIba, 58059-970, Joao Pessoa, PB (Brazil); Ferreira, Cristine N [Nucleo de Fisica, Centro Federal de Educacao Tecnologica de Campos, Rua Dr Siqueira, 273-Parque Dom Bosco, 28030-130, Campos dos Goytacazes, RJ (Brazil); Cuesta, H J Mosquera [Instituto de Cosmologia, Relatividade e AstrofIsica (ICRA-BR), Centro Brasileiro de Pesquisas Fisicas, Rua Dr Xavier Sigaud 150, Urca 22290-180, Rio de Janeiro, RJ (Brazil)
2006-06-21
The early universe might have undergone phase transitions at energy scales much higher than the one corresponding to the grand unified theories (GUT) scales. At these higher energy scales, the transition at which gravity separated from all other interactions, the so-called Planck era, more massive strings called supermassive cosmic strings could have been produced, with energy of about 10{sup 19} GeV. The dynamics of strings formed with this energy scale cannot be described by means of the weak-field approximation, as in the standard procedure for ordinary GUT cosmic strings. As suggested by string theories, at this extreme energy, gravity may be transmitted by some kind of scalar field (usually called the dilaton) in addition to the tensor field of Einstein's theory of gravity. It is then permissible to tackle the issue regarding the dynamics of supermassive cosmic strings within this framework. With this aim, we obtain the gravitational field of a supermassive screwed cosmic string in a scalar-tensor theory of gravity. We show that for the supermassive configuration, exact solutions of scalar-tensor screwed cosmic strings can be found in connection with the Bogomol'nyi limit. We show that the generalization of Bogomol'nyi arguments to the Brans-Dicke theory is possible when torsion is present and we obtain an exact solution in this supermassive regime, with the dilaton solution obtained by consistency with internal constraints.
Zhang, Bing
2016-08-01
The discoveries of GW150914, GW151226, and LVT151012 suggest that double black hole (BH-BH) mergers are common in the universe. If at least one of the two merging black holes (BHs) carries a certain amount of charge, possibly retained by a rotating magnetosphere, the inspiral of a BH-BH system would drive a global magnetic dipole normal to the orbital plane. The rapidly evolving magnetic moment during the merging process would drive a Poynting flux with an increasing wind power. The magnetospheric activities during the final phase of the merger would make a fast radio burst (FRB) if the BH charge can be as large as a factor of \\hat{q}˜ ({10}-9{--}{10}-8) of the critical charge Q c of the BH. At large radii, dissipation of the Poynting flux energy in the outflow would power a short-duration high-energy transient, which would appear as a detectable short-duration gamma-ray burst (GRB) if the charge can be as large as \\hat{q}˜ ({10}-5{--}{10}-4). The putative short GRB coincident with GW150914 recorded by Fermi GBM may be interpreted with this model. Future joint GW/GRB/FRB searches would lead to a measurement or place a constraint on the charges carried by isolate BHs.
Setare, M. R.; Adami, H.
2016-01-01
In the first order formalism of gravity theories, there are some theories which are not Lorentz-diffeomorphism covariant. In the framework of such theories we cannot apply the method of conserved charge calculation used in Lorentz-diffeomorphism covariant theories. In this paper we firstly introduce the total variation of a quantity due to an infinitesimal Lorentz-diffeomorphism transformation. Secondly, in order to obtain the conserved charges of Lorentz-diffeomorphism non-covariant theories, we extend the Tachikawa method [1]. This extension includes not only Lorentz gauge transformation but also the diffeomorphism. We apply this method to the Chern-Simons-like theories of gravity (CSLTG) and obtain a general formula for the entropy of black holes in those theories. Finally, some examples on CSLTG are provided and the entropy of the BTZ black hole is calculated in the context of the examples.
Directory of Open Access Journals (Sweden)
M.R. Setare
2016-01-01
Full Text Available In the first order formalism of gravity theories, there are some theories which are not Lorentz-diffeomorphism covariant. In the framework of such theories we cannot apply the method of conserved charge calculation used in Lorentz-diffeomorphism covariant theories. In this paper we firstly introduce the total variation of a quantity due to an infinitesimal Lorentz-diffeomorphism transformation. Secondly, in order to obtain the conserved charges of Lorentz-diffeomorphism non-covariant theories, we extend the Tachikawa method [1]. This extension includes not only Lorentz gauge transformation but also the diffeomorphism. We apply this method to the Chern–Simons-like theories of gravity (CSLTG and obtain a general formula for the entropy of black holes in those theories. Finally, some examples on CSLTG are provided and the entropy of the BTZ black hole is calculated in the context of the examples.
Energy Technology Data Exchange (ETDEWEB)
Setare, M.R., E-mail: rezakord@ipm.ir; Adami, H., E-mail: hamed.adami@yahoo.com
2016-01-15
In the first order formalism of gravity theories, there are some theories which are not Lorentz-diffeomorphism covariant. In the framework of such theories we cannot apply the method of conserved charge calculation used in Lorentz-diffeomorphism covariant theories. In this paper we firstly introduce the total variation of a quantity due to an infinitesimal Lorentz-diffeomorphism transformation. Secondly, in order to obtain the conserved charges of Lorentz-diffeomorphism non-covariant theories, we extend the Tachikawa method [1]. This extension includes not only Lorentz gauge transformation but also the diffeomorphism. We apply this method to the Chern–Simons-like theories of gravity (CSLTG) and obtain a general formula for the entropy of black holes in those theories. Finally, some examples on CSLTG are provided and the entropy of the BTZ black hole is calculated in the context of the examples.
Setare, M R
2016-01-01
In the first order formalism of gravity theories, may be exist some theories which are not Lorentz-difeomorphism covariant so for such theories a method for which one can calculate conserved charges of Lorentz-difeomorphism covariant theories are useless. In this letter we introduce the total variation of a quantity due to an infinitesimal Lorentz-diffeomorphism transformation. Then using this concept, in order to obtain the conserved charges in Lorentz-diffeomorphism non-covariant theories, we extend the Tachikawa's method \\cite{3} so that it includes Lorentz gauge transformation in addition to diffeomorphism. We apply this method on the Chern-Simons-like theories of gravity and we find out a general formula for the entropy of black holes in those theories. Eventually, we consider some examples and calculate entropy of the BTZ black hole in the context of this examples.
Tursunov, Arman; Kološ, Martin
2016-01-01
We study motion of charged particles in the field of a rotating black hole immersed into an external asymptotically uniform magnetic field, focusing on the epicyclic quasi-circular orbits near the equatorial plane. Separating the circular orbits into four qualitatively different classes according to the sign of the canonical angular momentum of the motion and the orientation of the Lorentz force, we analyse the circular orbits using the so called force formalism. We find the analytical solutions for the radial profiles of velocity, specific angular momentum and specific energy of the circular orbits in dependence on the black hole dimensionless spin and the magnetic field strength. The innermost stable circular orbits are determined for all four classes of the circular orbits. The stable circular orbits with outward oriented Lorentz force can extend to radii lower than the radius of the corresponding photon circular geodesic. We calculate the frequencies of the harmonic oscillatory motion of the charged parti...
More on the dilatonic Einstein-Gauss-Bonnet gravity
Iihoshi, Masao
2010-01-01
Einstein-Gauss-Bonnet gravity coupled to a dynamical dilaton is examined from the viewpoint of Einstein's equivalence principle. We point out that the usual frame change that applies to the action without curvature correction does not cure the problem of nonminimal couplings by the dynamical nature of a dilaton field. Thus a modification of the Einstein frame is required. It is proposed that the kinetic term of a dilaton should be brought to a canonical form, which completely fixes the additional terms associated with the frame transformation.
Light dilaton in the large N tricritical O (N ) model
Omid, Hamid; Semenoff, Gordon W.; Wijewardhana, L. C. R.
2016-12-01
The leading order of the large N limit of the O (N ) symmetric phi-six theory in three dimensions has a phase which exhibits spontaneous breaking of scale symmetry accompanied by a massless dilaton which is a Goldstone boson. At the next-to-leading order in large N , the phi-six coupling has a beta function of order 1 /N and it is expected that the dilaton acquires a small mass, proportional to the beta function and the condensate. In this article, we show that this "light dilaton" is actually a tachyon. This indicates an instability of the phase of the theory with spontaneously broken approximate scale invariance.
Dilaton Stabilization in Three-generation Heterotic String Model
Beye, Florian; Kuwakino, Shogo
2016-01-01
We study dilaton stabilization in heterotic string models. By utilizing the asymmetric orbifold construction, we construct an explicit three-generation model whose matter content in the visible sector is the supersymmetric standard model with additional vectorlike matter. This model does not contain any geometric moduli fields except the dilaton field. Model building at a symmetry enhancement point in moduli space enlarges the rank of the hidden gauge group. By analyzing multiple hidden gauge sectors, the dilaton field is stabilized by the racetrack mechanism. We also discuss a supersymmetry breaking scenario and F-term uplifting.
Dilaton stabilization in three-generation heterotic string model
Directory of Open Access Journals (Sweden)
Florian Beye
2016-09-01
Full Text Available We study dilaton stabilization in heterotic string models. By utilizing the asymmetric orbifold construction, we construct an explicit three-generation model whose matter content in the visible sector is the supersymmetric standard model with additional vectorlike matter. This model does not contain any geometric moduli fields except the dilaton field. Model building at a symmetry enhancement point in moduli space enlarges the rank of the hidden gauge group. By analyzing multiple hidden gauge sectors, the dilaton field is stabilized by the racetrack mechanism. We also discuss a supersymmetry breaking scenario and F-term uplifting.
Dilaton stabilization in three-generation heterotic string model
Beye, Florian; Kobayashi, Tatsuo; Kuwakino, Shogo
2016-09-01
We study dilaton stabilization in heterotic string models. By utilizing the asymmetric orbifold construction, we construct an explicit three-generation model whose matter content in the visible sector is the supersymmetric standard model with additional vectorlike matter. This model does not contain any geometric moduli fields except the dilaton field. Model building at a symmetry enhancement point in moduli space enlarges the rank of the hidden gauge group. By analyzing multiple hidden gauge sectors, the dilaton field is stabilized by the racetrack mechanism. We also discuss a supersymmetry breaking scenario and F-term uplifting.
Light dilatons in warped space: Higgs boson and LHCb anomalies
Megias, Eugenio; Pujolas, Oriol; Quiros, Mariano
2016-01-01
We study the extension of the Standard Model (SM) with a light dilaton in a five dimensional warped model. In particular, we analyze the coupling of the dilaton with the SM matter fields, compare the model predictions with Electroweak Precisions Tests and find the corresponding bounds on the mass of the lightest Kaluza-Klein modes. We also investigate the possibility that the Higgs-like resonance found at the LHC can be a dilaton. Finally, we show that our set-up can also provide an explanation of the anomalies recently observed in $B$-meson decays.
Soroushfar, Saheb; Kazempour, Sobhan; Grunau, Saskia; Kunz, Jutta
2016-01-01
We study the geodesic equations in the space time of a rotating charged black hole in $f(R)$ gravity. We derive the equations of motion for test particles and light rays and present their solutions in terms of the Weierstrass $\\wp$, $\\zeta$ and $\\sigma$ functions as well as the Kleinian $\\sigma$ function. With the help of parametric diagrams and effective potentials we analyze the geodesic motion and classify the possible orbit types.
On the critical phenomena and thermodynamic geometry of charged Gauss-Bonnet AdS black hole
Wei, Shao-Wen
2012-01-01
In this paper, we study the phase structure and equilibrium state space geometry of charged topological Gauss-Bonnet black holes in $d$-dimensional anti-de Sitter spacetime. Serval critical points are obtained in the canonical ensemble, and the critical phenomena and critical exponents near them are examined. We find that the phase structures and critical phenomena drastically depend on the cosmological constant $\\Lambda$ and dimensionality $d$. The result also shows that there exists an analogy between the black hole and the van der Waals liquid gas system. Moreover, we explore the phase transition and possible property of the microstructure using the state space geometry. It is found that the Ruppeiner curvature diverges exactly at the points where the heat capacity at constant charge of the black hole diverges. This black hole is also found to be a multiple system, i.e., it is similar to the ideal gas of fermions in some range of the parameters, while to the ideal gas of bosons in another range.
Mišković, Olivera; Olea, Rodrigo
2011-01-01
Motivated by possible applications within the framework of anti-de Sitter gravity/conformal field theory correspondence, charged black holes with AdS asymptotics, which are solutions to Einstein-Gauss-Bonnet gravity in D dimensions, and whose electric field is described by nonlinear electrodynamics are studied. For a topological static black hole ansatz, the field equations are exactly solved in terms of the electromagnetic stress tensor for an arbitrary nonlinear electrodynamic Lagrangian in any dimension D and for arbitrary positive values of Gauss-Bonnet coupling. In particular, this procedure reproduces the black hole metric in Born-Infeld and conformally invariant electrodynamics previously found in the literature. Altogether, it extends to D>4 the four-dimensional solution obtained by Soleng in logarithmic electrodynamics, which comes from vacuum polarization effects. Falloff conditions for the electromagnetic field that ensure the finiteness of the electric charge are also discussed. The black hole mass and vacuum energy as conserved quantities associated to an asymptotic timelike Killing vector are computed using a background-independent regularization of the gravitational action based on the addition of counterterms which are a given polynomial in the intrinsic and extrinsic curvatures.
On thermodynamics of charged AdS black holes in extended phases space via M2-branes background
Energy Technology Data Exchange (ETDEWEB)
Chabab, M.; Masmar, K. [Cadi Ayyad University, High Energy Physics and Astrophysics Laboratory, FSSM, Marrakesh (Morocco); El Moumni, H. [Cadi Ayyad University, High Energy Physics and Astrophysics Laboratory, FSSM, Marrakesh (Morocco); Universite Ibn Zohr, Departement de Physique, Faculte des Sciences, Agadir (Morocco)
2016-06-15
Motivated by a recent work on asymptotically AdS{sub 4} black holes in M-theory, we investigate both thermodynamics and the thermodynamical geometry of Reissner-Nordstrom-AdS black holes from M2-branes. More precisely, we study AdS black holes in AdS{sub 4} x S{sup 7}, with the number of M2-branes interpreted as a thermodynamical variable. In this context, we calculate various thermodynamical quantities including the chemical potential, and examine their phase transitions along with the corresponding stability behaviors. In addition, we also evaluate the thermodynamical curvatures of the Weinhold, Ruppeiner, and Quevedo metrics for M2-branes geometry to study the stability of such a black object. We show that the singularities of these scalar curvature's metrics reproduce similar stability results to those obtained by the phase transition diagram via the heat capacities in different ensembles either when the number of the M2 branes or the charge is held fixed. Also, we note that all results derived in Belhaj et al. (Eur Phys J C 76(2):73, 2016) are recovered in the limit of the vanishing charge. (orig.)
Canonical structure of 2D black holes
Navarro-Salas, J; Talavera, C F
1994-01-01
We determine the canonical structure of two-dimensional black-hole solutions arising in $2D$ dilaton gravity. By choosing the Cauchy surface appropriately we find that the canonically conjugate variable to the black hole mass is given by the difference of local (Schwarzschild) time translations at right and left spatial infinities. This can be regarded as a generalization of Birkhoff's theorem.
Proposal for a geophysical search for dilatonic waves
Shiomi, Sachie
2008-01-01
We propose a new method of searching for the composition-dependent dilatonic waves, predicted by unified theories of strings. In this method, Earth's surface-gravity changes due to translational motions of its inner core, excited by dilatonic waves, are searched for by using superconducting gravimeters. This method has its best sensitivity at the frequency of $\\sim$ 7 $\\times$ 10$^{-5}$ Hz, which is lower than the sensitive frequencies of previous proposals using gravitational-wave detectors: $\\sim$ 10 to 1000 Hz. Using available results of surface-gravity measurements with superconducting gravimeters and assuming a simple Earth model, we present preliminary upper limits on the energy density of a stochastic background of massless dilatons at the low frequency. Though the results are currently limited by the uncertainty in the Earth model, this method has a potential of detecting dilatonic waves in a new window.
Trova, A.; Karas, V.; Slaný, P.; Kovář, J.
2016-09-01
We present an analytical approach for the equilibrium of a self-gravitating charged fluid embedded in a spherical gravitational and dipolar magnetic fields produced by a central mass. Our scheme is proposed, as a toy model, in the context of gaseous/dusty tori surrounding supermassive black holes in galactic nuclei. While the central black hole dominates the gravitational field and remains electrically neutral, the surrounding material has a non-negligible self-gravitational effect on the torus structure. By charging mechanisms it also acquires non-zero electric charge density, so the two influences need to be taken into account to achieve a self-consistent picture. Using our approach we discuss the impact of self-gravity, represented by the term {d}{{t}} (ratio of the torus total mass to the mass of the central body), on the conditions for existence of the equilibrium and the morphology and typology of the tori. By comparison with a previous work without self-gravity, we show that the conditions can be different. Although the main aim of the present paper is to discuss a framework for the classification of electrically charged, magnetized, self-gravitating tori, we also mention potential astrophysical applications to vertically stratified fluid configurations.
Cosmological model in 2d dilaton gravity
Mishima, T; Mishima, Takashi; Nakamichi, Akika
1993-01-01
We apply CGHS-type dilaton gravity model to (1+1)-dimensional cosmological situations. First the behavior of a compact 1-dimensional universe (i.e. like a closed string) is classified on the assumption of homogeneity of universe. Several interesting solutions are found, which include a Misner-type universe having closed time-like curves, and an asymptotically de Sitter universe first pointed out by Yoshimura. In the second half of this talk, we discuss the modification of the classical homogeneous solutions, considering inhomogeneity of classical conformal matters and also quantum back-reaction respectively. (An expanded version of the talk presented by T. Mishima at Yukawa Institute of Theoretical Physics workshop `Quantum Gravity' 24-27, November 1992.)
Singularity-free interaction in dilaton-Maxwell electrodynamics
Kechkin, O. V.; Mosharev, P. A.
2016-09-01
An effective potential is created for the dynamics of a test particle, which preserves dilatation symmetry for nonlinear static dilaton-Maxwell background. It is found that the central interaction in this theory is singularity-free everywhere; it vanishes at short distances and demonstrates Coulomb behavior far from the source. It is shown that static and spherically symmetric source behaves like a soliton: it has the finite energy characteristics that are inversely proportional to the dilaton-Maxwell coupling constant.
Class of Einstein-Maxwell-Dilaton-Axion Space-Times
2009-01-01
We use the harmonic maps ansatz to find exact solutions of the Einstein-Maxwell-Dilaton-Axion (EMDA) equations. The solutions are harmonic maps invariant to the symplectic real group in four dimensions $Sp(4,\\Rreal)\\sim O(5)$. We find solutions of the EMDA field equations for the one and two dimensional subspaces of the symplectic group. Specially, for illustration of the method, we find space-times that generalise the Schwarzschild solution with dilaton, axion and electromagnetic fields.
Nonlinear Structure Formation with the Environmentally Dependent Dilaton
Brax, Phil; Davis, Anne-C; Li, Baojiu; Shaw, Douglas J
2011-01-01
We have studied the nonlinear structure formation of the environmentally dependent dilaton model using $N$-body simulations. We find that the mechanism of suppressing the scalar fifth force in high-density regions works very well. Within the parameter space allowed by the solar system tests, the dilaton model predicts small deviations of the matter power spectrum and the mass function from their $\\Lambda$CDM counterparts. The importance of taking full account of the nonlinearity of the model is also emphasized.
Institute of Scientific and Technical Information of China (English)
Li Hui-Ling
2011-01-01
This paper is devoted to the investigation the fermion tunneling radiation of squashed black holes in the Godel universe and charged Kaluza-Klein space-time. For black holes with different dimensions, establishing a set of appropriate matrices γμ for the general covariant Dirac equation plays an important role in the semi-classical tunneling method. By constructing two sets of γμ matrices, we have successfully derived the tunneling probability and Hawking temperature of the black holes.
Information retrieval from black holes
Lochan, Kinjalk; Chakraborty, Sumanta; Padmanabhan, T.
2016-08-01
It is generally believed that, when matter collapses to form a black hole, the complete information about the initial state of the matter cannot be retrieved by future asymptotic observers, through local measurements. This is contrary to the expectation from a unitary evolution in quantum theory and leads to (a version of) the black hole information paradox. Classically, nothing else, apart from mass, charge, and angular momentum is expected to be revealed to such asymptotic observers after the formation of a black hole. Semiclassically, black holes evaporate after their formation through the Hawking radiation. The dominant part of the radiation is expected to be thermal and hence one cannot know anything about the initial data from the resultant radiation. However, there can be sources of distortions which make the radiation nonthermal. Although the distortions are not strong enough to make the evolution unitary, these distortions carry some part of information regarding the in-state. In this work, we show how one can decipher the information about the in-state of the field from these distortions. We show that the distortions of a particular kind—which we call nonvacuum distortions—can be used to fully reconstruct the initial data. The asymptotic observer can do this operationally by measuring certain well-defined observables of the quantum field at late times. We demonstrate that a general class of in-states encode all their information content in the correlation of late time out-going modes. Further, using a 1 +1 dimensional dilatonic black hole model to accommodate backreaction self-consistently, we show that observers can also infer and track the information content about the initial data, during the course of evaporation, unambiguously. Implications of such information extraction are discussed.
Thermodynamics of Charged AdS Black Holes in Extended Phases Space via M2-branes Background
Chabab, M; Masmar, K
2015-01-01
Motivated by a recent work on asymptotically Ad$S_4$ black holes in M-theory, we investigate both thermodynamics and thermodynamical geometry of Raissner-Nordstrom-AdS black holes from M2-branes. More precisely, we study AdS black holes in $AdS_{4}\\times S^{7}$, with the number of M2-branes interpreted as a thermodynamical variable. In this context, we calculate various thermodynamical quantities including the chemical potential, and examine their phase transitions along with the corresponding stability behaviors. In addition, we also evaluate the thermodynamical curvatures of the Weinhold, Ruppeiner and Quevedo metrics for M2-branes geometry to study the stability of such black object. We show that the singularities of these scalar curvature's metrics reproduce similar stability results obtained by the phase transition program via the heat capacities in different ensembles either when the number of the M2 branes or the charge are held fixed. Also, we note that all results derived in [1] are recovered in the ...
A note on black-hole physics, cosmic censorship, and the charge-mass relation of atomic nuclei
Hod, Shahar
2016-02-01
Arguing from the cosmic censorship principle, one of the fundamental cornerstones of black-hole physics, we have recently suggested the existence of a universal upper bound relating the maximal electric charge of a weakly self-gravitating system to its total mass: Z(A)≤slant {Z}*(A)\\equiv {α }-1/3{A}2/3, where Z is the number of protons in the system, A is the total baryon (mass) number, and α ={e}2/{{\\hslash }}c is the dimensionless fine-structure constant. In order to test the validity of this suggested bound, we here explore the Z(A) functional relation of atomic nuclei as deduced from the Weizsäcker semi-empirical mass formula. It is shown that all atomic nuclei, including the meta-stable maximally charged ones, conform to the suggested charge-mass upper bound. Our results support the validity of the cosmic censorship conjecture in black-hole physics.
Trova, A; Slany, P; Kovar, J
2016-01-01
We present an analytical approach for the equilibrium of a self-gravitating charged fluid embedded in a spherical gravitational and dipolar magnetic fields produced by a central mass. Our scheme is proposed, as a toy-model, in the context of gaseous/dusty tori surrounding supermassive black holes in galactic nuclei. While the central black hole dominates the gravitational field and it remains electrically neutral, the surrounding material has a non-negligible self-gravitational effect on the torus structure. By charging mechanisms it also acquires non-zero electric charge density, so the two influences need to be taken into account to achieve a self-consistent picture. With our approach we discuss the impact of self-gravity, represented by the term dt (ratio of the torus total mass to the mass of the central body), on the conditions for existence of the equilibrium and the morphology and typology of the tori. By comparison with a previous work without self-gravity, we show that the conditions can be different...
Institute of Scientific and Technical Information of China (English)
Pan Wei-Zhen; Yang Xue-Jun; Xie Zhi-Kun
2011-01-01
Using a new tortoise coordinate transformation, this paper investigates the Hawking effect from an arbitrarily accelerating charged black hole by the improved Damour-Ruffini method. After the tortoise coordinate transformation,the Klein-Gordon equation can be written as the standard form at the event horizon. Then extending the outgoing wave from outside to inside of the horizon analytically, the surface gravity and Hawking temperature can be obtained automatically. It is found that the Hawking temperatures of different points on the surface are different. The quantum nonthermal radiation characteristics of a black hole near the event horizon is also discussed by studying the Hamilton Jacobi equation in curved spacetime and the maximum overlap of the positive and negative energy levels near the event horizon is given. There is a dimensional problem in the standard tortoise coordinate and the present results may be more reasonable.
Charged Particle Tunnels from the Slowly Varying Reissner-Nordstr(o)m Black Hole
Institute of Scientific and Technical Information of China (English)
YANG Shu-Zheng; CHEN De-You
2007-01-01
Extending Parikh and Wilczek's work to the non-stationary black hole, we discuss the Hawking radiation of the slowly varying Reissner-Nordstr(o)m black hole by considering the unfixed background spacetime and the self-gravitation interaction. The result shows that the tunnelling rate is related to both the variation of Bekenstein-Hawking entropy and the radiation spectrum deviating from the purely thermal one. This is in agreement with Parikh and Wilczek's result. Then a new method to study Hawking radiation of the non-stationary black holes is presented.
The Bisognano-Wichmann theorem for charged states and the conformal boundary of a black hole
Directory of Open Access Journals (Sweden)
Roberto Longo
2000-07-01
Full Text Available This note concerns the study of the incremental entropy of a quantum black hole, based on Operator Algebra methods. Our results are based on the results presented in the references [6,11,12,13].
Tawfik, Abdel Nasser
2015-01-01
Recently, there has been much attention devoted to resolving the quantum corrections to the Bekenstein-Hawking (black hole) entropy, which relates the entropy to the cross-sectional area of the black hole horizon. Using generalized uncertainty principle (GUP), corrections to the geometric entropy and thermodynamics of black hole will be introduced. The impact of GUP on the entropy near the horizon of three types of black holes; Schwarzschild, Garfinkle-Horowitz-Strominger and Reissner-Nordstr\\"om is determined. It is found that the logarithmic divergence in the entropy-area relation turns to be positive. The entropy $S$, which is assumed to be related to horizon's two-dimensional area, gets an additional terms, for instance $2\\, \\sqrt{\\pi}\\, \\alpha\\, \\sqrt{S}$, where $\\alpha$ is the GUP parameter.
Generalized thermodynamic identity and new Maxwell's law for charged AdS black hole
Zhao, Zixu
2016-01-01
We study the thermodynamic properties of the RN-AdS black hole in full phase space and propose a generalized thermodynamic identity. As an example, we use it to find relations of thermodynamical coefficients between the grand canonical and canonical ensembles. We also show, for the first order phase transition, that the usual Maxwell's equal area law should be extended to a new form for the RN-AdS black hole.
Dilaton and axion bremsstrahlung from collisions of cosmic (super)strings
Melkumova, E Y; Salehi, K
2007-01-01
We calculate dilaton and axion radiation generated in the collision of two straight initially unexcited strings and give a rough cosmological estimate of dilaton and axion densities produced via this mechanism in the early universe.
Dilaton and axion bremsstrahlung from collisions of cosmic (super)strings
Melkumova, E. Yu.; Gal'tsov, D. V.; Salehi, K.
2006-01-01
We calculate dilaton and axion radiation generated in the collision of two straight initially unexcited strings and give a rough cosmological estimate of dilaton and axion densities produced via this mechanism in the early universe.
Discovering techni-dilaton at LHC
Matsuzaki, Shinya
2011-01-01
We present discovery signatures of techni-dilaton (TD) at LHC. The TD was predicted long ago as a pseudo Nambu-Goldstone boson (pNGB) associated with the spontaneous breaking of the approximate scale symmetry in the walking technicolor (WTC) (initially dubbed "scale-invariant technicolor"). Being pNGB, the TD should have a mass M_TD lighter than other techni-hadrons like techni-rho meson; It has recently been estimated to be M_TD ~= 500-600 GeV for the typical WTC model, which is well in the discovery range of the ongoing LHC experiment. Noting that all the TD couplings to the standard model (SM) particles arise only through loop of the techni-fermions with their induced Yukawa couplings to the composite TD, we find that the TD-WW and ZZ couplings get dramatically suppressed compared with those of the SM Higgs which has tree-level couplings proportional to their masses. In contrast, TD couplings to gg, t tbar and gamma gamma are not suppressed and hence are relatively enhanced compared to those of the SM Higg...
Techni-dilaton signatures at LHC
Matsuzaki, Shinya
2011-01-01
We explore discovery signatures of techni-dilaton (TD) at LHC. The TD was predicted long ago as a composite pseudo Nambu-Goldstone boson (pNGB) associated with the spontaneous breaking of the approximate scale symmetry in the walking technicolor (WTC). Being pNGB, whose mass arises from the explicit scale-symmetry breaking due to the dynamical mass generation, the TD should have a mass MTD lighter than other techni-hadrons, say MTD \\simeq 600GeV for the typical WTC model, which is well in the discovery range of the ongoing LHC experiment. We develop a spurion method of nonlinear realization to calculate the TD couplings to the standard model (SM) particles and explicitly evaluate the TD LHC production cross sections at sqrt{s}=7TeV times the branching ratios in terms of MTD as an input parameter for 200GeVWW/ZZ signature with the recent ATLAS and CMS bounds and find that in the case of 1DM the signature is consistent over the whole mass range due to the large suppression of TD couplings, and by the same token...
Castello-Branco, K H C
2013-01-01
We investigate, in the case of a Reissner-Nordstr\\"om black hole, the definitions of gravitational energy and gravitational pressure that naturally arise in the framework of the Teleparallel Equivalent of General Relativity. In particular, we calculate the gravitational energy enclosed by the event horizon of the black hole, E, and the radial pressure over it, p. With these quantities we then analyse the thermodynamic relation dE + pdV (as p turns out to be a density, dV is actually given by dV = dr d\\theta d\\phi, in spherically-type coordinates). We compare the latter with the standard first law of black hole dynamics. Also, by identifying TdS = dE + pdV, we comment on a possible modification of the standard, Bekenstein-Hawking entropy-area relation due to gravitational energy and gravitational pressure of the black hole. The infinitesimal variations in question refer to the Penrose process for a Reissner-Nordstr\\"om black hole.
Geometrical method for thermal instability of nonlinearly charged BTZ Black Holes
Hendi, Seyed Hossein; Panah, Behzad Eslam
2015-01-01
In this paper we consider three dimensional BTZ black holes with three models of nonlinear electrodynamics as source. Calculating heat capacity, we study the stability and phase transitions of these black holes. We show that Maxwell, logarithmic and exponential theories yield only type one phase transition which is related to the root(s) of heat capacity. Whereas for correction form of nonlinear electrodynamics, heat capacity contains two roots and one divergence point. Next, we use geometrical approach for studying classical thermodynamical behavior of the system. We show that Weinhold and Ruppeiner metrics fail to provide fruitful results and the consequences of the Quevedo approach are not completely matched to the heat capacity results. Then, we employ a new metric for solving this problem. We show that this approach is successful and all divergencies of its Ricci scalar and phase transition points coincide. We also show that there is no phase transition for uncharged BTZ black holes.
Anabalón, Andrés; Deruelle, Nathalie; Julié, Félix-Louis
2016-08-01
In this paper we describe 4-dimensional gravity coupled to scalar and Maxwell fields by the Einstein-Katz action, that is, the covariant version of the "Gamma-Gamma -Gamma-Gamma" part of the Hilbert action supplemented by the divergence of a generalized "Katz vector". We consider static solutions of Einstein's equations, parametrized by some integration constants, which describe an ensemble of asymptotically AdS black holes. Instead of the usual Dirichlet boundary conditions, which aim at singling out a specific solution within the ensemble, we impose that the variation of the action vanishes on shell for the broadest possible class of solutions. We will see that, when a long-range scalar "hair" is present, only sub-families of the solutions can obey that criterion. The Katz-Bicak-Lynden-Bell ("KBL") superpotential built on this (generalized) vector will then give straightforwardly the Noether charges associated with the spacetime symmetries (that is, in the static case, the mass). Computing the action on shell, we will see next that the solutions which obey the imposed variational principle, and with Noether charges given by the KBL superpotential, satisfy the Gibbs relation, the Katz vectors playing the role of "counterterms". Finally, we show on the specific example of dyonic black holes that the sub-class selected by our variational principle satisfies the first law of thermodynamics when their mass is defined by the KBL superpotential.