Charged rotating black holes at large D
Tanabe, Kentaro
2016-01-01
We study odd dimensional charged equally rotating black holes in the Einstein-Maxwell theory with/without a cosmological constant by using the large D expansion method, where D is a spacetime dimension. Solving the Einstein-Maxwell equations in the 1/D expansion we obtain the large D effective equations for charged equally rotating black holes. The effective equations describe the nonlinear dynamics of charged equally rotating black holes. Especially the perturbation analysis of the effective equations gives analytic formula for quasinormal mode frequencies, and we can show charged equally rotating black holes have instabilities. As one interesting feature of instabilities, we observe that the ultraspinning instability of neutral equally rotating black holes in de Sitter is connected with the instability of de Sitter Reissner-Nordstrom black hole in a rotation-charge plane of the solution parameter space. So these instabilities have same origin as dynamical properties of charged rotating black holes. We also ...
Charged rotating black holes at large D
Tanabe, Kentaro
2016-01-01
We study odd dimensional charged equally rotating black holes in the Einstein-Maxwell theory with/without a cosmological constant by using the large D expansion method, where D is a spacetime dimension. Solving the Einstein-Maxwell equations in the 1/D expansion we obtain the large D effective equations for charged equally rotating black holes. The effective equations describe the nonlinear dynamics of charged equally rotating black holes. Especially the perturbation analysis of the effective...
Charged rotating noncommutative black holes
International Nuclear Information System (INIS)
In this paper we complete the program of the noncomutative geometry inspired black holes, providing the richest possible solution, endowed with mass, charge and angular momentum. After providing a prescription for employing the Newman-Janis algorithm in the case of nonvanishing stress tensors, we find regular axisymmetric charged black holes in the presence of a minimal length. We study also the new thermodynamics and we determine the corresponding higher-dimensional solutions. As a conclusion we make some consideration about possible applications.
Charged rotating noncommutative black holes
Modesto, Leonardo; Nicolini, Piero
2010-11-01
In this paper we complete the program of the noncomutative geometry inspired black holes, providing the richest possible solution, endowed with mass, charge and angular momentum. After providing a prescription for employing the Newman-Janis algorithm in the case of nonvanishing stress tensors, we find regular axisymmetric charged black holes in the presence of a minimal length. We study also the new thermodynamics and we determine the corresponding higher-dimensional solutions. As a conclusion we make some consideration about possible applications.
Charged rotating noncommutative black holes
Modesto, Leonardo
2010-01-01
In this paper we complete the program of the Noncomutative Geometry inspired black holes, providing the richest possible solution, endowed with mass, charge and angular momentum. After providing a prescription for employing the Newmann-Janis algorithm in case of nonvanishing stress tensors, we find regular axisymmetric charged black holes in the presence of a minimal length. We study also the new thermodynamics and we determine the corresponding higher-dimensional solutions. As a conclusion we make some consideration about possible applications.
Higher-dimensional Rotating Charged Black Holes
Caldarelli, Marco M; Van Pol, Bert
2010-01-01
Using the blackfold approach, we study new classes of higher-dimensional rotating black holes with electric charges and string dipoles, in theories of gravity coupled to a 2-form or 3-form field strength and to a dilaton with arbitrary coupling. The method allows to describe not only black holes with large spin, but also other regimes that include charged black holes near extremality with slow rotation. We construct explicit examples of electric rotating black holes of dilatonic and non-dilatonic Einstein-Maxwell theory, with horizons of spherical and non-spherical topology. We also find new families of solutions with string dipoles, including a new class of prolate black rings. Whenever there are exact solutions that we can compare to, their properties in the appropriate regime are reproduced precisely by our solutions. The analysis of blackfolds with string charges requires the formulation of the dynamics of anisotropic fluids with conserved string-number currents, which is new, and is carried out in detail...
Charged Rotating Black Branes in Various Dimensions
Khodam-Mohammadi, A
2007-01-01
In this thesis, two different aspects of asymptotically charged rotating black branes in various dimensions are studied. In the first part, the thermodynamics of these spacetimes is investigated, while in the second part the no hair theorem for these spacetimes in four dimensions is considered. In part I, first, the Euclidean actions of a d-dimensional charged rotating black brane are computed through the use of the counterterms renormalization method both in the canonical and the grand-canonical ensemble, and it is shown that the logarithmic divergencies associated to the Weyl anomalies and matter field vanish. Second, a Smarr-type formula for the mass as a function of the entropy, the angular momenta and the electric charge is obtained, which shows that these quantities satisfy the first law of thermodynamics. Third, by using the conserved quantities and the Euclidean actions, the thermodynamics potentials of the system in terms of the temperature, the angular velocities and the electric potential are obtai...
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.
Entropy bound of horizons for charged and rotating black holes
International Nuclear Information System (INIS)
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
Charged Rotating Kaluza-Klein Black Holes in Five Dimensions
Nakagawa, Toshiharu; Matsuno, Ken; Tomizawa, Shinya
2008-01-01
We construct a new charged rotating Kaluza-Klein black hole solution in the five-dimensional Einstein-Maxwell theory with a Chern-Simon term. The features of the solutions are also investigated. The spacetime is asymptotically locally flat, i.e., it asymptotes to a twisted $\\rm S^1$ bundle over the four-dimensional Minkowski spacetime. The solution describe a non-BPS black hole rotating in the direction of the extra dimension. The solutions have the limits to the supersymmetric black hole solutions, a new extreme non-BPS black hole solutions and a new rotating non-BPS black hole solution with a constant twisted $\\rm S^1$ fiber.
Hawking temperature of rotating charged black strings from tunneling
Energy Technology Data Exchange (ETDEWEB)
Ahmed, Jamil; Saifullah, K., E-mail: jamil_051@yahoo.com, E-mail: saifullah@qau.edu.pk [Department of Mathematics, Quaid-i-Azam University, Islamabad (Pakistan)
2011-11-01
Thermal radiations from spherically symmetric black holes have been studied from the point of view of quantum tunneling. In this paper we extend this approach to study radiation of fermions from charged and rotating black strings. Using WKB approximation and Hamilton-Jacobi method we work out the tunneling probabilities of incoming and outgoing fermions and find the correct Hawking temperature for these objects. We show that in appropriate limits the results reduce to those for the uncharged and non-rotating black strings.
Hawking temperature of rotating charged black strings from tunneling
Ahmed, Jamil
2011-01-01
Thermal radiations from spherically symmetric black holes have been studied from the point of view of quantum tunneling. In this paper we extend this approach to study radiation of fermions from charged and rotating black strings. Using WKB approximation and Hamilton-Jacobi method we work out the tunneling probabilities of incoming and outgoing fermions and find the correct Hawking temperature for these objects. We show that in appropriate limits the results reduce to those for the uncharged and non-rotating black strings.
Tunneling of Massive Vector Particles From Rotating Charged Black Strings
Jusufi, Kimet; Övgün, Ali
2016-01-01
We study the quantum tunneling of charged massive vector bosons from a charged static and a rotating black string. We apply the standard methods, first we use the WKB approximation and the Hamilton-Jacobi equation, and then we end up with a set of four linear equations. Finally, solving for the radial part by using the determinant of the metric equals zero, the corresponding tunneling rate and the Hawking temperature is recovered in both cases. The tunneling rate deviates from pure thermality...
Corrected Entropy Law for Charged and Rotating Black Strings
Rizwan, Muhammad
2016-08-01
The primary objective in this work is to study the corrected entropy law for charged and rotating black strings in asymptotically anti-de Sitter spacetime. By employing, the Hamilton-Jacobi approach, fermions tunneling beyond semiclassical approximation is investigated. The correction has been done by taking the proportionality parameters of quantum correction of action I i to the semiclassical action I 0 as 2 π times the inverse of the black string horizon area. Moreover, with the aid of corrected Hawking temperature we finally compute the corrected area law, which includes the logarithmic term and inverse area terms.
Tunneling of Massive Vector Particles From Rotating Charged Black Strings
Jusufi, Kimet
2015-01-01
We study the quantum tunneling of charged massive vector bosons from a charged static and a rotating black string. We apply the standard methods, first we use the WKB approximation and the Hamilton-Jacobi equation, and then we end up with a set of four linear equations. Finally, solving for the radial part by using the determinant of the metric equals zero, the corresponding tunneling rate and the Hawking temperature is recovered in both cases. The tunneling rate deviates from pure thermality and is consistent with an underlying unitary theory.
Tunneling of massive vector particles from rotating charged black strings
Jusufi, Kimet; Övgün, Ali
2016-07-01
We study the quantum tunneling of charged massive vector bosons from a charged static and a rotating black string. We apply the standard methods, first we use the WKB approximation and the Hamilton-Jacobi equation, and then we end up with a set of four linear equations. Finally, solving for the radial part by using the determinant of the metric equals zero, the corresponding tunneling rate and the Hawking temperature is recovered in both cases. The tunneling rate deviates from pure thermality and is consistent with an underlying unitary theory.
Slowly rotating regular black holes with a charged thin shell
Uchikata, Nami
2015-01-01
We obtain rotating solutions of regular black holes which are constructed of de Sitter spacetime with the axisymmetric stationary perturbation within the timelike charged thin shell and the Kerr-Newman geometry with sufficiently small rotation outside the shell. To treat the slowly rotating thin shell, we employ the method developed by de la Cruz and Israel. The thin shell is assumed to be composed of a dust in the zero-rotation limit and located inside the inner horizon of the black hole solution. We expand the perturbation in powers of the rotation parameter of the Kerr-Newman metric up to the second order. It is found that with the present treatment, the stress tensor of the thin shell in general has anisotropic pressure, i.e., the thin shell cannot be composed of a dust if the rotational effects are taken into account. However, the thin shell can be composed of a perfect fluid with isotropic pressure if the degrees of freedom appearing in the physically acceptable matching of the two distinct spacetimes a...
Charged Massive Particle's Tunneling From Charged Non-Rotating Micro Black Hole
Soleimani, M J; Radiman, Shahidan; Abdullah, W A T Wan
2015-01-01
In the tunneling framework of Hawking radiation, charged massive particle's tunneling in charged non-rotating TeV-Scale black hole is investigated. To this end, we consider natural cutoffs as a minimal length, a minimal momentum, and a maximal momentum through a generalized uncertainty principle. We focus on the role played by these natural cutoffs on the luminosity of charged non-rotating micro black hole by taking into account the full implications of energy and charge conservation as well as the back- scattered radiation.
Charged rotating Kaluza-Klein black holes generated by G2(2) transformation
International Nuclear Information System (INIS)
Applying the G2(2) generating technique for minimal D = 5 supergravity to the Rasheed black hole solution, we present a new rotating charged Kaluza-Klein black hole solution to the five-dimensional Einstein-Maxwell-Chern-Simons equations. At infinity, our solution behaves as a four-dimensional flat spacetime with a compact extra dimension and hence describes a Kaluza-Klein black hole. In particular, the extreme solution is non-supersymmetric, which is in contrast to a static case. Our solution has the limits to the asymptotically flat charged rotating black hole solution and a new charged rotating black string solution.
Charged Rotating Kaluza-Klein Black Holes Generated by G2(2) Transformation
Tomizawa, Shinya; Morisawa, Yoshiyuki
2008-01-01
Applying the G_{2(2)} generating technique for minimal D=5 supergravity to the Rasheed black hole solution, we present a new rotating charged Kaluza-Klein black hole solution to the five-dimensional Einstein-Maxwell-Chern-Simons equations. At infinity, our solution behaves as a four-dimensional flat spacetime with a compact extra dimension and hence describes a Kaluza-Klein black hole. In particlar, the extreme solution is non-supersymmetric, which is contrast to a static case. Our solution has the limits to the asymptotically flat charged rotating black hole solution and a new charged rotating black string solution.
A new metric for rotating charged Gauss—Bonnet black holes in AdS space
International Nuclear Information System (INIS)
In this paper, we study a new metric for slowly rotating charged Gauss-Bonnet black holes in higher-dimensional anti-de Sitter space. Taking the angular momentum parameter a up to second order, the slowly rotating charged black hole solutions are obtained by working directly in the action. (general)
Charged Black Holes in a Rotating Gross-Perry-Sorkin Monopole Background
Tomizawa, Shinya
2008-01-01
We present a new class of stationary charged black hole solutions to five-dimensional Einstein-Maxwell-Chern-Simons theories. We construct the solutions by utilizing so called the squashing transformation. At infinity, our solutions behave as a four-dimensional flat spacetime plus a `circle' and hence describe a Kaluza-Klein black hole. More precisely, our solutions can be viewed as a charged rotating black hole in a rotating Gross-Perry-Sorkin monopole background with the black hole rotation induced from the background rotation.
Hawking radiation of scalars from charged accelerating and rotating black holes with NUT parameter
Jan, Khush
2013-01-01
We study the quantum tunneling of scalars from charged accelerating and rotating black hole with NUT parameter. For this purpose we use the charged Klein-Gordon equation. We apply WKB approximation and the Hamilton-Jacobi method to solve charged the Klein-Gordon equation. We find the tunneling probability of outgoing charged scalars from the event horizon of this black hole, and hence the Hawking temperature for this black hole.
Sheykhi, A.; Dehghani, M. H.; 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 ar...
Wu, Shuang-Qing
2008-03-28
I present the general exact solutions for nonextremal rotating charged black holes in the Gödel universe of five-dimensional minimal supergravity theory. They are uniquely characterized by four nontrivial parameters: namely, the mass m, the charge q, the Kerr equal rotation parameter a, and the Gödel parameter j. I calculate the conserved energy, angular momenta, and charge for the solutions and show that they completely satisfy the first law of black hole thermodynamics. I also study the symmetry and separability of the Hamilton-Jacobi and the massive Klein-Gordon equations in these Einstein-Maxwell-Chern-Simons-Gödel black hole backgrounds. PMID:18517852
Wu, Shuang-Qing
2008-03-01
I present the general exact solutions for nonextremal rotating charged black holes in the Gödel universe of five-dimensional minimal supergravity theory. They are uniquely characterized by four nontrivial parameters: namely, the mass m, the charge q, the Kerr equal rotation parameter a, and the Gödel parameter j. I calculate the conserved energy, angular momenta, and charge for the solutions and show that they completely satisfy the first law of black hole thermodynamics. I also study the symmetry and separability of the Hamilton-Jacobi and the massive Klein-Gordon equations in these Einstein-Maxwell-Chern-Simons-Gödel black hole backgrounds.
Fermions tunneling from charged accelerating and rotating black holes with NUT parameter
Energy Technology Data Exchange (ETDEWEB)
Sharif, M.; Javed, Wajiha [University of the Punjab, Quaid-e-Azam Campus, Department of Mathematics, Lahore (Pakistan)
2012-05-15
This paper is devoted to the study of Hawking radiation as a tunneling of charged fermions through event horizons of a pair of charged accelerating and rotating black holes with NUT parameter. We evaluate tunneling probabilities of outgoing charged particles by using the semiclassical WKB approximation to the general covariant Dirac equation. The Hawking temperature corresponding to this pair of black holes is also investigated. For the zero NUT parameter, we find results consistent with those already available in the literature. (orig.)
Wu, Shuang-Qing
2007-01-01
We present the general exact solutions for non-extremal rotating charged black holes in the Godel universe of five-dimensional minimal supergravity theory. They are uniquely characterized by four non-trivial parameters, namely the mass $m$, the charge $q$, the Kerr rotation parameter $a$, and the Godel parameter $j$. The metrics in general describe regular rotating charged black holes embedded in the Godel universe, providing the parameters lie in appropriate ranges so that naked singularities and closed timelike curves are avoided. We calculate the conserved energy, angular momenta and charge for the solutions and show that they completely satisfy the first law of black hole thermodynamics. We also study the separability of the Hamilton-Jacobi and the massive Klein-Gordon equations in these Einstein-Maxwell-Chern-Simons-Godel black hole backgrounds.
Sakalli, I.
2016-01-01
Hawking radiation of charged massive spin-0 particles 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 analyze the behavior of the wave solutions near the event horizon of the rotating linear dilaton black h...
A uniqueness theorem for charged rotating black holes in five-dimensional minimal supergravity
Tomizawa, Shinya; Ishibashi, Akihiro
2009-01-01
We show a uniqueness theorem for charged rotating black holes in the bosonic sector of five-dimensional minimal supergravity. More precisely, under the assumptions of the existence of two commuting axial isometries and spherical topology of horizon cross-sections, we prove that an asymptotically flat, stationary charged rotating black hole with finite temperature in five-dimensional Einstein-Maxwell-Chern-Simons theory is uniquely characterized by the mass, charge, and two independent angular momenta and therefore is described by the Chong-Cvetic-Lu-Pope solution.
International Nuclear Information System (INIS)
By using a new approach, we demonstrate the analytic expressions for slowly rotating Gauss—Bonnet charged black hole solutions with one non-vanishing angular momentum in higher-dimensional anti-de Sitter spaces. Up to linear order of the rotating parameter a, the mass, Hawking temperature and entropy of the charged black holes get no corrections from rotation. (general)
International Nuclear Information System (INIS)
By using a new approach, we demonstrate the analytic expressions for slowly rotating Gauss-Bonnet charged black hole solutions with one non-vanishing angular momentum in higher-dimensional anti-de Sitter spaces. Up to linear order of the rotating parameter a, the mass, Hawking temperature and entropy of the charged black holes get no corrections from rotation. (authors)
Thermal Stability Of Charged Rotating Quantum Black Holes In Diverse Dimensions
Sinha, Aloke Kumar
2015-01-01
Criteria for thermal stability of charged rotating black holes of any dimension are derived, for horizon areas that are large relative to the Planck area (in these dimensions). The derivation uses results of loop quantum gravity and equilibrium statistical mechanics of the Grand Canonical ensemble. There is no explicit use of classical spacetime geometry at all in this analysis. The only assumption is that the mass of the black hole is a function of its horizon area, charge and angular momentum. Our stability criteria are then tested in detail against specific classical black holes in spacetime dimensions 4 and 5, whose metrics provide us with explicit relations for the dependence of the mass on the charge and angular momentum of the black holes. This enables us to predict which of these black holes are expected to be thermally unstable under Hawking radiation.
Quantum Tunneling from the Charged Non-Rotating BTZ Black Hole with GUP
Sadeghi, Jafar; Shajiee, Vahid Reza
2016-01-01
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 generalized uncertainty principle in 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. It is shown that the black hole, in presence of GUP, would be more thermodynamically stable than classical case. Finally, ...
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.
Sakalli, I
2016-01-01
Hawking radiation of charged massive spin-0 particles 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 analyze the behavior of the wave solutions near the event horizon of the rotating linear dilaton black hole and derive its Hawking radiation spectrum via the Damour--Ruffini--Sannan method.
Quantum Tunneling from the Charged Non-Rotating BTZ Black Hole with GUP
Sadeghi, Jafar
2016-01-01
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 generalized uncertainty principle in 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. It is shown that the black hole, in presence of GUP, would be more thermodynamically stable than classical case. Finally, some discussion are presented about the black hole heat capacity.
Electrically charged matter in rigid rotation around magnetized black hole
Czech Academy of Sciences Publication Activity Database
Kovář, J.; Slaný, P.; Cremaschini, C.; Stuchlík, Z.; Karas, Vladimír; Trova, Audrey
2014-01-01
Roč. 90, č. 4 (2014), 044029/1-044029/14. ISSN 1550-7998 R&D Projects: GA ČR GB14-37086G Grant ostatní: GA ČR(CZ) GP14-07753P Institutional support: RVO:67985815 Keywords : black hole s * accretion disks Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics Impact factor: 4.643, year: 2014
Entropy of a rotating and charged black string to all orders in the Planck length
International Nuclear Information System (INIS)
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
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.
Stability of rapidly-rotating charged black holes in $AdS_5 \\times S^5$
Berkooz, Micha; Zait, Amir
2013-01-01
We study the stability of charged rotating black holes in a consistent truncation of Type $IIB$ Supergravity on $AdS_5 \\times S^5$ that degenerate to extremal black holes with zero entropy. These black holes have scaling properties between charge and angular momentum similar to those of Fermi surface-like operators in a subsector of ${\\cal N}=4$ SYM. By solving the equation of motion for a massless scalar field in this background, using matched asymptotic expansion followed by a numerical solution scheme, we are able to compute its Quasi-Normal modes, and analyze it's regime of (in)stability. We find that the black hole is unstable when its angular velocity with respect to the horizon exceeds 1 (in units of $1/l_{AdS}$). A study of the relevant thermodynamic Hessian reveals a local thermodynamic instability which occurs at the same region of parameter space. We comment on the endpoints of this instability.
Institute of Scientific and Technical Information of China (English)
ZOU De-Cheng; YANG Zhan-Ying; YUE Rui-Hong
2011-01-01
@@ By using a new approach, we demonstrate the analytic expressions for slowly rotating Gauss-Bonnet charged black hole solutions with one non-vanishing angular momentum in higher-dimensional anti-de Sitter spaces.Up to linear order of the rotating parameter a, the mass, Hawking temperature and entropy of the charged black holes get no corrections from rotation.%By using a new approach, we demonstrate the analytic expressions for slowly rotating Gauss-Bonnet charged black hole solutions with one non-vanishing angular momentum in higher-dimensionalanti-de Sitter spaces. Up to linear order of the rotating parameter a, the mass, Hawking temperature and entropy of the charged black holes get no corrections from rotation.
Shadow of a Charged Rotating Black Hole in $f(R)$ Gravity
Dastan, Sara; Soroushfar, Saheb
2016-01-01
We study the shadow of a charged rotating black hole in $f(R)$ gravity. This black hole is characterized by mass, $M$, spin, $a$, electric charge, $Q$ and $R_{0}$ which is proportional to cosmological constant. We analyze the image of the black hole's shadow in four types 1) at $r\\rightarrow\\infty$, 2) at $r\\rightarrow r_{o}$, in vacuum, 3) at $r\\rightarrow\\infty$, 4) at $r\\rightarrow r_{o}$, for an observer at the presence of plasma. Moreover, we investigate the effect of spin, charge and modfication of gravity on the shape of shadow. In addition, we use two observables, the radius $R_{s}$ and the distortion parameter $\\delta_{s}$, characterizing the apparent shape. We show that for all cases, the shadow becomes smaller with increasing electric charge. Also, by increasing the rotation parameters, circular symmetry of the image of black hole's shadow will change. Furthermore, in the presence of plasma, plasma parameter also effects on size of the shadow.
Statistical mechanical origin of the entropy of a rotating, charged black hole
International Nuclear Information System (INIS)
It is shown that the entropy of a rotating, charged black hole is, in senses made precise in the paper, (i) the logarithm of the number of quantum mechanically distinct ways that the hole could have been made, and (ii) the logarithm of the number of configurations that the hole's ''atmosphere,'' as measured by stationary observers, could assume in the presence of its background noise of acceleration radiation. In addition, a proof is given of the generalized second law of thermodynamics
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.)
Superradiance and instability of small rotating charged AdS black holes in all dimensions
International Nuclear Information System (INIS)
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.)
Tunnelling of scalar and Dirac particles from squashed charged rotating Kaluza-Klein black holes
Stetsko, M M
2014-01-01
Thermal radiation of scalar particles and Dirac fermions from squashed charged rotating five-dimensional black holes is considered. To obtain temperature of the black holes we use the tunnelling method. In 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 radial parts of the action for scalar particles and fermions in quasi-classical limit in the vicinity of horizon are almost the same and as a consequence it gives rise to the identical expressions for the temperature in both cases.
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.
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.)
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
International Nuclear Information System (INIS)
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...
Thermodynamics of charged rotating dilaton black branes with power-law Maxwell field
Zangeneh, M. Kord; Sheykhi, A.; Dehghani, M. H.
2015-10-01
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.
Magnetic field seed generation in plasmas around charged and rotating black holes
International Nuclear Information System (INIS)
Previous work by the authors introduced the possibility of generating seed magnetic fields by spacetime curvature and applied it in the vicinity of a Schwarzschild black hole. It was pointed out that it would be worthwhile to consider the effect in other background geometries and particularly in the vicinity of a rotating black hole, which is generically to be expected, astrophysically. In this paper that suggestion is followed up and we calculate generated magnetic field seed due to Reissner–Nördstrom and Kerr spacetimes. The conditions for the drive for the seed of a magnetic field is obtained for charged black holes, finding that in the horizon the drive vanishes. Also, the ψN-force produced by the Kerr black hole is obtained and its relation with the magnetic field seed is discussed, producing a more effective drive. (paper)
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.
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...
Tursunov, Arman; Stuchlík, Zdeněk; Kološ, Martin
2016-04-01
We study the motion of charged particles in the field of a rotating black hole immersed into an external asymptotically uniform magnetic field, focusing on the epicyclic quasicircular 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 analyze 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 an 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 particles in the radial and vertical directions related to the equatorial circular orbits and study the radial profiles of the radial, ωr; vertical, ωθ; and orbital, ωϕ, frequencies, finding significant differences in comparison to the epicyclic geodesic circular motion. The most important new phenomenon is the existence of toroidal charged particle epicyclic motion with ωr˜ωθ≫ωϕ that could occur around retrograde circular orbits with an outward-oriented Lorentz force. We demonstrate that for the rapidly rotating black holes the role of the "Wald induced charge" can be relevant.
Integrability of some charged rotating supergravity black hole solutions in four and five dimensions
Vasudevan, Muraari
2005-09-01
We study the integrability of geodesic flow in the background of some recently discovered charged rotating solutions of supergravity in four and five dimensions. Specifically, we work with the gauged multicharge Taub-NUT-Kerr-(anti-)de Sitter metric in four dimensions, and the U(1) 3 gauged charged-Kerr-(anti-)de Sitter black hole solution of N = 2 supergravity in five dimensions. We explicitly construct the nontrivial irreducible Killing tensors that permit separation of the Hamilton-Jacobi equation in these spacetimes. These results prove integrability for a large class of previously known supergravity solutions, including several BPS solitonic states. We also derive first-order equations of motion for particles in these backgrounds and examine some of their properties. Finally, we also examine the Klein-Gordon equation for a scalar field in these spacetimes and demonstrate separability.
Near-BPS-saturated rotating electrically charged black holes as string states
International Nuclear Information System (INIS)
We construct generating solutions for general D-dimensional (4≤D≤9) rotating, electrically charged, black holes in the effective action of toroidally compactified heterotic (or Type IIA) string. The generating solution is parameterized by the ADM mass, two electric charges and [(D-1)/2] angular momenta (as well as the asymptotic values of one toroidal modulus and the dilaton field). For D≥6, those are generating solutions for general black holes in toroidally compactified heterotic (or type IIA) string. Since in the BPS-limit (extreme limit) these solutions have singular horizons or naked singularities, we address the near extreme solutions with all the angular momenta small enough. In this limit, the thermodynamic entropy can be cast in a suggestive form, which has a qualitative interpretation as microscopic entropy of (near)-BPS-saturated charged string states of toroidally compactified heterotic string, whose target-space angular momenta are identified as [(D-1)/2] U(1) left-moving world-sheet currents. (orig.)
Butterflies with rotation and charge
Reynolds, Alan P
2016-01-01
We explore the butterfly effect for black holes with rotation or charge. We perturb rotating BTZ and charged black holes in 2+1 dimensions by adding a small perturbation on one asymptotic region, described by a shock wave in the spacetime, and explore the effect of this shock wave on the length of geodesics through the wormhole and hence on correlation functions. We find the effect of the perturbation grows exponentially at a rate controlled by the temperature; dependence on the angular momentum or charge does not appear explicitly. We comment on issues affecting the extension to higher-dimensional charged black holes.
Fermions tunneling from rotating stationary Kerr black hole with electric charge and magnetic charge
Yang, Juan; Yang, Shu-Zheng
2010-06-01
In this paper, the method of semi-classical fermion tunneling is extended to explore the fermion tunneling behavior of a Kerr-Newman-Kasuya black hole. Thus, the Hamilton-Jacobi equation in Kerr-Newman-Kasuya space-time is derived by the method presented in Refs. Lin and Yang (2009) [24-26], the Hawking temperature at the horizon and the tunneling probability of spin- 1/2 fermions are finally obtained following the semi-classical quantum equation. The results indicate the common features of this black hole.
Charged, Rotating Black Objects in Einstein–Maxwell-Dilaton Theory in D ≥ 5
Burkhard Kleihaus; Jutta Kunz; Eugen Radu
2016-01-01
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 blac...
Charged, rotating black objects in Einstein-Maxwell-dilaton theory in $D\\ge 5$
Kleihaus, Burkhard; Kunz, Jutta; 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. B...
Charge and mass effects on the evaporation of higher-dimensional rotating black holes
International Nuclear Information System (INIS)
To study the dynamics of discharge of a brane black hole in TeV gravity scenarios, we obtain the approximate electromagnetic field due to the charged black hole, by solving Maxwell's equations perturbatively on the brane. In addition, arguments are given for brane metric corrections due to backreaction. We couple brane scalar and brane fermion fields with non-zero mass and charge to the background, and study the Hawking radiation process using well known low energy approximations as well as a WKB approximation in the high energy limit. We argue that contrary to common claims, the initial evaporation is not dominated by fast Schwinger discharge.
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.
Mo, Jie-Xiong
2014-01-01
To provide an analytic verification of the nature of phase transition at the critical point of $P-V$ criticality, the original expressions of Ehrenfest equations have been introduced directly. By treating the cosmological constant and its conjugate quantity as thermodynamic pressure and volume respectively, we carry out analytical check of classical Ehrenfest equations. To show that our approach is universal, we investigate not only higher-dimensional charged AdS black holes, but also rotating AdS black holes. Not only are the examples of Einstein gravity shown, but also the example of modified gravity is presented for Gauss-Bonnet AdS black holes. The specific heat at constant pressure $C_P$, the volume expansion coefficient $\\alpha$ and the isothermal compressibility coefficient $\\kappa_T$ are found to diverge exactly at the critical point. It has been verified that both Ehrenfest equations hold at the critical point of $P-V$ criticality in the extended phase spaces of AdS black holes. So the nature of the ...
Charged and rotating AdS black holes and their CFT duals
Hawking, S. W.; Reall, H. S.
2000-01-01
Black hole solutions that are asymptotic to AdS5×S5 or AdS4×S7 can rotate in two different ways. If the internal sphere rotates, then one can obtain a Reissner-Nordström-AdS black hole. If the asymptotically AdS space rotates, then one can obtain a Kerr-AdS hole. One might expect superradiant scattering to be possible in either of these cases. Superradiant modes reflected off the potential barrier outside the hole would be reamplified at the horizon, and a classical instability would result. We point out that the existence of a Killing vector field timelike everywhere outside the horizon prevents this from occurring for black holes with negative action. Such black holes are also thermodynamically stable in the grand canonical ensemble. The CFT duals of these black holes correspond to a theory in an Einstein universe with a chemical potential and a theory in a rotating Einstein universe. We study these CFTs in the zero coupling limit. In the first case, Bose-Einstein condensation occurs on the boundary at a critical value of the chemical potential. However, the supergravity calculation demonstrates that this is not to be expected at strong coupling. In the second case, we investigate the limit in which the angular velocity of the Einstein universe approaches the speed of light at finite temperature. This is a new limit in which to compare the CFT at strong and weak coupling. We find that the free CFT partition function and supergravity action have the same type of divergence but the usual factor of 4/3 is modified at finite temperature.
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 and rotating AdS black holes and their CFT duals
Hawking, Stephen William
2000-01-01
Black hole solutions that are asymptotic to $ AdS_5 \\times S^5$ or $ AdS_4 then one can obtain a Reissner-Nordstrom-AdS black hole. If the asymptotically AdS space rotates then one can obtain a Kerr-AdS hole. One might expect superradiant scattering to be possible in either of these cases. Superradiant modes reflected off the potential barrier outside the hole would be re-amplified at the horizon, and a classical instability would result. We point out that the existence of a Killing vector field timelike everywhere outside the horizon prevents this from occurring for black holes with negative action. Such black holes are also thermodynamically stable in the grand canonical ensemble. The CFT duals of these black holes correspond to a theory in an Einstein universe with a chemical potential and a theory in a rotating Einstein universe. We study these CFTs in the zero coupling limit. In the first case, Bose-Einstein condensation occurs on the boundary at a critical value of the chemical potential. However the su...
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...
Butterflies with rotation and charge
Reynolds, Alan P.; Ross, Simon F.
2016-01-01
We explore the butterfly effect for black holes with rotation or charge. We perturb rotating BTZ and charged black holes in 2+1 dimensions by adding a small perturbation on one asymptotic region, described by a shock wave in the spacetime, and explore the effect of this shock wave on the length of geodesics through the wormhole and hence on correlation functions. We find the effect of the perturbation grows exponentially at a rate controlled by the temperature; dependence on the angular momen...
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.
Shadow of rotating regular black holes
Abdujabbarov, Ahmadjon; Amir, Muhammed; Ahmedov, Bobomurat; Ghosh, Sushant G.
2016-01-01
We study the shadows cast by the different types of rotating regular black holes viz. Ay\\'on-Beato-Garc\\'ia {(ABG)}, Hayward, and Bardeen. These black holes have in addition to the total mass ($M$) and rotation parameter ($a$), different parameters as electric charge ($Q$), deviation parameter ($g$), and magnetic charge ($g_{*}$), respectively. Interestingly, the size of the shadow is affected by these parameters in addition to the rotation parameter. We found that the radius of the shadow in...
Rotating Brane World Black Holes
Modgil, Moninder Singh; Panda, Sukanta; Sengupta, Gautam
2001-01-01
A five dimensional rotating black string in a Randall-Sundrum brane world is considered. The black string intercepts the three brane in a four dimensional rotating black hole. The geodesic equations and the asymptotics in this background are discussed.
Fischetti, Sebastian
2013-01-01
We construct the gravitational dual, in the Unruh state, of the "jammed" phase of a CFT at strong coupling and infinite N on a fixed five-dimensional rotating Myers-Perry black hole with equal angular momenta. When the angular momenta are all zero, the solution corresponds to the five-dimensional generalization of the solution first studied by Figueras, Lucietti, and Wiseman. In the extremal limit, when the angular momenta of the Myers-Perry black hole are maximum, the Unruh, Boulware and Hartle-Hawking states degenerate. We give a detailed analysis of the corresponding holographic stress energy tensor for all values of the angular momenta, finding it to be regular at the horizon in all cases. We compare our results with existent literature on thermal states of free field theories on black hole backgrounds.
Slowly Rotating Black Holes with Nonlinear Electrodynamics
International Nuclear Information System (INIS)
We study charged slowly rotating black hole with a nonlinear electrodynamics (NED) in the presence of cosmological constant. Starting from the static solutions of Einstein-NED gravity as seed solutions, we use the angular momentum as the perturbative parameter to obtain slowly rotating black holes. We perform the perturbations up to the linear order for black holes in 4 dimensions. These solutions are asymptotically AdS and their horizon has spherical topology. We calculate the physical properties of these black holes and study their dependence on the rotation parameter a as well as the nonlinearity parameter β. In the limit β→∞, the solution describes slowly rotating AdS type black holes
Shadow of rotating regular black holes
Abdujabbarov, Ahmadjon; Ahmedov, Bobomurat; Ghosh, Sushant G
2016-01-01
We study the shadows cast by the different types of rotating regular black holes viz. Ay\\'on-Beato-Garc\\'ia {(ABG)}, Hayward, and Bardeen. These black holes have in addition to the total mass ($M$) and rotation parameter ($a$), different parameters as electric charge ($Q$), deviation parameter ($g$), and magnetic charge ($g_{*}$), respectively. Interestingly, the size of the shadow is affected by these parameters in addition to the rotation parameter. We found that the radius of the shadow in each case decreases monotonically and the distortion parameter increases when the value of these parameters increase. A comparison with the standard Kerr case is also investigated. We have also studied the influence of the plasma environment around regular black holes to discuss its shadow. The presence of the plasma affects the apparent size of the regular black hole's shadow to be increased due to two effects (i) gravitational redshift of the photons and (ii) radial dependence of plasma density.
Shadow of rotating regular black holes
Abdujabbarov, Ahmadjon; Amir, Muhammed; Ahmedov, Bobomurat; Ghosh, Sushant G.
2016-05-01
We study the shadows cast by the different types of rotating regular black holes viz. Ayón-Beato-García (ABG), Hayward, and Bardeen. These black holes have in addition to the total mass (M ) and rotation parameter (a ), different parameters as electric charge (Q ), deviation parameter (g ), and magnetic charge (g*). Interestingly, the size of the shadow is affected by these parameters in addition to the rotation parameter. We found that the radius of the shadow in each case decreases monotonically, and the distortion parameter increases when the values of these parameters increase. A comparison with the standard Kerr case is also investigated. We have also studied the influence of the plasma environment around regular black holes to discuss its shadow. The presence of the plasma affects the apparent size of the regular black hole's shadow to be increased due to two effects: (i) gravitational redshift of the photons and (ii) radial dependence of plasma density.
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.
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...
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...
Area spectrum of slowly rotating black holes
Myung, Yun Soo
2010-01-01
We investigate the area spectrum for rotating black holes which are Kerr and BTZ black holes. For slowly rotating black holes, we use the Maggiore's idea combined with Kunstatter's method to derive their area spectra, which are equally spaced.
Rotating black hole and quintessence
Energy Technology Data Exchange (ETDEWEB)
Ghosh, Sushant G. [Jamia Millia Islamia, Centre for Theoretical Physics, New Delhi (India); University of KwaZulu-Natal, Astrophysics and Cosmology Research Unit, School of Mathematics, Statistics and Computer Science, Private Bag 54001, Durban (South Africa)
2016-04-15
We discuss spherically symmetric exact solutions of the Einstein equations for quintessential matter surrounding a black hole, which has an additional parameter (ω) due to the quintessential matter, apart from the mass (M). In turn, we employ the Newman-Janis complex transformation to this spherical quintessence black hole solution and present a rotating counterpart that is identified, for α = -e{sup 2} ≠ 0 and ω = 1/3, exactly as the Kerr-Newman black hole, and as the Kerr black hole when α = 0. Interestingly, for a given value of parameter ω, there exists a critical rotation parameter (a = a{sub E}), which corresponds to an extremal black hole with degenerate horizons, while for a < a{sub E}, it describes a nonextremal black hole with Cauchy and event horizons, and no black hole for a > a{sub E}. We find that the extremal value a{sub E} is also influenced by the parameter ω and so is the ergoregion. (orig.)
A nonsingular rotating black hole
International Nuclear Information System (INIS)
The spacetime singularities in classical general relativity are inevitable, as predicated by the celebrated singularity theorems. However, it is a general belief that singularities do not exist in Nature and that they are the limitations of the general relativity. In the absence of a welldefined quantum gravity, models of regular black holes have been studied. We employ a probability distribution inspired mass function m(r) to replace the Kerr black hole mass M to represent a nonsingular rotating black hole that is identified asymptotically (r >> k, k > 0 constant) exactly as the Kerr-Newman black hole, and as the Kerr black hole when k = 0. The radiating counterpart renders a nonsingular generalization of Carmeli's spacetime as well as Vaidya's spacetime, in the appropriate limits. The exponential correction factor changing the geometry of the classical black hole to remove the curvature singularity can also be motivated by quantum arguments. The regular rotating spacetime can also be understood as a black hole of general relativity coupled to nonlinear electrodynamics. (orig.)
A nonsingular rotating black hole
Energy Technology Data Exchange (ETDEWEB)
Ghosh, Sushant G. [Jamia Millia Islamia, Centre for Theoretical Physics, New Delhi (India); University of KwaZulu-Natal, Astrophysics and Cosmology Research Unit, School of Mathematical Sciences, Durban (South Africa)
2015-11-15
The spacetime singularities in classical general relativity are inevitable, as predicated by the celebrated singularity theorems. However, it is a general belief that singularities do not exist in Nature and that they are the limitations of the general relativity. In the absence of a welldefined quantum gravity, models of regular black holes have been studied. We employ a probability distribution inspired mass function m(r) to replace the Kerr black hole mass M to represent a nonsingular rotating black hole that is identified asymptotically (r >> k, k > 0 constant) exactly as the Kerr-Newman black hole, and as the Kerr black hole when k = 0. The radiating counterpart renders a nonsingular generalization of Carmeli's spacetime as well as Vaidya's spacetime, in the appropriate limits. The exponential correction factor changing the geometry of the classical black hole to remove the curvature singularity can also be motivated by quantum arguments. The regular rotating spacetime can also be understood as a black hole of general relativity coupled to nonlinear electrodynamics. (orig.)
Quantum tunneling from scalar fields in rotating black strings
Gohar, H
2011-01-01
Using the Hamilton-Jacobi method of quantum tunneling and complex path integration, we study Hawking radiation of scalar particles from rotating black strings. We discuss tunneling of both charged and uncharged scalar particles from the event horizons. For this purpose, we use the Klein-Gordon equation and find the tunneling probability of outging scalar particles. The procedure gives Hawking temperature for rotating charged black strings as well.
Quantum tunneling from scalar fields in rotating black strings
Gohar, H.; Saifullah, K.
2013-08-01
Using the Hamilton-Jacobi method of quantum tunneling and complex path integration, we study Hawking radiation of scalar particles from rotating black strings. We discuss tunneling of both charged and uncharged scalar particles from the event horizons. For this purpose, we use the Klein-Gordon equation and find the tunneling probability of outgoing scalar particles. The procedure gives Hawking temperature for rotating charged black strings as well.
Coalescence of Rotating Black Holes on Eguchi-Hanson Space
Matsuno, Ken; Kimura, Masashi; Tomizawa, Shinya
2007-01-01
We obtain new charged rotating multi-black hole solutions on the Eguchi-Hanson space in the five-dimensional Einstein-Maxwell system with a Chern-Simons term and a positive cosmological constant. In the two-black holes case, these solutions describe the coalescence of two rotating black holes with the spatial topologies of S^3 into a single rotating black hole with the spatial topology of the lens space S^3/Z_2. We discuss the differences in the horizon areas between our solutions and the two-centered Klemm-Sabra solutions which describe the coalescence of two rotating black holes with the spatial topologies of S^3 into a single rotating black hole with the spatial topology of S^3.
On Hawking Radiation of 3D Rotating Hairy Black Holes
Belhaj, A.; Chabab, M.; Moumni, H. EL; Masmar, K.; Sedra, M. B.
2015-01-01
We study the Hawking radiation of 3D rotating hairy black holes. More concretely, we compute the transition probability of a bosonic and fermionic particle in such backgrounds. Thew, we show that the transition probability is independent of the nature of the particle. It is observed that the charge of the scalar hair B and the rotation parameter a control such a probability.
International Nuclear Information System (INIS)
We show that one may pass from bulk to boundary thermodynamic quantities for rotating anti-de Sitter (AdS) black holes in arbitrary dimensions so that if the bulk quantities satisfy the first law of thermodynamics then so do the boundary conformal field theory (CFT) quantities. This corrects recent claims that boundary CFT quantities satisfying the first law may only be obtained using bulk quantities measured with respect to a certain frame rotating at infinity, and which therefore do not satisfy the first law. We show that the bulk black-hole thermodynamic variables, or equivalently therefore the boundary CFT variables, do not always satisfy a Cardy-Verlinde type formula, but they do always satisfy an AdS-Bekenstein bound. The universal validity of the Bekenstein bound is a consequence of the more fundamental cosmic-censorship bound, which we find to hold in all cases examined. We also find that at fixed entropy, the temperature of a rotating black hole is bounded above by that of a nonrotating black hole, in four and five dimensions, but not in six or more dimensions. We find evidence for universal upper bounds for the area of cosmological event horizons and black-hole horizons in rotating black-hole spacetimes with a positive cosmological constant
Stationary Scalar Clouds Around Rotating Black Holes
Hod, Shahar
2012-01-01
Motivated by novel results in the theory of wave dynamics in black-hole spacetimes, we analyze the dynamics of a massive scalar field surrounding a rapidly rotating Kerr black hole. In particular, we report on the existence of stationary (infinitely long-lived) regular field configurations in the background of maximally rotating black holes. The effective height of these scalar "clouds" above the central black hole is determined analytically. Our results support the possible existence of stat...
Stationary Scalar Clouds Around Rotating Black Holes
Hod, Shahar
2012-01-01
Motivated by novel results in the theory of wave dynamics in black-hole spacetimes, we analyze the dynamics of a massive scalar field surrounding a rapidly rotating Kerr black hole. In particular, we report on the existence of stationary (infinitely long-lived) regular field configurations in the background of maximally rotating black holes. The effective height of these scalar "clouds" above the central black hole is determined analytically. Our results support the possible existence of stationary scalar field dark matter distributions surrounding rapidly rotating black holes.
Rotating Black Holes and Coriolis Effect
Wu, Xiaoning; Yuan, Pei-Hung; Cho, Chia-Jui
2015-01-01
In this work, we consider the fluid/gravity correspondence for general rotating black holes. By using the Petrov-like boundary condition in near horizon limit, we study the correspondence between gravitational perturbation and fluid equation. We find that the dual fluid equation for rotating black holes contains a Coriolis force term, which is closely related to the angular velocity of the black hole horizon. This can be seen as a dual effect for the frame-dragging effect of rotating black hole under the holographic picture.
Horizon structure of rotating Bardeen black hole and particle acceleration
International Nuclear Information System (INIS)
We investigate the horizon structure and ergosphere in a rotating Bardeen regular black hole, which has an additional parameter (g) due to the magnetic charge, apart from the mass (M) and the rotation parameter (a). Interestingly, for each value of the parameter g, there exists a critical rotation parameter (a = aE), which corresponds to an extremal black hole with degenerate horizons, while for a < aE it describes a non-extremal black hole with two horizons, and no black hole for a > aE. We find that the extremal value aE is also influenced by the parameter g, and so is the ergosphere. While the value of aE remarkably decreases when compared with the Kerr black hole, the ergosphere becomes thicker with the increase in g.We also study the collision of two equal mass particles near the horizon of this black hole, and explicitly show the effect of the parameter g. The center-of-mass energy (ECM) not only depend on the rotation parameter a, but also on the parameter g. It is demonstrated that the ECM could be arbitrarily high in the extremal cases when one of the colliding particles has a critical angular momentum, thereby suggesting that the rotating Bardeen regular black hole can act as a particle accelerator. (orig.)
Horizon structure of rotating Bardeen black hole and particle acceleration
Energy Technology Data Exchange (ETDEWEB)
Ghosh, Sushant G. [Jamia Millia Islamia, Centre for Theoretical Physics, New Delhi (India); University of KwaZulu-Natal, Astrophysics and Cosmology Research Unit, School of Mathematics, Statistics and Computer Science, Durban (South Africa); Amir, Muhammed [Jamia Millia Islamia, Centre for Theoretical Physics, New Delhi (India)
2015-11-15
We investigate the horizon structure and ergosphere in a rotating Bardeen regular black hole, which has an additional parameter (g) due to the magnetic charge, apart from the mass (M) and the rotation parameter (a). Interestingly, for each value of the parameter g, there exists a critical rotation parameter (a = a{sub E}), which corresponds to an extremal black hole with degenerate horizons, while for a < a{sub E} it describes a non-extremal black hole with two horizons, and no black hole for a > a{sub E}. We find that the extremal value a{sub E} is also influenced by the parameter g, and so is the ergosphere. While the value of a{sub E} remarkably decreases when compared with the Kerr black hole, the ergosphere becomes thicker with the increase in g.We also study the collision of two equal mass particles near the horizon of this black hole, and explicitly show the effect of the parameter g. The center-of-mass energy (E{sub CM}) not only depend on the rotation parameter a, but also on the parameter g. It is demonstrated that the E{sub CM} could be arbitrarily high in the extremal cases when one of the colliding particles has a critical angular momentum, thereby suggesting that the rotating Bardeen regular black hole can act as a particle accelerator. (orig.)
Energetic Gamma Radiation from Rapidly Rotating Black Holes
Hirotani, Kouichi
2015-01-01
Supermassive black holes are believed to be the central power house of active galactic nuclei. Applying the pulsar outer-magnetospheric particle accelerator theory to black-hole magnetospheres, we demonstrate that an electric field is exerted along the magnetic field lines near the event horizon of a rotating black hole. In this particle accelerator (or a gap), electrons and positrons are created by photon-photon collisions and accelerated in the opposite directions by this electric field, efficiently emitting gamma-rays via curvature and inverse-Compton processes. It is shown that a gap arises around the null charge surface formed by the frame-dragging effect, provided that there is no current injection across the gap boundaries. The gap is dissipating a part of the hole's rotational energy, and the resultant gamma-ray luminosity increases with decreasing plasma accretion from the surroundings. Considering an extremely rotating supermassive black hole, we show that such a gap reproduces the significant very-...
Angular Momentum-Free of the Entropy Relations for Rotating Kaluza-Klein Black Holes
Liu, Hang; Meng, Xin-He
2016-01-01
Based on a mathematical lemma related to the Vandermonde determinant and two theorems derived from the first law of black hole thermodynamics, we investigate the angular momentum independence of the entropy sum as well as the entropy product of general rotating Kaluza-Klein black holes in higher dimensions. We show that for both non-charged rotating Kaluza-Klein black holes and non-charged rotating Kaluza-Klein-AdS black holes, the angular momentum of the black holes will not be present in en...
Hawking radiation of scalars from accelerating and rotating black holes with NUT parameter
Jan, Khush; Gohar, H.
2014-03-01
We study the quantum tunneling of scalars from charged accelerating and rotating black hole with NUT parameter. For this purpose we use the charged Klein-Gordon equation. We apply WKB approximation and the Hamilton-Jacobi method to solve charged Klein-Gordon equation. We find the tunneling probability of outgoing charged scalars from the event horizon of this black hole, and hence the Hawking temperature for this black hole
Renormalized vacuum polarization of rotating black holes
Ferreira, Hugo R C
2015-01-01
Quantum field theory on rotating black hole spacetimes is plagued with technical difficulties. Here, we describe a general method to renormalize and compute the vacuum polarization of a quantum field in the Hartle-Hawking state on rotating black holes. We exemplify the technique with a massive scalar field on the warped AdS3 black hole solution to topologically massive gravity, a deformation of (2+1)-dimensional Einstein gravity. We use a "quasi-Euclidean" technique, which generalizes the Euclidean techniques used for static spacetimes, and we subtract the divergences by matching to a sum over mode solutions on Minkowski spacetime. This allows us, for the first time, to have a general method to compute the renormalized vacuum polarization (and, more importantly, the renormalized stress-energy tensor), for a given quantum state, on a rotating black hole, such as the physically relevant case of the Kerr black hole in four dimensions.
Renormalized vacuum polarization of rotating black holes
Ferreira, Hugo R. C.
2015-04-01
Quantum field theory on rotating black hole spacetimes is plagued with technical difficulties. Here, we describe a general method to renormalize and compute the vacuum polarization of a quantum field in the Hartle-Hawking state on rotating black holes. We exemplify the technique with a massive scalar field on the warped AdS3 black hole solution to topologically massive gravity, a deformation of (2 + 1)-dimensional Einstein gravity. We use a "quasi-Euclidean" technique, which generalizes the Euclidean techniques used for static spacetimes, and we subtract the divergences by matching to a sum over mode solutions on Minkowski spacetime. This allows us, for the first time, to have a general method to compute the renormalized vacuum polarization, for a given quantum state, on a rotating black hole, such as the physically relevant case of the Kerr black hole in four dimensions.
Spatial geometry of charged rotating and non-rotating rings in rotating and non-rotating frames
Romannikov, Alexander
2016-01-01
Spatial geometry of charged thin rotating and non-rotating rings in a rotating frame is investigated. It is shown, on an example of interaction between a charged probe and two positive charged non-rotating and negative charged rotating rings that the spatial geometry of the rotating ring in the rotating frame has to be different to the spatial geometry of the rotating frame. In the absent of direct relation between the spatial geometry rotating frame and the spatial geometry of the rotating ring in that frame the possibility of a non-flat spatial geometry of rotating electron rings in tokamak plasma is discussed.
Spatial geometry of charged rotating and non-rotating rings in rotating and non-rotating frames
Romannikov, Alexander
2016-01-01
Spatial geometry of charged thin rotating and non-rotating rings in a rotating frame is investigated. It is shown, on an example of interaction between a charged probe and two positive charged non-rotating and negative charged rotating rings that the spatial geometry of the rotating ring in the rotating frame has to be different to the spatial geometry of the rotating frame. In the absent of direct relation between the spatial geometry rotating frame and the spatial geometry of the rotating r...
Charge Fluctuations of an Uncharged Black Hole
Schiffer, Marcelo
2016-01-01
In this paper we calculate charge fluctuations of a Schwarzschild black-hole of mass $M$ confined within a perfectly reflecting cavity of radius R in thermal equilibrium with various species of radiation and fermions . Charge conservation is constrained by a Lagrange multiplier (the chemical potential). Black hole charge fluctuations are expected owing to continuous absorption and emission of particles by the black hole. For black holes much more massive than $10^{16} g$ , these fluctuations are exponentially suppressed. For black holes lighter than this, the Schwarzschild black hole is unstable under charge fluctuations for almost every possible size of the confining vessel. The stability regime and the fluctuations are calculated through the second derivative of the entropy with respect to the charge. The expression obtained contains many puzzling terms besides the expected thermodynamical fluctuations: terms corresponding to instabilities that do not depend on the specific value of charge of the charge car...
Twisting of light around rotating black holes
Tamburini, Fabrizio; Molina-Terriza, Gabriel; Anzolin, Gabriele; 10.1038/nphys1907
2011-01-01
Kerr black holes are among the most intriguing predictions of Einstein's general relativity theory. These rotating massive astrophysical objects drag and intermix their surrounding space and time, deflecting and phase-modifying light emitted nearby them. We have found that this leads to a new relativistic effect that imposes orbital angular momentum onto such light. Numerical experiments, based on the integration of the null geodesic equations of light from orbiting point-like sources in the Kerr black hole equatorial plane to an asymptotic observer, indeed identify the phase change and wavefront warping and predict the associated light-beam orbital angular momentum spectra. Setting up the best existing telescopes properly, it should be possible to detect and measure this twisted light, thus allowing a direct observational demonstration of the existence of rotating black holes. Since non-rotating objects are more an exception than a rule in the Universe, our findings are of fundamental importance.
Twisting of light around rotating black holes
Tamburini, Fabrizio; Thidé, Bo; Molina-Terriza, Gabriel; Anzolin, Gabriele
2011-03-01
Kerr black holes are among the most intriguing predictions of Einstein's general relativity theory. These rotating massive astrophysical objects drag and intermix their surrounding space and time, deflecting and phase-modifying light emitted near them. We have found that this leads to a new relativistic effect that imprints orbital angular momentum on such light. Numerical experiments, based on the integration of the null geodesic equations of light from orbiting point-like sources in the Kerr black hole equatorial plane to an asymptotic observer, indeed identify the phase change and wavefront warping and predict the associated light-beam orbital angular momentum spectra. Setting up the best existing telescopes properly, it should be possible to detect and measure this twisted light, thus allowing a direct observational demonstration of the existence of rotating black holes. As non-rotating objects are more an exception than a rule in the Universe, our findings are of fundamental importance.
Magnetospheres around rotating black holes
Czech Academy of Sciences Publication Activity Database
Dovčiak, Michal; Karas, V.
Singapor: World Scientific Publishing Co., 2003 - (Ruffini, R.; Sigismondi, C.), s. 288-295 [Nonlinear gravitodynamics. Rome (IT), 29.06.1998-04.07.1998] Institutional research plan: CEZ:AV0Z1003909 Keywords : black holes * general relativity Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics
Rotating black holes can have short bristles
International Nuclear Information System (INIS)
The elegant ‘no short hair’ theorem states that, if a spherically-symmetric static black hole has hair, then this hair must extend beyond 3/2 the horizon radius. In the present paper we provide evidence for the failure of this theorem beyond the regime of spherically-symmetric static black holes. In particular, we show that rotating black holes can support extremely short-range stationary scalar configurations (linearized scalar ‘clouds’) in their exterior regions. To that end, we solve analytically the Klein–Gordon–Kerr–Newman wave equation for a linearized massive scalar field in the regime of large scalar masses
Collision of two general particles around a rotating regular Hayward's black holes
Amir, Muhammed; Ghosh, Sushant G
2016-01-01
The rotating regular Hayward's spacetime, apart from mass ($M$) and angular momentum ($a$), has an additional deviation parameter ($g$) due to the magnetic charge, which generalizes the Kerr black hole when $g\
How fast can a black hole rotate?
Herdeiro, Carlos A R
2015-01-01
Kerr black holes have their angular momentum, $J$, bounded by their mass, $M$: $Jc\\leqslant GM^2$. There are, however, known black hole solutions violating this Kerr bound. We propose a very simple universal bound on the rotation, rather than on the angular momentum, of four-dimensional, stationary and axisymmetric, asymptotically flat black holes, given in terms of an appropriately defined horizon linear velocity, $v_H$. The $v_H$ bound is simply that $v_H$ cannot exceed the velocity of light. We verify the $v_H$ bound for known black hole solutions, including some that violate the Kerr bound, and conjecture that only extremal Kerr black holes saturate the $v_H$ bound.
Magnetic charge, black holes, and cosmic censorship
International Nuclear Information System (INIS)
The possibility of converting a Reissner-Nordstroem black hole into a naked singularity by means of test particle accretion is considered. The dually charged Reissner-Nordstroem metric describes a black hole only when M2>Q2+P2. The test particle equations of motion are shown to allow test particles with arbitrarily large magnetic charge/mass ratios to fall radially into electrically charged black holes. To determine the nature of the final state (black hole or naked singularity) an exact solution of Einstein's equations representing a spherical shell of magnetically charged dust falling into an electrically charged black hole is studied. Naked singularities are never formed so long as the weak energy condition is obeyed by the infalling matter. The differences between the spherical shell model and an infalling point test particle are examined and discussed
Angular Momentum-Free of the Entropy Relations for Rotating Kaluza-Klein Black Holes
Liu, Hang
2016-01-01
Based on a mathematical lemma related to the Vandermonde determinant and two theorems derived from the first law of black hole thermodynamics, we investigate the angular momentum independence of the entropy sum as well as the entropy product of general rotating Kaluza-Klein black holes in higher dimensions. We show that for both non-charged rotating Kaluza-Klein black holes and non-charged rotating Kaluza-Klein-AdS black holes, the angular momentum of the black holes will not be present in entropy sum relation in dimensions $d\\geq4$, while the independence of angular momentum of the entropy product holds provided that the black holes possess at least one zero rotation parameter $a_j$ = 0 in higher dimensions $d\\geq5$, which means that the cosmological constant does not affect the angular momentum-free property of entropy sum and entropy product under the circumstances that charge $\\delta=0$. For the reason that the entropy relations of charged rotating Kaluza-Klein black holes as well as the non-charged rotat...
Frame-Dragging from Charged Rotating Body
Dubey, Anuj Kumar
2016-01-01
In the present paper, we have considered the three parameters: mass, charge and rotation to discuss their combined effect on frame dragging for a charged rotating body. If we consider the ray of light which is emitted radially outward from a rotating body then the frame dragging shows a periodic nature with respect to coordinate $\\phi$ (azimuthal angle). It has been found that the value of frame dragging obtains a maximum at, $ \\phi =\\frac{\\pi}{2}$ and a minimum at $ \\phi =\\frac{3 \\pi}{2}$.
Black hole conserved charges in Generalized Minimal Massive Gravity
Directory of Open Access Journals (Sweden)
M.R. Setare
2015-05-01
Full Text Available In this paper we construct mass, angular momentum and entropy of black hole solution of Generalized Minimal Massive Gravity (GMMG in asymptotically Anti-de Sitter (AdS spacetimes. The Generalized Minimal Massive Gravity theory is realized by adding the CS deformation term, the higher derivative deformation term, and an extra term to pure Einstein gravity with a negative cosmological constant. We apply our result for conserved charge Qμ(ξ¯ to the rotating BTZ black hole solution of GMMG, and find energy, angular momentum and entropy. Then we show that our results for these quantities are consistent with the first law of black hole thermodynamics.
Charged Black Holes with Scalar Hair
Fan, Zhong-Ying
2015-01-01
We consider a class of Einstein-Maxwell-Dilaton theories, in which the dilaton coupling to the Maxwell field is not the usual single exponential function, but one with a stationary point. The theories admit two charged black holes: one is the Reissner-Nordstr\\o m (RN) black hole and the other has a varying dilaton. For a given charge, the new black hole in the extremal limit has the same AdS$_2\\times$Sphere near-horizon geometry as the RN black hole, but it carries larger mass. We then introduce some scalar potentials and obtain exact charged AdS black holes. We also generalize the results to black $p$-branes with scalar hair.
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.)
Hawking radiation from rotating brane black holes
Winstanley, Elizabeth(Consortium for Fundamental Physics, School of Mathematics and Statistics, University of Sheffield, Hicks Building, Hounsfield Road, Sheffield, S3 7RH, United Kingdom)
2007-01-01
We review recent work on the Hawking radiation of rotating brane black holes, as may be produced at the LHC. We outline the methodology for calculating the fluxes of particles, energy and angular momentum by spin-0, spin-1/2 and spin-1 quantum fields on the brane. We briefly review some of the key features of the emission, in particular the changes in the spectra as the number of extra dimensions or the angular velocity of the black hole increases. These quantities will be useful for accurate...
Rotating Dilaton Black Strings Coupled to Exponential Nonlinear Electrodynamics
Directory of Open Access Journals (Sweden)
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.
Rotating black hole solutions with quintessential energy
Toshmatov, Bobir; Ahmedov, Bobomurat
2015-01-01
Quintessential dark energy with density $\\rho$ and pressure $p$ is governed by an equation of state of the form $p=-\\omega_{q}\\rho$ with the quintessential parameter $\\omega_q\\in(-1;-1/3)$. We derive the geometry of quintessential rotating black holes, generalizing thus the Kerr spacetimes. Then we study the quintessential rotating black hole spacetimes with the special value of $\\omega_q = -2/3$ when the resulting formulae are simple and easily tractable. We show that such special spacetimes can exist for dimensionless quintessential parameter $c<1/6$ and determine the critical rotational parameter $a_0$ separating the black hole and naked singularity spacetime in dependence on the quintessential parameter $c$. For the spacetimes with $\\omega_q = 2/3$ we present the integrated geodesic equations in separated form and study in details the circular geodetical orbits. We give radii and parameters of the photon circular orbits, marginally bound and marginally stable orbits. We stress that the outer boundary o...
Energy extremum principle for charged black holes
Fraser, Scott; Funkhouser, Shaker Von Price
2015-11-01
For a set of N asymptotically flat black holes with arbitrary charges and masses, all initially at rest and well separated, we prove the following extremum principle: the extremal charge configuration (|qi|=mi for each black hole) can be derived by extremizing the total energy, for variations of the black hole apparent horizon areas, at fixed charges and fixed Euclidean separations. We prove this result through second order in an expansion in the inverse separations. If all charges have the same sign, this result is a variational principle that reinterprets the static equilibrium of the Majumdar-Papapetrou-Hartle-Hawking solution as an extremum of total energy, rather than as a balance of forces; this result augments a list of related variational principles for other static black holes, and is consistent with the independently known Bogomol'nyi-Prasad-Sommerfield (BPS) energy minimum.
Charged perfect fluid in rigid rotation
International Nuclear Information System (INIS)
This paper is a continuation of the work of Bonnor and Raychaudhuri on a charged dust distribution in rigid rotation in general relativity. Here the authors are concerned with the similar problem of a charged perfect fluid with nonvanishing pressure. As in Raychaudhuri's work, symmetry-independent reduction of Einstein--Maxwell equations is undertaken. Certain assumptions in Raychaudhuri's paper regarding the inheritance by the electromagnetic field of the symmetry resulting from the rigidity of the motion are justified
Charged black hole remnants at the LHC
International Nuclear Information System (INIS)
We investigate possible signatures of long-lived (or stable) charged black holes at the Large Hadron Collider. In particular, we find that black hole remnants are characterised by quite low speed. Due to this fact, the charged remnants could, in some cases, be very clearly distinguished from the background events, exploiting dE/dX measurements. We also compare the estimate energy released by such remnants with that of typical Standard Model particles, using the Bethe-Bloch formula. (orig.)
Charged Dilatonic Black Holes in Gravity's Rainbow
Hendi, S H; Panah, B Eslam; Panahiyan, S
2015-01-01
In this paper, we analyze charged dilatonic black holes in gravity's rainbow. We obtain metric functions and different thermodynamic quantities for these charged black holes in dilatonic gravity's rainbow. We demonstrate that first law of thermodynamics is valid for these solutions. We also investigate thermal stability of these solutions using canonical ensemble. Finally, we analyze the effect that the variation of different parameters has on the stability of these solutions.
Charged black hole remnants at the LHC
Alberghi, G. L.; Bellagamba, L.; Calmet, X.; Casadio, R.; Micu, O.
2013-06-01
We investigate possible signatures of long-lived (or stable) charged black holes at the Large Hadron Collider. In particular, we find that black hole remnants are characterised by quite low speed. Due to this fact, the charged remnants could, in some cases, be very clearly distinguished from the background events, exploiting dE/ dX measurements. We also compare the estimate energy released by such remnants with that of typical Standard Model particles, using the Bethe-Bloch formula.
Charged Black Hole Remnants at the LHC
Alberghi, G. L.; Bellagamba, L.; Calmet, X.; Casadio, R.; Micu, O.
2013-01-01
We investigate possible signatures of long-lived (or stable) charged black holes at the Large Hadron Collider. In particular, we find that black hole remnants are characterised by quite low speed. Due to this fact, the charged remnants could, in some cases, be very clearly distinguished from the background events, exploiting dE/dX measurements. We also compare the estimate energy released by such remnants with that of typical Standard Model particles, using the Bethe-Bloch formula.
Formation and Evaporation of Charged Black Holes
Sorkin, Evgeny; Piran, Tsvi
2001-01-01
We investigate the dynamical formation and evaporation of a spherically symmetric charged black hole. We study the self-consistent one loop order semiclassical back-reaction problem. To this end the mass-evaporation is modeled by an expectation value of the stress-energy tensor of a neutral massless scalar field, while the charge is not radiated away. We observe the formation of an initially non extremal black hole which tends toward the extremal black hole $M=Q$, emitting Hawking radiation. ...
Magnetically Charged Black Holes and their Stability
Aichelburg, P C; Aichelburg, Peter C.; Bizon, Piotr
1993-01-01
We study magnetically charged black holes in the Einstein-Yang-Mills-Higgs theory in the limit of infinitely strong coupling of the Higgs field. Using mixed analytical and numerical methods we give a complete description of static spherically symmetric black hole solutions, both abelian and nonabelian. In particular, we find a new class of extremal nonabelian solutions. We show that all nonabelian solutions are stable against linear radial perturbations. The implications of our results for the semiclassical evolution of magnetically charged black holes are discussed.
Noncommutative Geometry Inspired Rotating Black Hole in Three Dimensions
Tejeiro, Juan Manuel; Larranaga, Alexis
2010-01-01
We find a new rotating black hole in three-dimensional anti-de Sitter space using an anisotropic perfect fluid inspired by the noncommutative black hole. We deduce the thermodynamical quantities of this black hole and compare them with those of a rotating BTZ solution.
Noncommutative geometry-inspired rotating black hole in three dimensions
Tejeiro, Juan Manuel; Larrañaga, Alexis
2012-01-01
We find a new rotating black hole in three-dimensional anti-de Sitter space using an anisotropic perfect fluid inspired by the noncommutative black hole. We deduce the thermodynamical quantities of this black hole and compare them with those of a rotating BTZ solution.
Black diholes with unbalanced magnetic charges
Liang, Y C; Teo, Edward
2001-01-01
We present a technique that can be used to generate a static, axisymmetric solution of the Einstein-Maxwell-Dilaton equations from a stationary, axisymmetric solution of the vacuum Einstein equations. Starting from the Kerr solution, Davidson and Gedalin have previously made use of this technique to obtain a pair of oppositely charged, extremal dilatonic black holes, known as a black dihole. In this paper, we shall instead start from the Kerr-NUT solution. It will be shown that the new solution can also be interpreted as a dihole, but with the black holes carrying unbalanced magnetic charges. The effect of the NUT-parameter is to introduce a net magnetic charge into the system. Finally, we uplift our solution to ten dimensions to describe a system consisting of D6 and anti-D6-branes with unbalanced charges. The limit in which they coincide agrees with a solution recently derived by Brax et al..
Hydrodynamics and Elasticity of Charged Black Branes
DEFF Research Database (Denmark)
Gath, Jakob
-order corrected dynamics of uid branes carrying higher-form charge by obtaining the general form of their equations of motion to pole-dipole order in the absence of external forces. To monopole order, we characterize the corresponding effective theory of viscous uid branes by writing down the general form...... of the first-order dissipative corrections in terms of the shear and bulk viscosities as well as the transport coefficient associated with charge di usion. To dipole order, we furthermore, applying linear response theory, characterize the corresponding effective theory of stationary bent charged (an...... the first-order dispersion relations of the effective uid and analyze the dynamical stability of the black branes. We then focus on constructing stationary strained charged black brane solutions to rst order in a derivative expansion. Using solution generating techniques and the bent neutral black brane...
Five-dimensional rotating black hole in a uniform magnetic field: The gyromagnetic ratio
International Nuclear Information System (INIS)
In four-dimensional general relativity, the fact that a Killing vector in a vacuum spacetime serves as a vector potential for a test Maxwell field provides one with an elegant way of describing the behavior of electromagnetic fields near a rotating Kerr black hole immersed in a uniform magnetic field. We use a similar approach to examine the case of a five-dimensional rotating black hole placed in a uniform magnetic field of configuration with biazimuthal symmetry that is aligned with the angular momenta of the Myers-Perry spacetime. Assuming that the black hole may also possess a small electric charge we construct the five-vector potential of the electromagnetic field in the Myers-Perry metric using its three commuting Killing vector fields. We show that, like its four-dimensional counterparts, the five-dimensional Myers-Perry black hole rotating in a uniform magnetic field produces an inductive potential difference between the event horizon and an infinitely distant surface. This potential difference is determined by a superposition of two independent Coulomb fields consistent with the two angular momenta of the black hole and two nonvanishing components of the magnetic field. We also show that a weakly charged rotating black hole in five dimensions possesses two independent magnetic dipole moments specified in terms of its electric charge, mass, and angular momentum parameters. We prove that a five-dimensional weakly charged Myers-Perry black hole must have the value of the gyromagnetic ratio g=3
Charged Particles' Tunneling from Noncommutative Charged Black Hole
Mehdipour, S Hamid
2010-01-01
We apply the tunneling process of charged massive particles through the quantum horizon of a Reissner-Nordstr\\"om black hole in a new noncommutative gravity scenario. In this model, the tunneling amplitude on account of noncommutativity influences in the context of coordinate coherent states is modified. Our calculation points out that the emission rate satisfies the first law of black hole thermodynamics and is consistent with an underlying unitary theory.
Charged particles' tunneling from a noncommutative charged black hole
Mehdipour, S. Hamid
2010-01-01
We apply the tunneling process of charged massive particles through the quantum horizon of a Reissner-Nordstrom black hole in a new noncommutative gravity scenario. In this model, the tunneling amplitude on account of noncommutativity influences in the context of coordinate coherent states is modified. Our calculation points out that the emission rate satisfies the first law of black hole thermodynamics and is consistent with an underlying unitary theory.
Collisions of oppositely charged black holes
Zilhão, Miguel; Herdeiro, Carlos; Lehner, Luis; Sperhake, Ulrich
2013-01-01
The first fully non-linear numerical simulations of colliding charged black holes in D=4 Einstein-Maxwell theory were recently reported arXiv:1205.1063. These collisions were performed for black holes with equal charge-to-mass ratio, for which initial data can be found in closed analytic form. Here we generalize the study of collisions of charged black holes to the case of unequal charge-to-mass ratios. We focus on oppositely charged black holes, as to maximize acceleration-dependent effects. As |Q|/M increases from 0 to 0.99, we observe that the gravitational radiation emitted increases by a factor of ~ 2.7; the electromagnetic radiation emission becomes dominant for |Q|/M >~ 0.37 and at |Q|/M=0.99 is larger, by a factor of ~ 5.8, than its gravitational counterpart. We observe that these numerical results exhibit a precise and simple scaling with the charge. Furthermore, we show that the results from the numerical simulations are qualitatively captured by a simple analytic model that computes the electromagn...
Slowly rotating black holes in Einstein-æther theory
Barausse, Enrico; Sotiriou, Thomas P.; Vega, Ian
2016-02-01
We study slowly rotating, asymptotically flat black holes in Einstein-æther theory and show that solutions that are free from naked finite area singularities form a two-parameter family. These parameters can be thought of as the mass and angular momentum of the black hole, while there are no independent æ ther charges. We also show that the æ ther has nonvanishing vorticity throughout the spacetime, as a result of which there is no hypersurface that resembles the universal horizon found in static, spherically symmetric solutions. Moreover, for experimentally viable choices of the coupling constants, the frame-dragging potential of our solutions only shows percent-level deviations from the corresponding quantities in General Relativity and Hořava gravity. Finally, we uncover and discuss several subtleties in the correspondence between Einstein-æther theory and Hořava gravity solutions in the cω→∞ limit.
Charged dilatonic black holes in gravity's rainbow
Hendi, S. H.; Faizal, Mir; Panah, B. Eslam; Panahiyan, S.
2016-05-01
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.
Superradiance Instability of Small Rotating AdS Black Holes in Arbitrary Dimensions
Delice, Özgür
2015-01-01
We investigate the stability of $D$ dimensional singly rotating Myers-Perry-AdS black holes under superradiance against scalar field perturbations. It is well known that small four dimensional rotating or charged AdS black holes are unstable against superradiance instability of a scalar field. Recent works extended the existence of this instability to five dimensional rotating charged AdS black holes or static charged AdS Black holes in arbitrary dimensions. In this work we analytically prove that, rotating small AdS black holes in arbitrary dimensions also show superradiance instability irrespective of the value of the (positive) angular momentum quantum number. To do this we solve the Klein-Gordon equation in the slow rotation, low frequency limit. By using the asymptotic matching technique, we are able to calculate the real and imaginary parts of the correction terms to the frequency of the scalar field due to the presence of the black hole, confirming the presence of superradiance instability. We see that...
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.
Another new form of the rotating squashed black hole solution and its thermodynamics
Zhu, Xiao-Dan; Wu, Shuang-Qing; Yang, Shu-Zheng
2016-01-01
In a previous work, we had obtained a new simple form for the five-dimensional rotating squashed black hole solution by solving directly the vacuum Einstein field equations. In this paper, using a different metric ansatz, we have obtained another new but relatively simple form for the rotating uncharged black hole with squashed horizons. We then found its relation to our previous solution and investigated its thermodynamics by means of the counterterm method. Compared with the previous results given by the other author, both of our new metric forms and their associated thermodynamic expressions of the neutral rotating squashed black hole solution are very concise and elegant. Our work serves as a warmup excises for studying the rotating charged squashed black holes in the next step.
Stability of the extremal Reissner-Nordström black hole to charged scalar perturbations
International Nuclear Information System (INIS)
The stability of Reissner-Nordström 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-Nordström 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-Nordström 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-Nordström black holes, the two conditions which are required in order to trigger a possible superradiant instability [namely: (1) the existence of a trapping potential well outside the black hole, and (2) superradiant amplification of the trapped modes] cannot be satisfied simultaneously. Our results thus support the stability of extremal Reissner-Nordström black holes to charged scalar perturbations.
CFTs in rotating black hole backgrounds
Figueras, Pau; Tunyasuvunakool, Saran
2013-06-01
We use AdS/CFT to construct the gravitational dual of a 5D CFT in the background of a non-extremal rotating black hole. Our boundary conditions are such that the vacuum state of the dual CFT corresponds to the Unruh state. We extract the expectation value of the stress tensor of the dual CFT using holographic renormalization and show that it is stationary and regular on both the future and the past event horizons. The energy density of the CFT is found to be negative everywhere in our domain and we argue that this can be understood as a vacuum polarization effect. We construct the solutions by numerically solving the elliptic Einstein-DeTurck equation for stationary Lorentzian spacetimes with Killing horizons. Communicated by H Reall
CFTs in rotating black hole backgrounds
International Nuclear Information System (INIS)
We use AdS/CFT to construct the gravitational dual of a 5D CFT in the background of a non-extremal rotating black hole. Our boundary conditions are such that the vacuum state of the dual CFT corresponds to the Unruh state. We extract the expectation value of the stress tensor of the dual CFT using holographic renormalization and show that it is stationary and regular on both the future and the past event horizons. The energy density of the CFT is found to be negative everywhere in our domain and we argue that this can be understood as a vacuum polarization effect. We construct the solutions by numerically solving the elliptic Einstein–DeTurck equation for stationary Lorentzian spacetimes with Killing horizons. Communicated by H Reall (paper)
Statistical entropy of a charged black hole
International Nuclear Information System (INIS)
By using the method of quantum statistics, it is derived directly the partition functions of the bosonic and the fermionic field in the charged-black-hole space-time. The statistical entropy of a black-hole is obtained by an improved brick wall method. When it is chosen a proper parameter in these results, it can be obtained that the entropy of a black-hole is proportional to the area of the horizon. In the results, the neglected term and the divergent logarithmic term given in the original brick wall method do no exist. It is avoided the difficulty in solving the wave equation of the scalar and Dirac fields, and offer a simple and direct way of studying the entropy of the black hole
Statistical description of rotating Kaluza-Klein black holes
International Nuclear Information System (INIS)
We extend the recent microscopic analysis of extremal dyonic Kaluza-Klein (D0-D6) black holes to cover the regime of fast rotation in addition to slow rotation. Fastly rotating black holes, in contrast to slow ones, have nonzero angular velocity and possess ergospheres, so they are more similar to the Kerr black hole. The D-brane model reproduces their entropy exactly, but the mass gets renormalized from weak to strong coupling, in agreement with recent macroscopic analyses of rotating attractors. We discuss how the existence of the ergosphere and superradiance manifest themselves within the microscopic model. In addition, we show in full generality how Myers-Perry black holes are obtained as a limit of Kaluza-Klein black holes, and discuss the slow and fast rotation regimes and superradiance in this context
Noncommutative geometry-inspired rotating black hole in three dimensions
Indian Academy of Sciences (India)
Juan Manuel Tejeiro; Alexis Larrañaga
2012-01-01
We ﬁnd a new rotating black hole in three-dimensional anti-de Sitter space using an anisotropic perfect ﬂuid inspired by the noncommutative black hole. We deduce the thermodynamical quantities of this black hole and compare them with those of a rotating BTZ solution and give corrections to the area law to get the exact nature of the Bekenstein–Hawking entropy.
Massive Vector Particles Tunneling From Noncommutative Charged Black Holes
Övgün, Ali
2015-01-01
In this paper, we investigate the tunneling process of charged massive bosons $W^{\\pm}$ (spin-1 particles) from noncommutative charged black holes such as charged RN black holes and charged BTZ black holes. By applying the WKB approximation and by using the Hamilton-Jacobi equation we derive the tunneling rate and the corresponding Hawking temperature for those black holes configuration. The tunneling rate shows that the radiation deviates from pure thermality and is consistent with an underlying unitary theory.
Charged quantum black holes: thermal stability criterion
International Nuclear Information System (INIS)
A criterion of thermal stability is derived for electrically charged quantum black holes having a large horizon area (compared to the Planck area), as an inequality between the mass of the black hole and its microcanonical entropy. The derivation is based on the key results of loop quantum gravity and equilibrium statistical mechanics of a grand canonical ensemble, with Gaussian fluctuations around an equilibrium thermal configuration assumed here to be a quantum isolated horizon. No aspect of classical black hole geometry is used to deduce the stability criterion. Since no particular form of the mass function is used a priori, our stability criterion provides a platform to test the thermal stability of a black hole with a given mass function. The mass functions of the two most familiar charged black hole solutions are tested as a fiducial check. We also discuss the validity of the saddle-point approximation used to incorporate thermal fluctuations. Moreover, the equilibrium Hawking temperature is shown to have an additional quantum correction over the semiclassical value. (paper)
A twist in the geometry of rotating black holes: seeking the cause of acausality
Andreka, Hajnal; Wuthrich, Christian
2007-01-01
We investigate Kerr-Newman black holes in which a rotating charged ring-shaped singularity induces a region which contains closed timelike curves (CTCs). Contrary to popular belief, it turns out that the time orientation of the CTC is opposite to the direction in which the singularity or the ergosphere rotates. In this sense, CTCs "counter-rotate" against the rotating black hole. We have similar results for all spacetimes sufficiently familiar to us in which rotation induces CTCs. This motivates our conjecture that perhaps this counter-rotation is not an accidental oddity particular to Kerr-Newman spacetimes, but instead there may be a general and intuitively comprehensible reason for this.
Three Dimensional Charged Black Hole Inspired by Noncommutative Geometry
Larranaga, Alexis
2010-01-01
We find a new charged black hole in three-dimensional anti-de Sitter space using an anisotropic perfect fluid inspired by the noncommutative black hole as the source of matter and a gaussian distribution of electric charge. We deduce the thermodynamical quantities of this black hole and compare them with those of a charged BTZ solution.
Canonical Entropy and Phase Transition of Rotating Black Hole
Institute of Scientific and Technical Information of China (English)
ZHAO Ren; WU Yue-Qin; ZHANG Li-Chun
2008-01-01
Recently, the Hawking radiation of a black hole has been studied using the tunnel effect method. The radiation spectrum of a black hole is derived. By discussing the correction to spectrum of the rotating black hole, we obtain the canonical entropy. The derived canonical entropy is equal to the sum of Bekenstein-Hawking entropy and correction term. The correction term near the critical point is different from the one near others. This difference plays an important role in studying the phase transition of the black hole. The black hole thermal capacity diverges at the critical point. However, the canonical entropy is not a complex number at this point. Thus we think that the phase transition created by this critical point is the second order phase transition. The discussed black hole is a five-dimensional Kerr-AdS black hole. We provide a basis for discussing thermodynamic properties of a higher-dimensional rotating black hole.
Rational Orbits around Charged Black Holes
Misra, Vedant
2010-01-01
We show that all eccentric timelike orbits in Reissner-Nordstr\\"{o}m spacetime can be classified using a taxonomy that draws upon an isomorphism between periodic orbits and the set of rational numbers. By virtue of the fact that the rationals are dense, the taxonomy can be used to approximate aperiodic orbits with periodic orbits. This may help reduce computational overhead for calculations in gravitational wave astronomy. Our dynamical systems approach enables us to study orbits for both charged and uncharged particles in spite of the fact that charged particle orbits around a charged black hole do not admit a simple one-dimensional effective potential description. Finally, we show that comparing periodic orbits in the RN and Schwarzschild geometries enables us to distinguish charged and uncharged spacetimes by looking only at the orbital dynamics.
Hovering Black Holes from Charged Defects
Horowitz, Gary T; Santos, Jorge E; Way, Benson
2014-01-01
We construct the holographic dual of an electrically charged, localised defect in a conformal field theory at strong coupling, by applying a spatially dependent chemical potential. We find that the IR behaviour of the spacetime depends on the spatial falloff of the potential. Moreover, for sufficiently localized defects with large amplitude, we find that a new gravitational phenomenon occurs: a spherical extremal charged black hole nucleates in the bulk: a hovering black hole. This is a second order quantum phase transition. We construct this new phase with several profiles for the chemical potential and study its properties. We find an apparently universal behaviour for the entropy of the defect as a function of its amplitude. We comment on the possible field theory implications of our results.
Particles and scalar waves in noncommutative charged black hole spacetime
Bhar, Piyali; Rahaman, Farook; Biswas, Ritabrata(Indian Institute of Engineering Sceince and Technology Shibpur (Formerly, Bengal Engineering and Science University Shibpur), 711 013, Howrah, West Bengal, India); Mondal, U. F.
2015-01-01
In this paper we have discussed geodesics and the motion of test particle in the gravitational field of noncommutative charged black hole spacetime. The motion of massive and massless particle have been discussed seperately. A comparative study of noncommutative charged black hole and usual Reissner-Nordstrom black hole has been done. The study of effective potential has also been included. Finally, we have examined the scattering of scalar waves in noncommutative charged black hole spacetime.
Particles and Scalar Waves in Noncommutative Charged Black Hole Spacetime
Piyali, Bhar; Farook, Rahaman; Ritabrata, Biswas; U. F., Mondal
2015-07-01
In this paper we have discussed geodesics and the motion of test particle in the gravitational field of non-commutative charged black hole spacetime. The motion of massive and massless particle have been discussed seperately. A comparative study of noncommutative charged black hole and usual Reissner-Nordström black hole has been done. The study of effective potential has also been included. Finally, we have examined the scattering of scalar waves in noncommutative charged black hole spacetime.
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.)
Cosmic censorship of rotating Anti-de Sitter black hole
Gwak, Bogeun; Lee, Bum-Hoon
2016-02-01
We test the validity of cosmic censorship in the rotating anti-de Sitter black hole. For this purpose, we investigate whether the extremal black hole can be overspun by the particle absorption. The particle absorption will change the mass and angular momentum of the black hole, which is analyzed using the Hamilton-Jacobi equations consistent with the laws of thermodynamics. We have found that the mass of the extremal black hole increases more than the angular momentum. Therefore, the outer horizon of the black hole still exists, and cosmic censorship is valid.
Black hole solutions in Einstein-charged scalar field theory
Ponglertsakul, S.; Dolan, S.; Winstanley, E.
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.
New rotating non-extremal black holes in D=5 maximal gauged supergravity
Energy Technology Data Exchange (ETDEWEB)
Mei Jianwei [George P. and Cynthia W. Mitchell Institute for Fundamental Physics, Texas A and M University, College Station, TX 77843 (United States); Pope, C.N. [George P. and Cynthia W. Mitchell Institute for Fundamental Physics, Texas A and M University, College Station, TX 77843 (United States)], E-mail: pope@physics.tamu.edu
2007-12-13
We obtain new non-extremal rotating black hole solutions in maximal five-dimensional gauged supergravity. They are characterised by five parameters, associated with the mass, the two angular momenta, and two independently-specifiable charge parameters. Two of the three charges associated with the U(1){sup 3} Cartan subgroup of the SO(6) gauge group are equal, whilst the third can be independently specified. These new solutions generalise all the previously-known non-extremal rotating solutions in five-dimensional gauged supergravity with independent angular momenta. They describe regular black holes, provided the parameters lie in appropriate ranges so that naked singularities and closed-timelike curves (CTCs) are avoided. We also construct the BPS limit, and show that regular supersymmetric black holes or topological solitons arise if the parameters are further restricted in an appropriate manner.
New Rotating Non-Extremal Black Holes in D=5 Maximal Gauged Supergravity
Mei, Jianwei
2007-01-01
We obtain new non-extremal rotating black hole solutions in maximal five-dimensional gauged supergravity. They are characterised by five parameters, associated with the mass, the two angular momenta, and two independently-specifiable charge parameters. Two of the three charges associated with the U(1)^3 Cartan subgroup of the SO(6) gauge group are equal, whilst the third can be independently specified. These new solutions generalise all the previously-known rotating solutions in five-dimensional gauged supergravity with independent angular momenta. They describe regular black holes, provided the parameters lie in appropriate ranges so that naked singularities and closed-timelike curves (CTCs) are avoided. We also construct the BPS limit, and show that regular supersymmetric black holes or topological solitons arise if the parameters are further restricted in an appropriate manner.
Electromagnetic Excitation of Rotating Black Holes and Relativistic Jets
Burinskii, A.; E. Elizalde; Hildebrandt, S. R.; Magli, G.
2006-01-01
We show that electromagnetic excitations of rotating black holes can lead to the appearance of narrow singular beams which break up the black hole horizon forming a tube-like region which connects the interior and exterior. It is argued that this effect may be at the origin of jet formation.
Rotating black strings in $f(R)$-Maxwell theory
Sheykhi, A; 10.1088/0031-8949/87/04/045004
2013-01-01
In general, the field equations of $f(R)$ theory coupled to a matter field are very complicated and hence it is not easy to find exact analytical solutions. However, if one considers traceless energy-momentum tensor for the matter source as well as constant scalar curvature, one can derive some exact analytical solutions from $f(R)$ theory coupled to a matter field. In this paper, by assuming constant curvature scalar, we construct a class of charged rotating black string solutions in $f(R)$-Maxwell theory. We study the physical properties and obtain the conserved quantities of the solutions. The conserved and thermodynamic quantities computed here depend on function $f'(R_{0})$ and differ completely from those of Einstein theory in AdS spaces. Besides, unlike Einstein gravity, the entropy does not obey the area law. We also investigate the validity of the first law of thermodynamics as well as the stability analysis in the canonical ensemble, and show that the black string solutions are always thermodynamica...
Scale-Invariant Rotating Black Holes in Quadratic Gravity
Directory of Open Access Journals (Sweden)
Guido Cognola
2015-07-01
Full Text Available Black hole solutions in pure quadratic theories of gravity are interesting since they allow the formulation of a set of scale-invariant thermodynamics laws. Recently, we have proven that static scale-invariant black holes have a well-defined entropy, which characterizes equivalent classes of solutions. In this paper, we generalize these results and explore the thermodynamics of rotating black holes in pure quadratic gravity.
Shapes of rotating nonsingular black hole shadows
Amir, Muhammed; Ghosh, Sushant G.
2016-07-01
It is believed that curvature singularities are a creation of general relativity and, hence, in the absence of a quantum gravity, models of nonsingular black holes have received significant attention. We study the shadow (apparent shape), an optical appearance because of its strong gravitational field, cast by a nonsingular black hole which is characterized by three parameters, i.e., mass (M ), spin (a ), and a deviation parameter (k ). The nonsingular black hole under consideration is a generalization of the Kerr black hole that can be recognized asymptotically (r ≫k ,k >0 ) explicitly as the Kerr-Newman black hole, and in the limit k →0 as the Kerr black hole. It turns out that the shadow of a nonsingular black hole is a dark zone covered by a deformed circle. Interestingly, it is seen that the shadow of a black hole is affected due to the parameter k . Indeed, for a given a , the size of a shadow reduces as the parameter k increases, and the shadow becomes more distorted as we increase the value of the parameter k when compared with the analogous Kerr black hole shadow. We also investigate, in detail, how the ergoregion of a black hole is changed due to the deviation parameter k .
Scattering of particles by deformed non-rotating black holes
International Nuclear Information System (INIS)
We study the excitation of axial quasi-normal modes of deformed non-rotating black holes by test particles and we compare the associated gravitational wave signal with that expected in general relativity from a Schwarzschild black hole. Deviations from standard predictions are quantified by an effective deformation parameter, which takes into account deviations from both the Schwarzschild metric and the Einstein equations. We show that, at least in the case of non-rotating black holes, it is possible to test the metric around the compact object, in the sense that the measurement of the gravitational wave spectrum can constrain possible deviations from the Schwarzschild solution
Scattering of particles by deformed non-rotating black holes
Energy Technology Data Exchange (ETDEWEB)
Pei, Guancheng [Department of Physics, Center for Field Theory and Particle Physics, Fudan University, 200433, Shanghai (China); Bambi, Cosimo, E-mail: bambi@fudan.edu.cn [Department of Physics, Center for Field Theory and Particle Physics, Fudan University, 200433, Shanghai (China); Theoretical Astrophysics, Eberhard-Karls Universität Tübingen, 72076, Tübingen (Germany)
2015-11-27
We study the excitation of axial quasi-normal modes of deformed non-rotating black holes by test particles and we compare the associated gravitational wave signal with that expected in general relativity from a Schwarzschild black hole. Deviations from standard predictions are quantified by an effective deformation parameter, which takes into account deviations from both the Schwarzschild metric and the Einstein equations. We show that, at least in the case of non-rotating black holes, it is possible to test the metric around the compact object, in the sense that the measurement of the gravitational wave spectrum can constrain possible deviations from the Schwarzschild solution.
Scattering of particles by deformed non-rotating black holes
Energy Technology Data Exchange (ETDEWEB)
Pei, Guancheng [Fudan University, Department of Physics, Center for Field Theory and Particle Physics, Shanghai (China); Bambi, Cosimo [Fudan University, Department of Physics, Center for Field Theory and Particle Physics, Shanghai (China); Eberhard-Karls Universitaet Tuebingen, Theoretical Astrophysics, Tuebingen (Germany)
2015-11-15
We study the excitation of axial quasi-normal modes of deformed non-rotating black holes by test particles and we compare the associated gravitational wave signal with that expected in general relativity from a Schwarzschild black hole. Deviations from standard predictions are quantified by an effective deformation parameter, which takes into account deviations from both the Schwarzschild metric and the Einstein equations. We show that, at least in the case of non-rotating black holes, it is possible to test the metric around the compact object, in the sense that the measurement of the gravitational wave spectrum can constrain possible deviations from the Schwarzschild solution. (orig.)
Rotating Black Holes on Kaluza-Klein Bubbles
Tomizawa, S; Mishima, T; Iguchi, Hideo; Mishima, Takashi; Tomizawa, Shinya
2007-01-01
Using the solitonic solution generating techniques, we generate a new exact solution which describes a pair of rotating black holes on a Kaluza-Klein bubble as a vacuum solution in the five-dimensional Kaluza-Klein theory. We also investigate the properties of this solution. Two black holes with topology S^3 are rotating along the same direction and the bubble plays a role in holding two black holes. In static case, it coincides with the solution found by Elvang and Horowitz.
Rotating black strings in f(R)-Maxwell theory
Sheykhi, A.; Salarpour, S.; Bahrampour, Y.
2013-04-01
In general, the field equations of f(R) theory coupled to a matter field are very complicated and hence it is not easy to find exact analytical solutions. However, if one considers the traceless energy-momentum tensor for the matter source as well as constant scalar curvature, one can derive some exact analytical solutions from f(R) theory coupled to a matter field. In this paper, by assuming a constant curvature scalar, we construct a class of charged rotating black string solutions in f(R)-Maxwell theory. We study the physical properties and obtain the conserved quantities of the solutions. The conserved and thermodynamic quantities computed here depend on the function f‧(R0) and differ completely from those of Einstein theory in anti-de Sitter spaces. Besides, unlike Einstein gravity, the entropy does not obey the area law. We also investigate the validity of the first law of thermodynamics as well as the stability analysis in the canonical ensemble, and show that the black string solutions are always thermodynamically stable in f(R)-Maxwell theory with a constant curvature scalar. Finally, we extend the study to the case where the Ricci scalar is not a constant and in particular R = R(r). In this case, by using the Lagrangian multipliers method, we derive an analytical black string solution from f(R) gravity and reconstructed the function R(r). We find that this class of solutions has an additional logarithmic term in the metric function which incorporates the effect of the f(R) theory on the solutions.
Rotating black holes pierced by a cosmic string
Kubiznak, David
2015-01-01
A rotating black hole threaded by an infinitely long cosmic string is studied in the framework of the Abelian Higgs model. We show that contrary to a common belief in the presence of rotation the backreaction of the string does not induce a simple conical deficit. This leads to new distinct features of the Kerr--string system such as modified ISCO or shifted ergosphere, though these effects are most likely outside the range of observational precision. For an extremal rotating black hole, the system exhibits a first-order phase transition for the gravitational Meissner effect: small black holes exhibit a flux-expelled solution, with the gauge and scalar field remaining identically in their false vacuum state on the event horizon, whereas the horizon of large black holes is pierced by the vortex. A brief review prepared for the MG14 Proceedings.
Morozova, Viktoriya; Ahmedov, Bobomurat; Rezzolla, Luciano
2016-07-01
We extend the Wald solution for magnetic field to a black hole that is also moving at constant velocity. In particular, we derive analytic solutions for the Maxwell equations for a rotating black hole moving at constant speed in an asymptotically uniform magnetic test field. By adopting Kerr-Schild coordinates we avoid singular behaviors at the horizon and obtain a complete description of the charge and current distributions in terms of the black-hole spin and velocity. Using this solution, we compute the energy losses expected when charged particles are accelerated along the magnetic field lines, improving previous estimates that had to cope with singular electromagnetic fields on the horizon. When used to approximate the emission from binary black holes in a uniform magnetic field, our estimates match reasonably well those from numericalrelativity calculations in the force-free approximation.
Shapes of rotating nonsingular black hole shadows
Amir, Muhammed
2016-01-01
It is a belief that singularities are creation of general relativity and hence in the absence of a quantum gravity, models of nonsingular black hole have received significant attention. We study the shadow (apparent shape), an optical appearance because of its strong gravitational field, cast by a nonsingular black hole which is characterized by three parameters, i.e., mass ($M$), spin ($a$) and a deviation parameter ($k$). The nonsingular black hole, under consideration, is a generalization of the Kerr black hole can be recognized asymptotically ($r>>k, k>0$) explicitly as the Kerr\\(-\\)Newman black hole, and in the limit $k \\rightarrow 0$ as the Kerr black hole. It turns out that the shadow of a nonsingular black hole is a dark zone covered by deformed circle. Interestingly, it is seen that the shadow of a black hole is affected due to the parameter $k$. Indeed, for a given $a$, the size of a shadow reduces as the parameter $k$ increases and the shadow becomes more distorted as we increase the value of the p...
Geometric Product Formula for Charged Accelerating Black Hole
Pradhan, Parthapratim
2016-01-01
We evaluate the geometric product formula i.e. area (or entropy) product formula of outer horizon (${\\cal H}^{+}$) and inner horizon (${\\cal H}^{-}$) for charged accelerating black hole. We find that mass-independent area functional relation of ${\\cal H}^{\\pm}$ for this black hole in terms of black hole charge, acceleration, cosmological constant and \\emph{cosmic string tension} respectively. We also compute the \\emph{Penrose inequality} for this black hole. Finally we compute the specific heat for this BH to determine the local thermodynamic stability of this black hole. Under certain criterion the black hole displayed second order phase transition.
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.
Physics of Rotating and Expanding Black Hole Universe
Directory of Open Access Journals (Sweden)
Seshavatharam U. V. S.
2010-04-01
Full Text Available Throughout its journey universe follows strong gravity. By unifying general theory of relativity and quantum mechanics a simple derivation is given for rotating black hole's temperature. It is shown that when the rotation speed approaches light speed temperature approaches Hawking's black hole temperature. Applying this idea to the cosmic black hole it is noticed that there is "no cosmic temperature" if there is "no cosmic rotation". Starting from the Planck scale it is assumed that universe is a rotating and expanding black hole. Another key assumption is that at any time cosmic black hole rotates with light speed. For this cosmic sphere as a whole while in light speed rotation "rate of decrease" in temperature or "rate of increase" in cosmic red shift is a measure of "rate of cosmic expansion". Since 1992, measured CMBR data indicates that, present CMB is same in all directions equal to $2.726^circ$ K, smooth to 1 part in 100,000 and there is no continuous decrease! This directly indicates that, at present rate of decrease in temperature is practically zero and rate of expansion is practically zero. Universe is isotropic and hence static and is rotating as a rigid sphere with light speed. At present galaxies are revolving with speeds proportional to their distances from the cosmic axis of rotation. If present CMBR temperature is $2.726^circ$ K, present value of obtained angular velocity is $2.17 imes 10^{-18}$ rad/sec $cong$ 67 Km/sec$imes$Mpc. Present cosmic mass density and cosmic time are fitted with a $ln (volume ratio$ parameter. Finally it can be suggested that dark matter and dark energy are ad-hoc and misleading concepts.
Tomizawa, Shinya; Matsuno, Ken; Nakagawa, Toshiharu
2008-01-01
Applying squashing transformation to Kerr-Godel black hole solutions, we present a new type of a rotating Kaluza-Klein black hole solution to the five-dimensional Einstein-Maxwell theory with a Chern-Simon term. The new solutions generated via the squashing transformation have no closed timelike curve everywhere outside the black hole horizons. At the infinity, the metric asymptotically approaches a twisted S^1 bundle over a four-dimensional Minkowski space-time. One of the remarkable features is that the solution has two independent rotation parameters along an extra dimension associated with the black hole's rotation and the Godel's rotation. The space-time also admits the existence of two disconnected ergoregions, an inner ergoregion and an outer ergoregion. These two ergoregions can rotate in the opposite direction as well as in the same direction.
Mass of Rotating Black Holes in Gauged Supergravities
Chen, W; Pope, C N
2006-01-01
The masses of several recently-constructed rotating black holes in gauged supergravities, including the general such solution in minimal gauged supergravity in five dimensions, have until now been calculated only by integrating the first law of thermodynamics. In some respects it is more satisfactory to have a calculation of the mass that is based directly upon the integration of a conserved quantity derived from a symmetry principal. In this paper, we evaluate the masses for the newly-discovered rotating black holes using the conformal definition of Ashtekar, Magnon and Das (AMD), and show that the results agree with the earlier thermodynamic calculations. We also consider the Abbott-Deser (AD) approach, and show that this yields an identical answer for the mass of the general rotating black hole in five-dimensional minimal gauged supergravity. In other cases we encounter discrepancies when applying the AD procedure. We attribute these to ambiguities or pathologies of the chosen decomposition into background...
Charged black holes in generalized teleparallel gravity
International Nuclear Information System (INIS)
In this paper we investigate charged static black holes in 4D for generalized teleparallel models of gravity, based on torsion as the geometric object for describing gravity according to the equivalence principle. As a motivated idea, we introduce a set of non-diagonal tetrads and derive the full system of non linear differential equations. We prove that the common Schwarzschild gauge is applicable only when we study linear f(T) case. We reobtain the Reissner-Nordstrom-de Sitter (or RN-AdS) solution for the linear case of f(T) and perform a parametric cosmological reconstruction for two nonlinear models. We also study in detail a type of the no-go theorem in the framework of this modified teleparallel gravity
Charged black holes in generalized teleparallel gravity
Energy Technology Data Exchange (ETDEWEB)
Rodrigues, M.E. [Faculdade de Física, Universidade Federal do Pará, Belém, Pará, 66075–110 (Brazil); Houndjo, M.J.S.; Tossa, J. [Institut de Mathématiques et de Sciences Physiques (IMSP) - Porto-Novo, 01 BP 613 (Benin); Momeni, D.; Myrzakulov, R., E-mail: esialg@gmail.com, E-mail: sthoundjo@yahoo.fr, E-mail: joel.tossa@imsp-uac.org, E-mail: d.momeni@yahoo.com, E-mail: rmyrzakulov@gmail.com [Eurasian International Center for Theoretical Physics - Eurasian National University, Astana, 010008 (Kazakhstan)
2013-11-01
In this paper we investigate charged static black holes in 4D for generalized teleparallel models of gravity, based on torsion as the geometric object for describing gravity according to the equivalence principle. As a motivated idea, we introduce a set of non-diagonal tetrads and derive the full system of non linear differential equations. We prove that the common Schwarzschild gauge is applicable only when we study linear f(T) case. We reobtain the Reissner-Nordstrom-de Sitter (or RN-AdS) solution for the linear case of f(T) and perform a parametric cosmological reconstruction for two nonlinear models. We also study in detail a type of the no-go theorem in the framework of this modified teleparallel gravity.
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.
On the black hole limit of rotating discs and rings
Kleinwächter, Andreas; Meinel, Reinhard
2010-01-01
Solutions to Einstein's field equations describing rotating fluid bodies in equilibrium permit parametric (i.e. quasi-stationary) transitions to the extreme Kerr solution (outside the horizon). This has been shown analytically for discs of dust and numerically for ring solutions with various equations of state. From the exterior point of view, this transition can be interpreted as a (quasi) black hole limit. All gravitational multipole moments assume precisely the values of an extremal Kerr black hole in the limit. In the present paper, the way in which the black hole limit is approached is investigated in more detail by means of a parametric Taylor series expansion of the exact solution describing a rigidly rotating disc of dust. Combined with numerical calculations for ring solutions our results indicate an interesting universal behaviour of the multipole moments near the black hole limit.
GUP Assisted Hawking Radiation of Rotating Acoustic Black Holes
Sakalli, I; Jusufi, K
2016-01-01
Recent studies [J. Steinhauer, Nature Phys., $\\textbf{10}$, 864 (2014); Phys. Rev. D $\\textbf{92}$, 024043 (2015)] provide compelling evidences that Hawking radiation could be experimentally proven by using an analogue black hole. In this paper, taking this situation into account we study the quantum gravitational effects on the Hawking radiation of rotating acoustic black holes. For this purpose, we consider the generalized uncertainty principle (GUP) in the phenomenon of quantum tunneling. We firstly take the modified commutation relations into account to compute the GUP modified Hawking temperature when the massive scalar particles tunnel from this black hole. Then, we find a remarkably instructive expression for the GUP entropy to derive the quantum gravity corrected Hawking temperature of the rotating acoustic black hole.
Quantum effects near a charged black hole singularity
International Nuclear Information System (INIS)
In this paper, the authors present an investigation of the problem of quantum fluctuations near a charged black hole singularity. The authors show that quantum fluctuations do not vanish near the singularity leading to the conclusion that charged black hole singularities are unlikely to occur in nature. This result may be obvious but we derive it 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.
Physics of Rotating and Expanding Black Hole Universe
Directory of Open Access Journals (Sweden)
Seshavatharam U. V. S.
2010-04-01
Full Text Available Throughout its journey universe follows strong gravity. By unifying general theory of relativity and quantum mechanics a simple derivation is given for rotating black hole’s temperature. It is shown that when the rotation speed approaches light speed temperature approaches Hawking’s black hole temperature. Applying this idea to the cosmic black hole it is noticed that there is “no cosmic temperature” if there is “no cosmic rotation”. Starting from the Planck scale it is assumed that- universe is a rotating and expanding black hole. Another key assumption is that at any time cosmic black hole rotates with light speed. For this cosmic sphere as a whole while in light speed rotation “rate of decrease” in temperature or “rate of increase” in cosmic red shift is a measure of “rate of cosmic expansion”. Since 1992, measured CMBR data indicates that, present CMB is same in all directions equal to 2 : 726 K ; smooth to 1 part in 100,000 and there is no continuous decrease! This directly indicates that, at present rate of decrease in temperature is practically zero and rate of expansion is practically zero. Universe is isotropic and hence static and is rotating as a rigid sphere with light speed. At present galaxies are revolving with speeds proportional to their distances from the cosmic axis of rotation. If present CMBR temperature is 2 : 726 K, present value of obtained angular velocity is 2 : 17 10 Present cosmic mass density and cosmic time are fitted with a ln ( volume ratio parameter. Finally it can be suggested that dark matter and dark energy are ad-hoc and misleading concepts.
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.
Quantum backreaction on a rotating BTZ black hole
Casals, Marc; Martínez, Cristián; Zanelli, Jorge
2016-01-01
We investigate semiclassical backreaction on a rotating BTZ black hole geometry produced by a conformally coupled quantum scalar field. We obtain the backreacted metric in analytic form. This allows us to explore the quantum effects on various regions of relevance for a rotating black hole space-time. We find that for given values of mass and angular momentum, quantum effects lead to a growth of both the event horizon and the radius of the ergosphere, and to a reduction of the angular velocity, compared to the unperturbed values. Furthermore, quantum effects give rise to the formation of a curvature singularity at the Cauchy horizon but show no evidence of a superradiant instability.
Regular charged black hole construction in 2+1 dimensions
International Nuclear Information System (INIS)
It is well known that unlike its chargeless version the charged Banados–Teitelboim–Zanelli (BTZ) black hole solution in (2+1)-dimensional spacetime is singular. We construct a charged, regular extension of the BTZ black hole solution by employing nonlinear Born–Infeld electrodynamics, supplemented with the Hoffmann term and gluing different spacetimes. The role of the latter term is to divide spacetime in a natural way into two regions by a circle and eliminate the inner singularity. Thermodynamics of such a black hole is investigated by Kaluza–Klein reduction to the (1+1)-dimensional dilaton gravity. -- Highlights: ► We obtain an electrically charged regular black hole solution as an extension of the uncharged BTZ black hole. ► Geometrically we obtained a variety of black hole states. ► Thermodynamically these regular black holes are stable.
Rotating Hayward’s regular black hole as particle accelerator
Amir, Muhammed; Ghosh, Sushant(Centre for Theoretical Physics, Jamia Millia Islamia, New Delhi, 110025, India)
2015-01-01
Recently, Ban\\~{a}dos, Silk and West (BSW) demonstrated that the extremal Kerr black hole can act as a particle accelerator with arbitrarily high center-of-mass energy ($E_{CM}$) when the collision takes place near the horizon. The rotating Hayward's regular black hole, apart from Mass ($M$) and angular momentum ($a$), has a new parameter $g$ ($g>0$ is a constant) that provides a deviation from the Kerr black hole. We demonstrate that for each $g$, with $M=1$, there exist critical $a_{E}$ and...
Radiation spectrum of a high-dimensional rotating black hole
Institute of Scientific and Technical Information of China (English)
无
2010-01-01
This study extends the classical Damour-Ruffini method and discusses Hawking radiation in a (n + 4)-dimensional rotating black hole. Under the condition that the total energy and angular momentum of spacetime are conservative, but angular momentum a = J/M of unit mass of the black hole is variable, taking into consideration the reaction of the radiation of the particle to the spacetime, a new Tortoise coordinate transformation and discuss the black hole radiation spectrum is discussed. The radiation spectrum that satisfies the unitary principle in the general case is derived.
Late-time dynamics of rapidly rotating black holes
International Nuclear Information System (INIS)
We study the late-time behaviour of a dynamically perturbed rapidly rotating black hole. Considering an extreme Kerr black hole, we show that the large number of virtually undamped quasinormal modes (that exist for nonzero values of the azimuthal eigenvalue m) combine in such a way that the field (as observed at infinity) oscillates with an amplitude that decays as 1/t at late times. For a near extreme black hole, these modes, collectively, give rise to an exponentially decaying field which, however, is considerably 'long-lived'. Our analytic results are verified using numerical time-evolutions of the Teukolsky equation. Moreover, we argue that the physical mechanism behind the observed behaviour is the presence of a 'superradiance resonance cavity' immediately outside the black hole. We present this new feature in detail, and discuss whether it may be relevant for astrophysical black holes. (author)
Hidden conformal symmetry of rotating black holes in minimal five-dimensional gauged supergravity
International Nuclear Information System (INIS)
In the present paper we show that for a low frequency limit the wave equation of a massless scalar field in the background of nonextremal charged rotating black holes in five-dimensional minimal gauged and ungauged supergravity can be written as the Casimir of an SL(2,R) symmetry. Our result shows that the entropy of the black hole is reproduced by the Cardy formula. Also the absorption cross section is consistent with the finite temperature absorption cross section for a two-dimensional conformal field theory.
Transient Instability of Rapidly Rotating Black Holes
Gralla, Samuel E; Zimmerman, Peter
2016-01-01
We analytically study the linear response of a near-extremal Kerr black hole to external scalar, electromagnetic, and gravitational field perturbations. We show that the energy density, electromagnetic field strength, and tidal force experienced by infalling observers exhibit transient growth near the horizon. The growth lasts arbitrarily long in the extremal limit, reproducing the horizon instability of extremal Kerr. We explain these results in terms of near-horizon geometry and discuss potential astrophysical implications.
Decaying orbits near a rotating black hole
Czech Academy of Sciences Publication Activity Database
Pecháček, T.; Karas, Vladimír
Opava: Silesian University, 2004 - (Hledík, S.; Stuchlík, Z.), s. 147-150. (Publications of the Institute of Physics. 3). ISBN 80-7248-242-4. [RAGtime /4/5/. Opava (CZ), 14.10.2002-16.10.2002, 13.10.2003-15.10.2003] Institutional research plan: CEZ:AV0Z1003909 Keywords : black holes * accretion * relativity Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics
Horizon structure and shadow of rotating Einstein-Born-Infeld black holes
Atamurotov, Farruh
2016-07-01
We investigate the horizon structure of the rotating Einstein-Born-Infeld solution which goes over to the Einstein-Maxwell's Kerr-Newman solution as the Born-Infeld parameter goes to innity ( ! 1). We nd that for a given , mass M and charge Q, there exist critical spinning parameter aE and rEH, which corresponds to an extremal Einstein-Born-Infeld black hole with degenerate horizons, and aE decreases and rEH increases with increase in the Born-Infeld parameter . While a shadow as an optical appearance due to its strong gravitational eld. We also investigate the shadow cast by the rotating Einstein- Born-Infeld black hole and demonstrate that the null geodesic equations can be integrated that allows us to investigate the shadow cast by a black hole which is found to be a dark zone covered by a circle. Interestingly, the shadows of Einstein-Born-Infeld black hole is slightly smaller than for the Reissner-Nordstrom black hole which are concentric circles, for different values of the Born-Infeld parameter , whose radius decreases with increase in the value of parameter . The shadows for the rotating Einstein-Born-Infeld solution are also included.
Loop variables in the geometry of a rotating black string
De Carvalho, A M M; Furtado, C; Furtado, Claudio; Moraes, Fernando
2003-01-01
In this paper we analyze in the Wilson loop context the parallel transport of vectors and spinors around a closed loop in the background space-time of a rotating black string in order to classify its global properties. We also examine particular closed orbits in this space-time and verify the Mandelstam relations.
On the generalized second law for rotating black holes
International Nuclear Information System (INIS)
The generalized second law of thermodynamics for rotating black holes is reexamined in the superradiant range in order to take account of the contribution to the production of entropy coming from the semiclassical non-thermal emission. After including this new contribution, the validity of the law is proved by using statistical thermodynamics arguments. (orig.)
Dynamics of test particles in the five-dimensional, charged, rotating EMCS spacetime
Reimers, Stephan
2016-01-01
We derive the complete set of geodesic equations for massive and massless test particles of a five-dimensional, charged, rotating black hole solution of the Einstein-Maxwell-Chern-Simons field equations in five-dimensional minimal gauged supergravity and present their analytical solutions in terms of Weierstra{\\ss}' elliptic functions. We study the polar and radial motion, depending on the black hole and test particle parameters, and characterize the test particle motion qualitatively by the means of effective potentials. We use the analytical solutions in order to visualize the test particle motion by two- and three-dimensional plots.
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.
Hidden Symmetries of Higher-Dimensional Rotating Black Holes
Kubiznak, David
2008-01-01
In this thesis we study higher-dimensional rotating black holes. Such black holes are widely discussed in string theory and brane-world models at present. We demonstrate that even the most general known Kerr-NUT-(A)dS spacetime, describing the general rotating higher-dimensional asymptotically (anti) de Sitter black hole with NUT parameters, is in many aspects similar to its four-dimensional counterpart. Namely, we show that it admits a fundamental hidden symmetry associated with the principal conformal Killing-Yano tensor. Such a tensor generates towers of hidden and explicit symmetries. The tower of Killing tensors is responsible for the existence of irreducible, quadratic in momenta, conserved integrals of geodesic motion. These integrals, together with the integrals corresponding to the tower of explicit symmetries, make geodesic equations in the Kerr-NUT-(A)dS spacetime completely integrable. We further demonstrate that in this spacetime the Hamilton-Jacobi, Klein-Gordon, and stationary string equations ...
Analytic continuation of the rotating black hole state counting
Achour, Jibril Ben; Perez, Alejandro
2016-01-01
In loop quantum gravity, a spherical black hole can be described in terms of a Chern-Simons theory on a punctured 2-sphere. The sphere represents the horizon. The punctures are the edges of spin-networks in the bulk which cross the horizon and carry quanta of area. One can generalize this construction and model a rotating black hole by adding an extra puncture colored with the angular momentum J in the 2-sphere. We compute the entropy of rotating black holes in this model and study its semi-classical limit. After performing an analytic continuation which sends the Barbero-Immirzi parameter to +/- i, we show that the leading order term in the semi-classical expansion of the entropy reproduces the Bekenstein-Hawking law independently of the value of J.
Thermodynamics of rotating black holes and black rings: phase transitions and thermodynamic volume
Altamirano, Natacha; Mann, Robert B; Sherkatghanad, Zeinab
2014-01-01
In this review we summarize, expand, and set in context recent developments on the thermodynamics of black holes in extended phase space, where the cosmological constant is interpreted as thermodynamic pressure and treated as a thermodynamic variable in its own right. We specifically consider the thermodynamics of higher-dimensional rotating asymptotically flat and AdS black holes and black rings in a canonical (fixed angular momentum) ensemble. We plot the associated thermodynamic potential-the Gibbs free energy-and study its behaviour to uncover possible thermodynamic phase transitions in these black hole spacetimes. We show that the multiply-rotating Kerr-AdS black holes exhibit a rich set of interesting thermodynamic phenomena analogous to the "every day thermodynamics" of simple substances, such as reentrant phase transitions of multicomponent liquids, multiple first-order solid/liquid/gas phase transitions, and liquid/gas phase transitions of the Van der Waals type. Furthermore, the reentrant phase tran...
Dynamics of fast charged particle beam rotation in bended crystals
International Nuclear Information System (INIS)
Dynamics of fast charged particle beam rotation in a bended monocrystal is considered. Face and volume mechanisms of capture in channels are taken into account simultaneously in the model presented. Functions of distribution in transverse energies (φ) of channeled and dechanneled particles are obtained. Charge-energy ''scale invariance'' in ion channeling with charge Z in a bended crystal determined by scale parameter W=pv/Z (p and v are pulse and velocity local to transverse planes) follows from the model presented
Conserved charges and first law of thermodynamics for Kerr-de Sitter black holes
Hajian, Kamal
2016-08-01
Recently, a general method 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 holes. Furthermore, 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 holes.
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.
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.
Exploring the bulk of tidal charged micro-black holes
International Nuclear Information System (INIS)
We study the bulk corresponding to tidal charged brane-world black holes. We employ a propagating algorithm which makes use of the three-dimensional multipole expansion and analytically yields the metric elements as functions of the five-dimensional coordinates and of the Adler-Deser-Misner mass, tidal charge, and brane tension. Since the projected brane equations cannot determine how the charge depends on the mass, our main purpose is to select the combinations of these parameters for which black holes of microscopic size possess a regular bulk. Our results could, in particular, be relevant for a better understanding of TeV-scale black holes.
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.
Three-charge black holes on a circle
Energy Technology Data Exchange (ETDEWEB)
Harmark, Troels [Niels Bohr Institute, Blegdamsvej 17, 2100 Copenhagen Oe (Denmark); Obers, Niels A. [Niels Bohr Institute, Blegdamsvej 17, 2100 Copenhagen Oe (Denmark); Roenne, Peter B. [Niels Bohr Institute, Blegdamsvej 17, 2100 Copenhagen Oe (Denmark); Kristjansson, Kristjan R. [Nordita, Blegdamsvej 17, 2100 Copenhagen Oe (Denmark)
2007-01-15
We study phases of five-dimensional three-charge black holes with a circle in their transverse space. In particular, when the black hole is localized on the circle we compute the corrections to the metric and corresponding thermodynamics in the limit of small mass. When taking the near-extremal limit, this gives the corrections to the finite entropy of the extremal three-charge black hole as a function of the energy above extremality. For the partial extremal limit with two charges sent to infinity and one finite we show that the first correction to the entropy is in agreement with the microscopic entropy by taking into account that the number of branes shift as a consequence of the interactions across the transverse circle. Beyond these analytical results, we also numerically obtain the entire phase of non- and near-extremal three- and two-charge black holes localized on a circle. More generally, we find in this paper a rich phase structure, including a new phase of three-charge black holes that are non-uniformly distributed on the circle. All these three-charge black hole phases are found via a map that relates them to the phases of five-dimensional neutral Kaluza-Klein black holes.
Three-charge black holes on a circle
International Nuclear Information System (INIS)
We study phases of five-dimensional three-charge black holes with a circle in their transverse space. In particular, when the black hole is localized on the circle we compute the corrections to the metric and corresponding thermodynamics in the limit of small mass. When taking the near-extremal limit, this gives the corrections to the finite entropy of the extremal three-charge black hole as a function of the energy above extremality. For the partial extremal limit with two charges sent to infinity and one finite we show that the first correction to the entropy is in agreement with the microscopic entropy by taking into account that the number of branes shift as a consequence of the interactions across the transverse circle. Beyond these analytical results, we also numerically obtain the entire phase of non- and near-extremal three- and two-charge black holes localized on a circle. More generally, we find in this paper a rich phase structure, including a new phase of three-charge black holes that are non-uniformly distributed on the circle. All these three-charge black hole phases are found via a map that relates them to the phases of five-dimensional neutral Kaluza-Klein black holes
The compressibility of rotating black holes in D-dimensions
International Nuclear Information System (INIS)
Treating the cosmological constant as a pressure, in the context of black hole thermodynamics, a thermodynamic volume for the black hole can be defined as being the thermodynamic variable conjugate to the pressure, in the sense of a Legendre transform. The thermodynamic volume is explicitly calculated, as the Legendre transform of the pressure in the enthalpy, for a rotating asymptotically anti-de Sitter Myers–Perry black hole in D space-time dimensions. The volume obtained is shown to agree with previous calculations using the Smarr relation. The compressibility is calculated and shown to be non-negative and bounded. Taking the limit of zero cosmological constant, the compressibility of a rotating black hole in asymptotically flat space-times is determined and the corresponding speed of sound computed. The latter is bounded above and has an elegant expression purely in terms of the angular momenta, in the form of quartic and quadratic Casimirs of the rotation group, SO(D − 1). (paper)
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...
Beyond the singularity of the 2-D charged black hole
International Nuclear Information System (INIS)
Two dimensional charged black holes in string theory can be obtained as exact SL(2,R) x U(1)/U(1) quotient CFTs. The geometry of the quotient is induced from that of the group, and in particular includes regions beyond the black hole singularities. Moreover, wavefunctions in such black holes are obtained from gauge invariant vertex operators in the SL(2,R) CFT, hence their behavior beyond the singularity is determined. When the black hole is charged we find that the wavefunctions are smooth at the singularities. Unlike the uncharged case, scattering waves prepared beyond the singularity are not fully reflected; part of the wave is transmitted through the singularity. Hence, the physics outside the horizon of a charged black hole is sensitive to conditions set behind the past singularity. (author)
Direct imaging rapidly-rotating non-Kerr black holes
Energy Technology Data Exchange (ETDEWEB)
Bambi, Cosimo, E-mail: Cosimo.Bambi@physik.uni-muenchen.de [Arnold Sommerfeld Center for Theoretical Physics, Ludwig-Maximilians-Universitaet Muenchen, 80333 Munich (Germany); Caravelli, Francesco, E-mail: fcaravelli@perimeterinstitute.ca [Max Planck Institute for Gravitational Physics, Albert Einstein Institute, 14476 Golm (Germany); Department of Physics, University of Waterloo, Waterloo, Ontario N2L 3G1 (Canada); Perimeter Institute for Theoretical Physics, Waterloo, Ontario N2L 2Y5 (Canada); Modesto, Leonardo, E-mail: lmodesto@perimeterinstitute.ca [Perimeter Institute for Theoretical Physics, Waterloo, Ontario N2L 2Y5 (Canada)
2012-05-01
Recently, two of us have argued that non-Kerr black holes in gravity theories different from General Relativity may have a topologically non-trivial event horizon. More precisely, the spatial topology of the horizon of non-rotating and slow-rotating objects would be a 2-sphere, like in Kerr space-time, while it would change above a critical value of the spin parameter. When the topology of the horizon changes, the black hole central singularity shows up. The accretion process from a thin disk can potentially overspin these black holes and induce the topology transition, violating the Weak Cosmic Censorship Conjecture. If the astrophysical black hole candidates are not the black holes predicted by General Relativity, we might have the quite unique opportunity to see their central region, where classical physics breaks down and quantum gravity effects should appear. Even if the quantum gravity region turned out to be extremely small, at the level of the Planck scale, the size of its apparent image would be finite and potentially observable with future facilities.
Horizon structure of rotating Einstein-Born-Infeld black holes and shadow
Atamurotov, Farruh; Ghosh, Sushant G.; Ahmedov, Bobomurat
2016-05-01
We investigate the horizon structure of the rotating Einstein-Born-Infeld solution which goes over to the Einstein-Maxwell's Kerr-Newman solution as the Born-Infeld parameter goes to infinity (β → ∞). We find that for a given β , mass M, and charge Q, there exist a critical spinning parameter aE and rHE, which corresponds to an extremal Einstein-Born-Infeld black hole with degenerate horizons, and aE decreases and rHE increases with increase of the Born-Infeld parameter β , while ahole with outer and inner horizons. Similarly, the effect of β on the infinite redshift surface and in turn on the ergo-region is also included. It is well known that a black hole can cast a shadow as an optical appearance due to its strong gravitational field. We also investigate the shadow cast by the both static and rotating Einstein-Born-Infeld black hole and demonstrate that the null geodesic equations can be integrated, which allows us to investigate the shadow cast by a black hole which is found to be a dark zone covered by a circle. Interestingly, the shadow of an Einstein-Born-Infeld black hole is slightly smaller than for the Reissner-Nordstrom black hole, which consists of concentric circles, for different values of the Born-Infeld parameter β , whose radius decreases with increase of the value of the parameter β . Finally, we have studied observable distortion parameter for shadow of the rotating Einstein-Born-Infeld black hole.
Bounds on Photon Charge from Evaporation of Massive Black Holes
Sivaram, C; Arun, Kenath
2010-01-01
Photon charge has been of interest as a phenomenological testing ground for basic assumptions in fundamental physics. There have been several constraints on the photon charge based on very different considerations. In this paper we put further limits based on the well known properties of charged black holes and their subsequent evaporation by Hawking radiation and the assumption of charge conservation over this long physical process.
Charged scalar perturbations around a regular magnetic black hole
Huang, Yang; Liu, Dao-Jun
2016-05-01
We study charged scalar perturbations in the background of a regular magnetic black hole. In this case, the charged scalar perturbation does not result in superradiance. By using a careful time-domain analysis, we show that the charge of the scalar field can change the real part of the quasinormal frequency, but has little impact on the imaginary part of the quasinormal frequency and the behavior of the late-time tail. Therefore, the regular magnetic black hole may be stable under the perturbations of a charged scalar field at the linear level.
Black hole evaporation in a noncommutative charged Vaidya model
Energy Technology Data Exchange (ETDEWEB)
Sharif, M., E-mail: msharif.math@pu.edu.pk; Javed, W. [University of the Punjab, Department of Mathematics (Pakistan)
2012-06-15
We study the black hole evaporation and Hawking radiation for a noncommutative charged Vaidya black hole. For this purpose, we determine a spherically symmetric charged Vaidya model and then formulate a noncommutative Reissner-Nordstroem-like solution of this model, which leads to an exact (t - r)-dependent metric. The behavior of the temporal component of this metric and the corresponding Hawking temperature are investigated. The results are shown in the form of graphs. Further, we examine the tunneling process of charged massive particles through the quantum horizon. We find that the tunneling amplitude is modified due to noncommutativity. Also, it turns out that the black hole evaporates completely in the limits of large time and horizon radius. The effect of charge is to reduce the temperature from a maximum value to zero. We note that the final stage of black hole evaporation is a naked singularity.
Black Hole Evaporation in a Noncommutative Charged Vaidya Model
Sharif, M
2012-01-01
The aim of this paper is to study the black hole evaporation and Hawking radiation for a noncommutative charged Vaidya black hole. For this purpose, we determine spherically symmetric charged Vaidya model and then formulate a noncommutative Reissner-Nordstr$\\ddot{o}$m-like solution of this model which leads to an exact $(t-r)$ dependent metric. The behavior of temporal component of this metric and the corresponding Hawking temperature is investigated. The results are shown in the form of graphs. Further, we examine the tunneling process of the charged massive particles through the quantum horizon. It is found that the tunneling amplitude is modified due to noncommutativity. Also, it turns out that black hole evaporates completely in the limits of large time and horizon radius. The effect of charge is to reduce the temperature from maximum value to zero. It is mentioned here that the final stage of black hole evaporation turns out to be a naked singularity.
Black hole evaporation in a noncommutative charged Vaidya model
Sharif, M.; Javed, W.
2012-06-01
We study the black hole evaporation and Hawking radiation for a noncommutative charged Vaidya black hole. For this purpose, we determine a spherically symmetric charged Vaidya model and then formulate a noncommutative Reissner-Nordström-like solution of this model, which leads to an exact ( t - r)-dependent metric. The behavior of the temporal component of this metric and the corresponding Hawking temperature are investigated. The results are shown in the form of graphs. Further, we examine the tunneling process of charged massive particles through the quantum horizon. We find that the tunneling amplitude is modified due to noncommutativity. Also, it turns out that the black hole evaporates completely in the limits of large time and horizon radius. The effect of charge is to reduce the temperature from a maximum value to zero. We note that the final stage of black hole evaporation is a naked singularity.
Black hole evaporation in a noncommutative charged Vaidya model
International Nuclear Information System (INIS)
We study the black hole evaporation and Hawking radiation for a noncommutative charged Vaidya black hole. For this purpose, we determine a spherically symmetric charged Vaidya model and then formulate a noncommutative Reissner-Nordström-like solution of this model, which leads to an exact (t − r)-dependent metric. The behavior of the temporal component of this metric and the corresponding Hawking temperature are investigated. The results are shown in the form of graphs. Further, we examine the tunneling process of charged massive particles through the quantum horizon. We find that the tunneling amplitude is modified due to noncommutativity. Also, it turns out that the black hole evaporates completely in the limits of large time and horizon radius. The effect of charge is to reduce the temperature from a maximum value to zero. We note that the final stage of black hole evaporation is a naked singularity.
Black Hole Evaporation in a Noncommutative Charged Vaidya Model
Sharif, M.; Javed, Wajiha
2012-01-01
The aim of this paper is to study the black hole evaporation and Hawking radiation for a noncommutative charged Vaidya black hole. For this purpose, we determine spherically symmetric charged Vaidya model and then formulate a noncommutative Reissner-Nordstr$\\ddot{o}$m-like solution of this model which leads to an exact $(t-r)$ dependent metric. The behavior of temporal component of this metric and the corresponding Hawking temperature is investigated. The results are shown in the form of grap...
Effect of Thermal Fluctuations on a Charged Dilatonic Black Saturn
Behnam Pourhassan; Mir Faizal
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. ...
Effect of thermal fluctuations on a charged dilatonic black Saturn
Behnam Pourhassan; Mir Faizal
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. ...
Strong field gravitational lensing by a charged Galileon black hole
Zhao, Shan-Shan; Xie, Yi
2016-07-01
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 these observables for the closest supermassive black hole Sgr A*. The strong field lensing observables of the charged Galileon black hole can be close to those of a tidal Reissner-Nordström black hole or those of a Reissner-Nordström black hole. It will be helpful to distinguish these black holes if we can separate the outermost relativistic images and determine their angular separation, brightness difference and time delay, although it requires techniques beyond the current limit.
Rotating and accelerating black holes with cosmological constant
Chen, Yu; Ng, Cheryl; Teo, Edward
2016-01-01
We propose a new form of the rotating C-metric with cosmological constant, which generalises the form found by Hong and Teo for the Ricci-flat case. This solution describes the entire class of spherical black holes undergoing rotation and acceleration in dS or AdS space-time. The new form allows us to identify the complete ranges of coordinates and parameters of this solution. We perform a systematic study of its geometrical and physical properties, and of the various limiting cases that aris...
Rotating and accelerating black holes with cosmological constant
Chen, Yu; Teo, Edward
2016-01-01
We propose a new form of the rotating C-metric with cosmological constant, which generalises the form found by Hong and Teo for the Ricci-flat case. This solution describes the entire class of spherical black holes undergoing rotation and acceleration in dS or AdS space-time. The new form allows us to identify the complete ranges of coordinates and parameters of this solution. We perform a systematic study of its geometrical and physical properties, and of the various limiting cases that arise from it.
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.
Rotating Accretion Flows: From Infinity to the Black Hole
Li, Jason; Sunyaev, Rashid
2012-01-01
Accretion onto a supermassive black hole of a rotating inflow is a particularly difficult problem to study because of the wide range of length scales involved. There has been some analytic and numerical treatment of the global properties of accretion flows, but detailed numerical simulations are required to address certain critical aspects. We use the ZEUS code to run hydrodynamical simulations of rotating, axisymmetric accretion flows with Bremsstrahlung cooling, considering solutions with and without viscous angular momentum transport, and also electron thermal conduction. Infalling gas is followed from well beyond R_Bondi down to the vicinity of the black hole. Absent viscous transport, when the centrifugal balance radius significantly exceeds R_Schwarzschild, the accretion rate is zero and the flow approaches a stationary solution in which pressure impedes inflow from large radii. With viscosity, we find two general classes of solutions: low inflow rate, hot, vertically extended disks with very low accret...
On the Penrose process for rotating black holes
Heller, Leon
2009-01-01
Penrose described a process that, in principle, could extract energy and angular momentum from a rotating black hole. Here we examine two procedures that were claimed to be capable of implementing the Penrose idea; both make use of a particle moving at the horizon. In one, the particle is swallowed, and in the other the particle and black hole gradually exchange energy and angular momentum. We show that if the particle has negative energy and negative angular momentum but no radial momentum both procedures violate the requirement that the area of a black hole not decrease. For the gradual exchange method, however, it appears that the Penrose process could proceed if the particle has positive energy and angular momentum, but nevertheless removes energy from the black hole. It does not, however, lead to a Schwarzschild black hole. For an extreme Kerr black hole it's mass decreases by at most 9.7%, well short of the theoretical limit for a reversible process of 1-1/sqrt{2} =29%.
Conformal invariance and near-extreme rotating AdS black holes
International Nuclear Information System (INIS)
We obtain retarded Green's functions for massless scalar fields in the background of near-extreme, near-horizon rotating charged black holes of five-dimensional minimal gauged supergravity. The radial part of the (separable) massless Klein-Gordon equation in such general black hole backgrounds is Heun's equation, due to the singularity structure associated with the three black hole horizons. On the other hand, we find the scaling limit for the near-extreme, near-horizon background where the radial equation reduces to a hypergeometric equation whose SL(2,R)2 symmetry signifies the underlying two-dimensional conformal invariance, with the two sectors governed by the respective Frolov-Thorne temperatures.
Evaporation of charged black holes near extremality
Fabbri, A; Navarro, D. J.; Navarro-Salas, J.
2000-01-01
The AdS_2\\timesS^2 geometry of near-extremal Reissner-Nordstrom black holes can be described by an effective solvable model which allows to follow analytically the evaporation process including the backreaction. We find that an infinite amount of time is required for the black hole to decay to extremality.
Radiative Shocks in Rotating Accretion Flows around Black Holes
Okuda, T; Toscano, E; Molteni, D
2004-01-01
It is well known that the rotating accretion flows around black holes form shock waves close to the black holes, after the flow passes through the outer sonic point and can be virtually stopped by the centrifugal force. We examine numerically such shock waves in 1D and 2D accretion flows, taking account of the cooling and heating of gas and the radiation transport. The numerical results show that the shock location shifts outward compared with that in the adiabatic solutions and that the more rarefied ambient density leads to the more outward shock position. In the 2D-flow, we find an intermediate frequency QPO behavior of the shock location as is observed in the black hole candidate GRS 1915+105.
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.
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.``
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.
Inferring black hole charge from backscattered electromagnetic radiation
Crispino, Luís C B; Higuchi, Atsushi; de Oliveira, Ednilton S
2014-01-01
We compute the scattering cross section of Reissner-Nordstr\\"om black holes for the case of an incident electromagnetic wave. We describe how scattering is affected by both the conversion of electromagnetic to gravitational radiation, and the parity-dependence of phase shifts induced by the black hole charge. The latter effect creates a helicity-reversed scattering amplitude that is non-zero in the backward direction. We show that from the character of the electromagnetic wave scattered in the backward direction it is possible, in principle, to infer if a static black hole is charged.
Internal Structure of Charged AdS Black Holes
Bhattacharjee, Srijit(Astroparticle Physics & Cosmology Division, Saha Institute of Nuclear Physics, Kolkata, 700064, India); Sarkar, Sudipta; 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...
Oscillating supertubes and neutral rotating black hole microstates
International Nuclear Information System (INIS)
The construction of neutral black hole microstates is an important problem, with implications for the information paradox. In this paper we conjecture a construction of non-supersymmetric supergravity solutions describing D-brane configurations which carry mass and angular momentum, but no other conserved charges. We first study a classical string solution which locally carries dipole winding and momentum charges in two compact directions, but globally carries no net winding or momentum charge. We investigate its backreaction in the D1-D5 duality frame, where this object becomes a supertube which locally carries oscillating dipole D1-D5 and NS1-NS5 charges, and again carries no net charge. In the limit of an infinite straight supertube, we find an exact supergravity solution describing this object. We conjecture that a similar construction may be carried out based on a class of two-charge non-supersymmetric D1-D5 solutions. These results are a step towards demonstrating how neutral black hole microstates may be constructed in string theory
Oscillating supertubes and neutral rotating black hole microstates
Mathur, Samir D
2014-01-01
The construction of neutral black hole microstates is an important problem, with implications for the information paradox. In this paper we conjecture a construction of non-supersymmetric supergravity solutions describing D-brane configurations which carry mass and angular momentum, but no other conserved charges. We first study a classical string solution which locally carries dipole winding and momentum charges in two compact directions, but globally carries no net winding or momentum charge. We investigate its backreaction in the D1-D5 duality frame, where this object becomes a supertube which locally carries oscillating dipole D1-D5 and NS1-NS5 charges, and again carries no net charge. In the limit of an infinite straight supertube, we find an exact supergravity solution describing this object. We conjecture that a similar construction may be carried out based on a class of two-charge non-supersymmetric D1-D5 solutions. These results are a step towards demonstrating how neutral black hole microstates may ...
Oscillating supertubes and neutral rotating black hole microstates
Mathur, Samir D.; Turton, David
2014-04-01
The construction of neutral black hole microstates is an important problem, with implications for the information paradox. In this paper we conjecture a construction of non-supersymmetric supergravity solutions describing D-brane configurations which carry mass and angular momentum, but no other conserved charges. We first study a classical string solution which locally carries dipole winding and momentum charges in two compact directions, but globally carries no net winding or momentum charge. We investigate its backreaction in the D1-D5 duality frame, where this object becomes a supertube which locally carries oscillating dipole D1-D5 and NS1-NS5 charges, and again carries no net charge. In the limit of an infinite straight supertube, we find an exact supergravity solution describing this object. We conjecture that a similar construction may be carried out based on a class of two-charge non-supersymmetric D1-D5 solutions. These results are a step towards demonstrating how neutral black hole microstates may be constructed in string theory.
Mass loss from advective accretion disc around rotating black holes
Aktar, Ramiz; Nandi, Anuj
2015-01-01
We examine the properties of the outflowing matter from an advective accretion disc around a spinning black hole. During accretion, rotating matter experiences centrifugal pressure supported shock transition that effectively produces a virtual barrier around the black hole in the form of post-shock corona (hereafter, PSC). Due to shock compression, PSC becomes hot and dense that eventually deflects a part of the inflowing matter as bipolar outflows because of the presence of extra thermal gradient force. In our approach, we study the outflow properties in terms of the inflow parameters, namely specific energy (${\\mathcal E}$) and specific angular momentum ($\\lambda$) considering the realistic outflow geometry around the rotating black holes. We find that spin of the black hole ($a_k$) plays an important role in deciding the outflow rate $R_{\\dot m}$ (ratio of mass flux of outflow and inflow), in particular, $R_{\\dot m}$ is directly correlated with $a_k$ for the same set of inflow parameters. It is found that ...
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...
Geometro-thermodynamics of tidal charged black holes
International Nuclear Information System (INIS)
Tidal charged spherically symmetric vacuum brane black holes are characterized by their mass m and tidal charge q, an imprint of the five-dimensional Weyl curvature. For q>0 they are formally identical to the Reissner-Nordstroem black hole of general relativity. We study the thermodynamics and thermodynamic geometries of tidal charged black holes and discuss similarities and differences as compared to the Reissner-Nordstroe m black hole. As a similarity, we show that (for q>0) the heat capacity of the tidal charged black hole diverges on a set of measure zero of the parameter space, nevertheless both the regularity of the Ruppeiner metric and a Poincare stability analysis show no phase transition at those points. The thermodynamic state spaces being different indicates that the underlying statistical models could be different. We find that the q<0 parameter range, which enhances the localization of gravity on the brane, is thermodynamically preferred. Finally we constrain for the first time the possible range of the tidal charge from the thermodynamic limit on gravitational radiation efficiency at black hole mergers. (orig.)
Thermal Fluctuations in a Charged AdS Black Hole
Pourhassan, B
2015-01-01
In this paper, we will analyze the effects of thermal fluctuations on a charged AdS black hole. This will be done by analyzing the corrections to black hole thermodynamics due to these thermal fluctuations. We will demonstrate that the entropy of this black hole get corrected by logarithmic term. We will also calculate other corrections to other important thermodynamic quantities for this black hole. Finally, we will use the corrected value of the specific heat to analyze the phase transition in this system.
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.
Black holes, wormholes, and the disappearance of global charge
Coleman, Sidney Richard; Coleman, Sidney; Hughes, Shane
1993-01-01
One of the paradoxes associated with the theory of the formation and subsequent Hawking evaporation of a black hole is the disappearance of conserved global charges. It has long been known that metric fluctuations at short distances (wormholes) violate global-charge conservation; if global charges are apparently conserved at ordinary energies, it is only because wormhole-induced global-charge-violating terms in the low-energy effective Lagrangian are suppressed by large mass denominators. However, such suppressed interactions can become important at the high energy densities inside a collapsing star. We analyze this effect for a simple model of the black-hole singularity. (Our analysis is totally independent of any detailed theory of wormhole dynamics; in particular it does not depend on the wormhole theory of the vanishing of the cosmological constant.) We find that in general all charge is extinguished before the infalling matter crosses the singularity. No global charge appears in the outgoing Hawking radi...
The adiabatic motion of charged dust grains in rotating magnetospheres
Northrop, T. G.; Hill, J. R.
1983-01-01
Adiabatic equations of motion are derived for the micrometer-sized dust grains detected in the Jovian and Saturn magnetospheres by the Pioneer 10 and 11 spacecraft. The adiabatic theory of charged particle motion is extended to the case of variable grain charge. Attention is focused on the innermost and outermost limits to the grain orbit evolution, with all orbits tending to become circular with time. The parameters such as the center equation of motion, the drift velocity, and the parallel equation of motion are obtained for grains in a rotating magnetosphere. Consideration is given to the effects of periodic grain charge-discharge, which are affected by the ambient plasma properties and the grain plasma velocity. The charge-discharge process at the gyrofrequency is determined to eliminate the invariance of the magnetic moment and cause the grain to exhibit radial movement. The magnetic moment increases or decreases as a function of the gyrophase of the charge variation.
Microscopic entropy of the three-dimensional rotating black hole of BHT massive gravity
Giribet, Gaston; Tempo, David; Troncoso, Ricardo
2009-01-01
Asymptotically AdS rotating black holes for the Bergshoeff-Hohm-Townsend (BHT) massive gravity theory in three dimensions are considered. In the special case when the theory admits a unique maximally symmetric solution, apart from the mass and the angular momentum, the black hole is described by an independent "gravitational hair" parameter, which provides a negative lower bound for the mass. This bound is saturated at the extremal case and, since the temperature and the semiclassical entropy vanish, it is naturally regarded as the ground state. The absence of a global charge associated with the gravitational hair parameter reflects through the first law of thermodynamics in the fact that the variation of this parameter can be consistently reabsorbed by a shift of the global charges, giving further support to consider the extremal case as the ground state. The rotating black hole fits within relaxed asymptotic conditions as compared with the ones of Brown and Henneaux, such that they are invariant under the s...
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
International Nuclear Information System (INIS)
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.)
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.)
Dirac quasinormal modes of two-dimensional charged dilatonic black holes
International Nuclear Information System (INIS)
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.)
Direct Measurements of Black Hole Charge with Future Astrometrical Missions
Zakharov, A F; Ingrosso, G; Nucita, A A
2005-01-01
Recently, Zakharov et al. (2005) considered the possibility of evaluating the spin parameter and the inclination angle for Kerr black holes in nearby galactic centers by using future advanced astrometrical instruments. A similar approach which uses the characteristic properties of gravitational retro-lensing images can be followed to measure the charge of Reissner-Nordstrom black hole. Indeed, in spite of the fact that their formation might be problematic, charged black holes are objects of intensive investigations. From the theoretical point of view it is well-known that a black hole is described by only three parameters, namely, its mass M, angular momentum J and charge Q. Therefore, it would be important to have a method for measuring all these parameters, preferably by model independent way. In this paper, we propose a procedure to measure the black hole charge by using the size of the retro-lensing images that can be revealed by future astrometrical missions. A discussion of the Kerr-Newmann black hole c...
Entropy of non-extreme rotating black holes in string theories
International Nuclear Information System (INIS)
We formulate the Rindler space description of rotating black holes in string theories. We argue that the comoving frame is the natural frame for studying the thermodynamics of rotating black holes and the statistical analysis of rotating black holes gets simplified in this frame. We also calculate statistical entropies of a general class of rotating black holes in heterotic strings on tori by applying the D-brane description and the correspondence principle. We find at least a qualitative agreement between the Bekenstein-Hawking entropies and the statistical entropies of these black hole solutions. (orig.)
Three-fluid-sourced, massive, two-charged, rotating as well as static wormholes
Azreg-Aïnou, Mustapha
2016-01-01
Lack of a consistent metric for generating rotating wormholes motivates us to present a new one endowed with interesting physical and geometrical properties. When combined with the generalized method of superposition of fields, which consists in attaching a form of matter to each moving frame, it generates massive and charged (charge without charge) two-fluid-sourced, massive and two-charged three-fluid-sourced, rotating as well as new static wormholes which, otherwise, can hardly be derived by integration. If the lapse function of the static wormhole is bounded from above, no closed timelike curves occur in the rotating counterpart. For positive energy densities dying out faster than $1/r$, the angular velocity includes in its expansion a correction term, to the leading one that corresponds to ordinary stars, proportional to $\\ln r/r^4$. Such a term is not present in the corresponding expansion for the Kerr-Newman black hole. Based on this observation and our previous work, the dragging effects of falling ne...
Berkooz, Micha; Zait, Amir
2012-01-01
In this work we discuss charged rotating black holes in $AdS_5 \\times S^5$ that degenerate to extremal black holes with zero entropy. These black holes have scaling properties between charge and angular momentum similar to those of Fermi surface operators in a subsector of $\\mathcal{N}=4$ SYM. We add a massless uncharged scalar to the five dimensional supergravity theory, such that it still forms a consistent truncation of the type IIB ten dimensional supergravity and analyze its quasinormal modes. Separating the equation of motion to a radial and angular part, we proceed to solve the radial equation using the asymptotic matching expansion method applied to a Heun equation with two nearby singularities. We use the continued fraction method for the radial part and obtain numerical results for the quasinormal modes. In the case of the supersymmetric black hole we present some analytic results for the decay rates of the scalar perturbations. The spectrum of quasinormal modes obtained is similar to that of a chir...
Radiation of charged black holes and modified dispersion relation
Kamali, A. D.; Pedram, P.
2016-05-01
We investigate the effects of a modified dispersion relation proposed by Majhi and Vagenas on the Reissner-Nordström black hole thermodynamics in a universe with large extra dimensions. It is shown that entropy, temperature and heat capacity receive new corrections and charged black holes in this framework have less degrees of freedom and decay faster compared to black holes in the Hawking picture. We also study the emission rate of black hole and compare our results with other quantum gravity approaches. In this regard, the existence of the logarithmic prefactor and the relation between dimensions and charge are discussed. This procedure is not only valid for a single horizon spacetime but it is also valid for the spacetimes with inner and outer horizons.
Radiation of Charged Black Holes and Modified Dispersion Relation
Kamali, A D
2016-01-01
We investigate the effects of a modified dispersion relation proposed by Majhi and Vagenas on the Reissner-Nordstr\\"{o}m black hole thermodynamics in a universe with large extra dimensions. It is shown that entropy, temperature and heat capacity receive new corrections and charged black holes in this framework have less degrees of freedom and decay faster compared to black holes in the Hawking picture. We also study the emission rate of black hole and compare our results with other quantum gravity approaches. In this regard, the existence of the logarithmic prefactor and the relation between dimensions and charge are discussed. This procedure is not only valid for a single horizon spacetime but it is also valid for the spacetimes with inner and outer horizons.
Quantum Gravity Effects On Charged Micro Black Holes Thermodynamics
Abbasvandi, N.; Soleimani, M. J.; 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...
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.
Charged black strings in a five-dimensional Kasner universe
Ishihara, Hideki; Kimura, Masashi; Matsuno, Ken
2015-01-01
We construct time-dependent charged black string solutions in five-dimensional Einstein-Maxwell theory. In the far region, the spacetime approaches a five-dimensional Kasner universe with a expanding three-dimensional space and a shrinking extra dimension. Near the event horizon, the spacetime is approximately static and has a smooth event horizon. We also study the motion of test particles around the black string and show the existence of quasi-circular orbits. Finally, we briefly discuss th...
Quasinormal modes of semiclassical electrically charged black holes
International Nuclear Information System (INIS)
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.
Accretion of radiation and rotating primordial black holes
Mahapatra, S.; Nayak, B.
2016-02-01
We consider rotating primordial black holes (PBHs) and study the effect of accretion of radiation in the radiation-dominated era. The central part of our analysis deals with the role of the angular momentum parameter on the evolution of PBHs. We find that both the accretion and evaporation rates decrease with an increase in the angular momentum parameter, but the rate of evaporation decreases more rapidly than the rate of accretion. This shows that the evaporation time of PBHs is prolonged with an increase in the angular momentum parameter. We also note that the lifetime of rotating PBHs increases with an increase in the accretion efficiency of radiation as in the case of nonrotating PBHs.
Quasars a supermassive rotating toroidal black hole interpretation
Spivey, R J
2000-01-01
A supermassive rotating toroidal black hole (TBH) is proposed as the fundamental structure of quasars and other jet-producing active galactic nuclei. Rotating protogalaxies gather matter from the central gaseous region leading to the birth of massive toroidal stars whose internal nuclear reactions proceed very rapidly. Once the nuclear fuel is spent, gravitational collapse produces a slender ring-shaped TBH remnant. These events are typically the first supernovae of the host galaxies. Given time the TBH mass increases through continued accretion by several orders of magnitude, the event horizon swells whilst the central aperture shrinks. The difference in angular velocities between the accreting matter and the TBH induces a magnetic field that is strongest in the region of the central aperture and innermost ergoregion. Due to the presence of negative energy states when such a gravitational vortex is immersed in an electromagnetic field, circumstances are near ideal for energy extraction via non-thermal radiat...
Slowly rotating black hole solutions in Horndeski gravity
Maselli, Andrea; Minamitsuji, Masato; Berti, Emanuele
2015-01-01
We study black hole solutions at first order in the Hartle-Thorne slow-rotation approximation in Horndeski gravity theories. We derive the equations of motion including also cases where the scalar depends linearly on time. In the Hartle-Thorne formalism, all first-order rotational corrections are described by a single frame-dragging function. We show that the frame dragging function is exactly the same as in general relativity for all known BH solutions in shift-symmetric Horndeski theories, with the exception of theories with a linear coupling to the Gauss-Bonnet invariant. Our results extend previous no-hair theorems for a broad class of Horndeski gravity theories.
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...
Akcay, Ali Riza
1999-01-01
This paper describes that the superconducting cosmic strings can be connected to an electrically charged black hole, and can be considerd as the hair of black hole. What the no-hair theorems show is that a large amount of information is lost when a body collapses to form a black hole. In addition, the no-hair theorem has not been proved for the Yang-Mills field. This paper proves and claims that the superconducting cosmic strings can be connected to an electrically charged hole when the curre...
Timelike geodesics around a charged spherically symmetric dilaton black hole
Directory of Open Access Journals (Sweden)
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.
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.
The gravitational effect on induced charge density for an obliquely rotating neutron star
International Nuclear Information System (INIS)
The effect om the induced charge density of the gravitational field of a rotating neutron star with its magnetic axis inclined with respect to the rotational axis is investigated. While gravitation increases the charge density the obliquity reduces it
The gravitational effect on induced charge density for an obliquely rotating neutron star
Energy Technology Data Exchange (ETDEWEB)
De Paolis, F. [Delaware Univ., Newark (United States). Bartol Research Inst.; Istituto Nazionale di Fisica Nucleare, Lecce (Italy); Qadir, A. [Quaid-i-Azam Univ., Islamabad (Pakistan). Dept. of Mathematics; Tarman, I.H. [King Fahd University of Petroleum and Minerals, Dharan (Saudi Arabia). Dept. of Mathematical Sciences
1999-11-01
The effect om the induced charge density of the gravitational field of a rotating neutron star with its magnetic axis inclined with respect to the rotational axis is investigated. While gravitation increases the charge density the obliquity reduces it.
Adiabatic motion of charged dust grains in rotating magnetospheres
International Nuclear Information System (INIS)
Dust grains in the ring systems and rapidly rotating magnetospheres of the outer planets such as Jupiter and Saturn may be sufficiently charged that the magnetic and electric forces on them are comparable with the gravitational force. The adiabatic theory of charged particle motion has previously been applied to electrons and atomic size particles. But it is also applicable to these charged dust grains in the micrometer and smaller size range. We derive here the guiding center equation of motion, drift velocity, and parallel equation of motion for these grains in a rotating magnetosphere. The effects of periodic grain charge-discharge have not been treated previously and have been included in this analysis. Grain charge is affected by the surrounding plasma properties and by the grain plasma velocity (among other factors), both of which may vary over the gyrocircle. The resulting charge-discharge process at the gyrofrequency destroys the invariance of the magnetic moment and causes a grain to move radially. The magnetic moment may increase or decrease, depending on the gyrophase of the charge variation. If it decreases, the motion is always toward synchronous radius for an equatorial grain. But the orbit becomes circular before the grain reaches synchronous radius, a conclusion that follows from an exact constant of the motion. This circularization can be viewed as a consequence of the gradual reduction in the magnetic moment. This circularization also suggests that dust grains leaving Io could not reach the region of the Jovian ring, but several effects could change that conclusion. Excellent qualitative and quantitative agreement is obtained between adiabatic theory and detailed numerical orbit integrations
Pair Production In Near Extremal Charged Black Holes
Chen, Chiang-Mei; Tang, Fu-Yi
2015-01-01
We study the spontaneous pair production, including the Schwinger mechanism and the Hawking radiation, of charged scalar and spinor particles from the near horizon region of (near) extremal charged black holes in the probe field limit. The pair production rate and the absorption cross section, as well as the retarded Green's functions of the probe fields are analytically computed. Moreover, the holographic description dual to the pair production is discussed.
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.
Collapse of differentially rotating supermassive stars: Post black hole formation
International Nuclear Information System (INIS)
We investigate the collapse of differentially rotating supermassive stars (SMSs) by means of 3+1 hydrodynamic simulations in general relativity. We particularly focus on the onset of collapse to understand the final outcome of collapsing SMSs. We find that the estimated ratio of the mass between the black hole and the surrounding disk from the equilibrium star is roughly the same as the results from numerical simulation. This suggests that the picture of axisymmetric collapse is adequate, in the absence of nonaxisymmetric instabilities, to illustrate the final state of the collapse. We also find that quasiperiodic gravitational waves continue to be emitted after the quasinormal mode frequency has decayed. We furthermore have found that when the newly formed black hole is almost extreme Kerr, the amplitude of the quasiperiodic oscillation is enhanced during the late stages of the evolution. Geometrical features, shock waves, and instabilities of the fluid are suggested as a cause of this amplification behavior. This alternative scenario for the collapse of differentially rotating SMSs might be observable by the Laser Interferometer Space Antenna.
Photonic Bell states creation around rotating black holes
Racorean, Ovidiu
2016-01-01
We argue that spinning black holes are capable to implement complex quantum information processes encoded in X-ray photons emitted by the accretion disk. Recently, numerical simulations showed that X-ray photons emitted by accretion disk acquire rotation of polarization angle and orbital angular momentum due to strong gravitational field in the vicinity of the rotating black holes. Based on these two degrees of freedom we construct a bipartite two-level quantum system of the photons emitted by the accretion disk. To characterize the quantum states of this system we consider linear entropy for the reduced density matrix of polarization with the intention to exploit its direct relation with the photons degree of polarization. Since the X-ray radiation has a minimum degree of polarization located at the transition region of the accretion disk, the linear entropy is higher for the photons emitted on this region inferring a higher degree of entanglement for the composite system. We emphasize that for an extreme ro...
Nonlinear electrodynamics and thermodynamic geometry of rotating dilaton black branes
Sheykhi, A.; Naeimipour, F.; Zebarjad, S. M.
2016-07-01
We construct a new class of rotating dilaton solutions in the presence of logarithmic nonlinear electrodynamics. These solutions represent black branes with flat horizon and contain k=[(n-1)/2] rotation parameters in n-dimensional spacetime where [ x] is the integer part of x. We study the causal structure of the spacetime and calculate thermodynamic and conserved quantities and show that these quantities satisfy the first law of thermodynamics on the black brane horizon, { dM}={ TdS}+{{{sum _{i=1}k}}}Ω id{J}i+{ Ud}{Q}. Then, we study geometrical approach towards thermodynamics by choosing an appropriate geometrical metric. We show that the singularity of the Ricci scalar coincides exactly with the phase transition points. We observe that our system encounters two types of phase transitions depending on the metric parameters. For the first one the heat capacity is zero and for the second one the heat capacity diverges. In the first kind of phase transition, the brane has a transition from an unstable non-physical to a stable physical state. In the second type of phase transition the brane moves from a stable to an unstable state. Finally, we comment on the dynamical stability of the obtained solutions under perturbations in four dimensions.
On Invariant Structures of Black Hole Charges
Ferrara, Sergio(Physics Department, Theory Unit, CERN, Geneva 23, CH, 1211, Switzerland); Marrani, Alessio; Yeranyan, Armen
2011-01-01
We study "minimal degree" complete bases of duality- and "horizontal"- invariant homogeneous polynomials in the flux representation of two-centered black hole solutions in two classes of D=4 Einstein supergravity models with symmetric vector multiplets' scalar manifolds. Both classes exhibit an SL(2,R) "horizontal" symmetry. The first class encompasses N=2 and N=4 matter-coupled theories, with semi-simple U-duality given by SL(2,R) x SO(m,n); the analysis is carried out in the so-called Calab...
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.
Rotating Black Holes in Metric-Affine Gravity
Baekler, P; Baekler, Peter; Hehl, Friedrich W.
2006-01-01
Within the framework of metric-affine gravity (MAG, metric and an independent linear connection constitute spacetime), we find, for a specific gravitational Lagrangian and by using {\\it prolongation} techniques, a stationary axially symmetric exact solution of the vacuum field equations. This black hole solution embodies a Kerr-deSitter metric and the post-Riemannian structures of torsion and nonmetricity. The solution is characterized by mass, angular momentum, and shear charge, the latter of which is a measure for violating Lorentz invariance.
Rotating black holes in an expanding universe from fake supergravity
Chimento, Samuele
2014-01-01
Using the recipe of arXiv:0902.4814, where all fake supersymmetric backgrounds of matter-coupled fake N=2, d=4 gauged supergravity were classified, we construct dynamical rotating black holes in an expanding FLRW universe. This is done for two different prepotentials that are both truncations of the stu model and correspond to just one vector multiplet. In this scenario, the cosmic expansion is driven by two U(1) gauge fields and by a complex scalar that rolls down its potential. Generically, the solutions of arXiv:0902.4814 are fibrations over a Gauduchon-Tod base space, and we make three different choices for this base, namely flat space, the three-sphere and the Berger sphere. In the first two cases, the black holes are determined by harmonic functions on the base, while in the last case they obey a deformed Laplace equation that contains the squashing parameter of the Berger sphere. This is the generalization to a cosmological context of the usual recipe in ungauged supergravity, where black holes are giv...
Buoyancy and Penrose Process Produce Jets from Rotating Black Holes
Semenov, V S; Heyn, M F
2014-01-01
The exact mechanism by which astrophysical jets are formed is still unknown. It is believed that necessary elements are a rotating (Kerr) black hole and a magnetised accreting plasma. We model the accreting plasma as a collection of magnetic flux tubes/strings. If such a tube falls into a Kerr black hole, then the leading portion loses angular momentum and energy as the string brakes, and to compensate for this loss, momentum and energy is redistributed to the trailing portion of the tube.} {We found that buoyancy creates a pronounced helical magnetic field structure aligned with the spin axis. Along the field lines, the plasma is centrifugally accelerated close to the speed of light. This process leads to unlimited stretching of the flux tube since one part of the tube continues to fall into the black hole and simultaneously the other part of the string is pushed outward. Eventually, reconnection cuts the tube, the inner part is filled with new material and the outer part forms a collimated bubble-structured...
Hawking Radiation of a Charged Black Hole in Quantum Gravity
Oda, Ichiro
2015-01-01
We study black hole radiation of a Reissner-Nordstrom black hole with an electric charge in the framework of quantum gravity. Based on a canonical quantization for a spherically symmetric geometry, under physically plausible assumptions, we solve the Wheeler-De Witt equation in the regions not only between the outer apparent horizon and the spatial infinity but also between the spacetime singularity and the inner apparent horizon, and then show that the mass loss rate of an evaporating black hole due to thermal radiation agrees with the semiclassical result when we choose an integration constant properly by physical reasoning. Furthermore, we also solve the Wheeler-De Witt equation in the region between the inner Cauchy horizon and the outer apparent horizon, and show that the mass loss rate of an evaporating black hole has the same expression. The present study is the natural generalization of the case of a Schwarzschild black hole to that of a charged Reissner-Nordstrom black hole.
Thermodynamics of topological nonlinear charged Lifshitz black holes
Zangeneh, M Kord; Dehghani, M H
2015-01-01
In this paper, we construct a new class of analytic topological Lifshitz black holes with constant curvature horizon in the presence of power-law Maxwell field in four and higher dimensions. We find that in order to obtain these exact Lifshitz solutions, we need a dilaton and at least three electromagnetic fields. Interestingly enough, we find that the reality of the charge of the electromagnetic field which is needed for having solutions with curved horizon rules out black holes with hyperbolic horizon. Next, we study the thermodynamics of these nonlinear charged Lifshitz black holes with spherical and flat horizons by calculating all the conserved and thermodynamic quantities of the solutions. Furthermore, we obtain a generalized Smarr formula and show that the first law of thermodynamics is satisfied. Finally, we perform a stability analysis in both canonical and grand-canonical ensembles. We find that the solutions are thermally stable in a proper ranges of the metric parameters.
Chaotic cold accretion on to black holes in rotating atmospheres
Gaspari, M; Oh, S Peng; Brighenti, F; Temi, P
2014-01-01
Using 3D high-resolution hydrodynamic simulations, we probe the impact of rotation on the hot and cold black hole accretion flow in a typical massive galaxy. In the adiabatic hot mode, the pressure-dominated flow forms a geometrically thick rotational barrier, suppressing the accretion rate to 1/3 of the spherical case value. Stirring the hot flow with subsonic turbulence results in similar suppression. When radiative cooling is dominant, the gas loses pressure support and circularizes in a cold thin disk. The accretion rate is low and decoupled from the cooling rate, albeit its level is higher than in the hot mode. In the more common state of a turbulent and heated atmosphere, chaotic cold accretion drives the dynamics as long as the gas velocity dispersion exceeds the rotational velocity, i.e. turbulent Taylor number Ta_t 1, the turbulent broadening, the efficiency of collisions, and the thermal instability growth weaken, damping the accretion rate by a factor Ta_t, until the cold disk dominates the dynami...
Strong gravitational lensing in a rotating Kaluza-Klein black hole with squashed horizons
International Nuclear Information System (INIS)
We have investigated the strong gravitational lensing in a rotating squashed Kaluza-Klein (KK) black hole spacetime. Our result show that the strong gravitational lensings in the rotating squashed KK black hole spacetime have some distinct behaviors from those in the backgrounds of the four-dimensional Kerr black hole and of the squashed KK Gödel black hole. In the rotating squashed KK black hole spacetime, the marginally circular photon radius ρps , the coefficient a-bar, b-bar, the deflection angle α(θ) in the ϕ direction and the corresponding observational variables are independent of whether the photon goes with or against the rotation of the background, which is different with those in the usual four-dimensional Kerr black hole spacetime. Moreover, we also find that with the increase of the scale of extra dimension ρ0, the marginally circular photon radius ρps and the angular position of the relativistic images θ∞ first decreases and then increases in the rotating squashed KK black hole for fixed rotation parameter b, but in the squashed KK Gödel black hole they increase for the smaller global rotation parameter j and decrease for the larger one. In the extremely squashed case ρ0=0, the coefficient a-bar in the rotating squashed KK black hole increases monotonously with the rotation parameter, but in the squashed KK Gödel black hole it is a constant and independent of the global rotation of the Gödel Universe. These information could help us to understand further the effects of the rotation parameter and the scale of extra dimension on the strong gravitational lensing in the black hole spacetimes
On Invariant Structures of Black Hole Charges
Ferrara, Sergio; Yeranyan, Armen
2012-01-01
We study "minimal degree" complete bases of duality- and "horizontal"- invariant homogeneous polynomials in the flux representation of two-centered black hole solutions in two classes of D=4 Einstein supergravity models with symmetric vector multiplets' scalar manifolds. Both classes exhibit an SL(2,R) "horizontal" symmetry. The first class encompasses N=2 and N=4 matter-coupled theories, with semi-simple U-duality given by SL(2,R) x SO(m,n); the analysis is carried out in the so-called Calabi-Vesentini symplectic frame (exhibiting maximal manifest covariance) and until order six in the fluxes included. The second class, exhibiting a non-trivial "horizontal" stabilizer SO(2), includes N=2 minimally coupled and N=3 matter coupled theories, with U-duality given by the pseudo-unitary group U(r,s) (related to complex flux representations). Finally, we comment on the formulation of special Kaehler geometry in terms of "generalized" groups of type E7.
Scalar clouds in charged stringy black hole-mirror system
International Nuclear Information System (INIS)
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 = mΩH, where m is the azimuthal index and ΩH 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 = qΦH for a charged scalar field, where q is the charge of the scalar field, and ΦH 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 rm. It is shown that analytical results of the mirror location rm 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.)
Einstein-charged scalar field theory: black hole solutions and their stability
Ponglertsakul, Supakchai; Dolan, Sam; Winstanley, Elizabeth(Consortium for Fundamental Physics, School of Mathematics and Statistics, University of Sheffield, Hicks Building, Hounsfield Road, Sheffield, S3 7RH, United Kingdom)
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.
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.
A rotating black hole solution for shape dynamics
International Nuclear Information System (INIS)
Shape dynamics is a classical theory of gravity which agrees with general relativity in many important aspects, but which possesses different gauge symmetries and can present some fundamental global differences with respect to Einstein space–times. Here, we present a general procedure for (locally) mapping stationary, axisymmetric general relativity solutions onto their shape dynamic counterparts. We focus in particular on the rotating black hole solution for shape dynamics and show that many of the properties of the spherically symmetric solution are preserved in the extension to the axisymmetric case: it is also free of physical singularities, it does not form a space–time at the horizon, and it possesses an inversion symmetry about the horizon which leads to us to interpret the solution as a wormhole. (paper)
The missing asymptotic sector of rotating black-hole spectroscopy
International Nuclear Information System (INIS)
The rotation of a Kerr black hole splits its low-frequency spectrum in two, so it was so far unclear why the known highly-damped resonances show no splitting. We find the missing, split sector, with spin s quasinormal modes approaching the total reflection frequencies ω(n∈N)=−ΩΔJ−iκ(n−s), where Ω, κ and ΔJ are the horizon's angular velocity, surface gravity, and induced change in angular momentum. Surprisingly, the new sector is at least partly polar, and corresponds to reversible J transitions. Its fundamental branch converges quickly, possibly affecting gravitational wave signals. A simple interpretation of the Carter constant of motion is proposed
An analytical formula for the vacuum polarization of rotating black holes
Cvetic, Mirjam; Satz, Alejandro
2015-01-01
We give an analytical formula for the vacuum polarization of a massless minimally coupled scalar field at the horizon of a rotating black hole with subtracted geometry. This is the first example of an exact, analytical result for a four-dimensional rotating black hole.
Quasars: a supermassive rotating toroidal black hole interpretation
Spivey, R. J.
2000-08-01
A supermassive rotating toroidal black hole (TBH) is proposed as the fundamental structure of quasars and other jet-producing active galactic nuclei. Rotating protogalaxies gather matter from the central gaseous region leading to the birth of massive toroidal stars, the internal nuclear reactions of which proceed very rapidly. Once the nuclear fuel is spent, gravitational collapse produces a slender ring-shaped TBH remnant. Transitory electron and neutron degeneracy stabilized collapse phases, although possible, are unlikely owing to the large masses involved thus these events are typically the first supernovae of the host galaxies. Given time, the TBH mass increases through continued accretion by several orders of magnitude, the event horizon swells whilst the central aperture shrinks. The difference in angular velocities between the accreting matter and the TBH induces a magnetic field that is strongest in the region of the central aperture and innermost ergoregion. Owing to the presence of negative energy states when such a gravitational vortex is immersed in an electromagnetic field, circumstances are near ideal for energy extraction via non-thermal radiation including the Penrose process and superradiant scattering. This establishes a self-sustaining mechanism whereby the transport of angular momentum away from the quasar by relativistic bi-directional jets reinforces both the modulating magnetic field and the TBH/accretion disc angular velocity differential. Continued mass-capture by the TBH results in contraction of the central aperture until the TBH topology transitions to being spheroidal, extinguishing quasar behaviour. Similar mechanisms may be operating in microquasars, supernovae and sources of repeating gamma-ray bursts when neutron density or black hole tori arise. Long-term TBH stability seems to require either a negative cosmological constant, a non-stationary space-time resulting from the presence of accreting matter or the intervention of quantum
Black holes, wormholes, and the disappearance of global charge
Coleman, Sidney; Hughes, Shane
1993-07-01
One of the paradoxes associated with the theory of the formation and subsequent Hawking evaporation of a black hole is the disappearance of conserved global charges. It has long been known that metric fluctuations at short distances (wormholes) violate global-charge conservation; if global charges are apparently conserved at ordinary energies, it is only because wormhole-induced global-charge-violating terms in the low-energy effective Lagrangian are suppressed by large mass denominators. However, such suppressed interactions can become important at the high energy densities inside a collapsing star. We analyze this effect for a simple model of the black-hole singularity. (Our analysis is totally independent of any detailed theory of wormhole dynamics; in particular it does not depend on the wormhole theory of the vanishing of the cosmological constant.) We find that in general all charge is extinguished before the infalling matter crosses the singularity. No global charge appears in the outgoing Hawking radiation because it has all gone down the wormholes.
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.)
International Nuclear Information System (INIS)
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.)
Charged black strings in a five-dimensional Kasner universe
Ishihara, Hideki; Matsuno, Ken
2016-01-01
We construct time-dependent charged black string solutions in five-dimensional Einstein-Maxwell theory. In the far region, the spacetime approaches a five-dimensional Kasner universe with a expanding three-dimensional space and a shrinking extra dimension. Near the event horizon, the spacetime is approximately static and has a smooth event horizon. We also study the motion of test particles around the black string and show the existence of quasi-circular orbits. Finally, we briefly discuss the stability of this spacetime.
On charged black holes in anti-de Sitter space
Energy Technology Data Exchange (ETDEWEB)
Brecher, Dominic [Department of Physics and Astronomy, University of British Columbia, Vancouver, British Columbia V6T 1Z1 (Canada); He, Jianyang [Department of Physics and Astronomy, University of British Columbia, Vancouver, British Columbia V6T 1Z1 (Canada); Rozali, Moshe [Department of Physics and Astronomy, University of British Columbia, Vancouver, British Columbia V6T 1Z1 (Canada)
2005-04-01
We study the region inside the event horizon of charged black holes in five dimensional asymptotically anti-de Sitter space, using as a probe two-sided correlators which are dominated by spacelike geodesics penetrating the horizon. The spacetimes we investigate include the Reissner-Nordstroem black hole and perturbations thereof. The perturbed spacetimes can be found exactly, enabling us to perform a local scan of the region between the inner and outer horizons. Surprisingly, the two-sided correlators we calculate seem to be geometrically protected from the instability of the inner horizon.
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.
Hod, Shahar
2015-01-01
It is shown that rapidly-rotating Kerr black holes are characterized by the dimensionless ratio $\\tau_{\\text{gap}}/\\tau_{\\text{emission}}=O(1)$, where $\\tau_{\\text{gap}}$ is the average time gap between the emission of successive Hawking quanta and $\\tau_{\\text{emission}}$ is the characteristic timescale required for an individual Hawking quantum to be emitted from the black hole. This relation implies that the Hawking cascade from rapidly-rotating black holes has an almost continuous charact...
New solutions of exotic charged black holes and their stability
Farhangkhah, N
2016-01-01
We find a class of charged black hole solutions in third order Lovelock Gravity. To obtain this class of solutions, we are not confined to the usual assumption of maximal symmetry on the horizon and will consider the solution whose boundary is Einstein space with supplementary conditions on its Weyl tensor. The Weyl tensor of such exotic horizons exposes two charge-like parameter to the solution. These parameters in addition with the electric charge, cause different features in compare with the charged solution with constant-curvature horizon. For this class of asymptotically flat and (A)dS solutions, the electric charge dominates the behavior of the metric as r goes to zero, and thus the central singularity is always timelike. We also compute the thermodynamic quantities for these solutions and will show that the first law of thermodynamics is satisfied. We also show that the extreme black holes with nonconstant-curvature horizons whose Ricci scalar are zero or a positive constant could exist depending on th...
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.
Entanglement Thermodynamics of the Generalized Charged BTZ Black Hole
Mansoori, Seyed Ali Hosseini; Darareh, Mahdi Davoudi; Janbaz, Sharooz
2015-01-01
In this paper, we investigate the entanglement entropy for the generalized charged BTZ black hole through the $AdS_{3}/CFT_{2}$ correspondence. Using the holographic description of the entanglement entropy for the strip-subsystem in boundary $CFT_{2}$, we will find the first law-like relation between the variation of holographic entanglement entropy and the variation of energy of the subsystem in terms of the mass and the electric charge up to the second order. We also obtain appropriate counterterms to renormalize the energy tensor associated with the bulk on-shell actions.
Entanglement thermodynamics of the generalized charged BTZ black hole
Mansoori, Seyed Ali Hosseini; Mirza, Behrouz; Darareh, Mahdi Davoudi; Janbaz, Shahrooz
2016-04-01
In this paper, we investigate the entanglement entropy for the generalized charged BTZ black hole through the AdS3/CFT2 correspondence. Using the holographic description of the entanglement entropy for the strip-subsystem in boundary CFT2, we will find the first law-like relation between the variation of holographic entanglement entropy and the variation of energy of the subsystem in terms of the mass and the electric charge up to the second-order. We also obtain appropriate counterterms to renormalize the energy tensor associated with the bulk on-shell actions.
Numerical modelling of charged black holes with massive dilaton
International Nuclear Information System (INIS)
The static and spherically symmetric electrically charged black hole solutions in Einstein-Born-Infeld gravity with massive dilaton are investigated numerically. The Continuous Analog of Newton Method is used to solve originated nonlinear boundary-value problems. The corresponding linearized BVPs are solved numerically by means of the spline-collocation scheme of the fourth order. An important class of solutions are the extremal ones. We show that the extremal horizons satisfy some nonlinear system of an algebraic equation. Depending on the charge q and dilaton mass γ the black holes can have either one, two, or three horizons. This allows one to construct a Hermite polynomial of the third order, which real roots describe the number, the kind and the values of the horizons. (author)
General Relativistic Simulations of Jet Formation in a Rapidly Rotating Black Hole Magnetosphere
Koide, Shinji; Meier, David L; Shibata, Kazunari; Kudoh, Takahiro
1999-01-01
To investigate the formation mechanism of relativistic jets in active galactic nuclei and micro-quasars, we have developed a new general relativistic magnetohydrodynamic code in Kerr geometry. Here we report on the first numerical simulation of jet formation in a rapidly-rotating (a=0.95) Kerr black hole magnetosphere. We study cases in which the Keplerian accretion disk is both co-rotating and counter-rotating with respect to the black hole rotation. In the co-rotating disk case, our results...
Extremal rotating black holes in the near-horizon limit: Phase space and symmetry algebra
Directory of Open Access Journals (Sweden)
G. Compère
2015-10-01
Full Text Available We construct the NHEG phase space, the classical phase space of Near-Horizon Extremal Geometries with fixed angular momenta and entropy, and with the largest symmetry algebra. We focus on vacuum solutions to d dimensional Einstein gravity. Each element in the phase space is a geometry with SL(2,R×U(1d−3 isometries which has vanishing SL(2,R and constant U(1 charges. We construct an on-shell vanishing symplectic structure, which leads to an infinite set of symplectic symmetries. In four spacetime dimensions, the phase space is unique and the symmetry algebra consists of the familiar Virasoro algebra, while in d>4 dimensions the symmetry algebra, the NHEG algebra, contains infinitely many Virasoro subalgebras. The nontrivial central term of the algebra is proportional to the black hole entropy. The conserved charges are given by the Fourier decomposition of a Liouville-type stress-tensor which depends upon a single periodic function of d−3 angular variables associated with the U(1 isometries. This phase space and in particular its symmetries can serve as a basis for a semiclassical description of extremal rotating black hole microstates.
Cosmic Censorship of Rotating Anti-de Sitter Black Hole with a Probe
Gwak, Bogeun
2015-01-01
We test the validity of cosmic censorship in the rotating anti-de Sitter black hole through a particle absorption. For this purpose, we investigate whether the extremal black hole can be overspun by a particle. We construct the particle equations of motions to satisfy the laws of thermodynamics. With the particle absorption, the mass of the extremal black hole increases more than the angular momentum. Therefore, the outer horizon of the black hole still exists, and cosmic censorship is valid.
Does a black hole rotate in Chern-Simons modified gravity?
Konno, Kohkichi; Tanda, Satoshi
2007-01-01
Rotating black hole solutions in the (3+1)-dimensional Chern-Simons modified gravity theory are discussed by taking account of perturbation around the Schwarzschild solution. The zenith-angle dependence of a metric function related to the frame-dragging effect is determined from a constraint equation independently of a choice of the embedding coordinate. We find that at least within the framework of the first-order perturbation method, the black hole cannot rotate for finite black hole mass if the embedding coordinate is taken to be a timelike vector. However, the rotation can be permitted in the limit of $M/r \\to 0$ (where $M$ is the black hole mass and $r$ is the radius). For a spacelike vector, the rotation can also be permitted for any value of the black hole mass.
Charge trap memory based on few-layer black phosphorus
Feng, Qi; Yan, Faguang; Luo, Wengang; Wang, Kaiyou
2016-01-01
Atomically thin layered two-dimensional materials, including transition-metal dichalcogenide (TMDC) and black phosphorus (BP), have been receiving much attention, because of their promising physical properties and potential applications in flexible and transparent electronic devices. Here, for the first time we show nonvolatile charge-trap memory devices, based on field-effect transistors with large hysteresis, consisting of a few-layer black phosphorus channel and a three dimensional (3D) Al2O3/HfO2/Al2O3 charge-trap gate stack. An unprecedented memory window exceeding 12 V is observed, due to the extraordinary trapping ability of the high-k HfO2. The device shows a high endurance of over 120 cycles and a stable retention of ~30% charge loss after 10 years, even lower than the reported MoS2 flash memory. The high program/erase current ratio, large memory window, stable retention and high on/off current ratio, provide a promising route towards flexible and transparent memory devices utilising atomically thin two-dimensional materials. The combination of 2D materials with traditional high-k charge-trap gate stacks opens up an exciting field of nonvolatile memory devices.
Charge trap memory based on few-layer black phosphorus.
Feng, Qi; Yan, Faguang; Luo, Wengang; Wang, Kaiyou
2016-02-01
Atomically thin layered two-dimensional materials, including transition-metal dichalcogenide (TMDC) and black phosphorus (BP), have been receiving much attention, because of their promising physical properties and potential applications in flexible and transparent electronic devices. Here, for the first time we show nonvolatile charge-trap memory devices, based on field-effect transistors with large hysteresis, consisting of a few-layer black phosphorus channel and a three dimensional (3D) Al2O3/HfO2/Al2O3 charge-trap gate stack. An unprecedented memory window exceeding 12 V is observed, due to the extraordinary trapping ability of the high-k HfO2. The device shows a high endurance of over 120 cycles and a stable retention of ∼30% charge loss after 10 years, even lower than the reported MoS2 flash memory. The high program/erase current ratio, large memory window, stable retention and high on/off current ratio, provide a promising route towards flexible and transparent memory devices utilising atomically thin two-dimensional materials. The combination of 2D materials with traditional high-k charge-trap gate stacks opens up an exciting field of nonvolatile memory devices. PMID:26758336
Conserved charges of black holes in Weyl and Einstein-Gauss-Bonnet gravities
International Nuclear Information System (INIS)
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.)
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.)
Growth of black holes in the interior of rotating neutron stars
DEFF Research Database (Denmark)
Kouvaris, C.; Tinyakov, P.
2014-01-01
Mini-black holes made of dark matter that can potentially form in the interior of neutron stars always have been thought to grow by accreting the matter of the core of the star via a spherical Bondi accretion. However, neutron stars have sometimes significant angular velocities that can...... in principle stall the spherical accretion and potentially change the conclusions derived about the time it takes for black holes to destroy a star. We study the effect of the star rotation on the growth of such black holes and the evolution of the black hole spin. Assuming no mechanisms of angular momentum...... evacuation, we find that even moderate rotation rates can in fact destroy spherical accretion at the early stages of the black hole growth. However, we demonstrate that the viscosity of nuclear matter can alleviate the effect of rotation, making it possible for the black hole to maintain spherical accretion...
Liu, Hang
2016-01-01
In this paper, we investigate the angular momentum independence of the entropy sum and product for AdS rotating black holes based on the first law of thermodynamics and a mathematical lemma related to Vandermonde determinant. The advantage of this method is that the explicit forms of the spacetime metric, black hole mass and charge are not needed but the Hawking temperature and entropy formula on the horizons are necessary for static black holes, while our calculations require the expressions of metric and angular velocity formula. We find that the entropy sum is always independent of angular momentum for all dimensions and the angular momentum-independence of entropy product only holds for the dimensions $d>4$ with at least one rotation parameter $a_i=0$, while the mass-free of entropy sum and entropy product for rotating black holes only stand for higher dimensions ($d>4$) and for all dimensions, respectively. On the other hand, we find that the introduction of a negative cosmological constant does not affe...
Liu, Hang; Meng, Xin-he
2016-08-01
In this paper, we investigate the angular momentum independence of the entropy sum and product for AdS rotating black holes based on the first law of thermodynamics and a mathematical lemma related to Vandermonde determinant. The advantage of this method is that the explicit forms of the spacetime metric, black hole mass and charge are not needed but the Hawking temperature and entropy formula on the horizons are necessary for static black holes, while our calculations require the expressions of metric and angular velocity formula. We find that the entropy sum is always independent of angular momentum for all dimensions and the angular momentum-independence of entropy product only holds for the dimensions d > 4 with at least one rotation parameter ai = 0, while the mass-free of entropy sum and entropy product for rotating black holes only stand for higher dimensions (d > 4) and for all dimensions, respectively. On the other hand, we find that the introduction of a negative cosmological constant does not affect the angular momentum-free of entropy sum and product but the criterion for angular momentum-independence of entropy product will be affected.
Thermodynamics of a charged hairy black hole in (2+1) dimensions
Sadeghi, J.; H. Farahani
2013-01-01
In this paper we study thermodynamics, statistics and spectroscopic aspects of a charged black hole with a scalar hair coupled to the gravity in (2+1) dimensions. We obtained effects of the black hole charge and scalar field on the thermodynamical and statistical quantities. We find that scalar charge may increase entropy, temperature and probability, while may decrease black hole mass, free and internal energy. Also electric charge increases probability and decreases temperature and internal...
Energy Technology Data Exchange (ETDEWEB)
Hod, Shahar [The Ruppin Academic Center, Emek Hefer (Israel); The Hadassah Institute, Jerusalem (Israel)
2015-07-15
It is shown that rapidly-rotating Kerr black holes are characterized by the dimensionless ratio τ{sub gap}/τ{sub emission} = O(1), where τ{sub gap} is the average time gap between the emissions of successive Hawking quanta and τ{sub emission} is the characteristic timescale required for an individual Hawking quantum to be emitted from the black hole. This relation implies that the Hawking cascade from rapidly-rotating black holes has an almost continuous character. Our results correct some inaccurate claims that recently appeared in the literature regarding the nature of the Hawking black-hole evaporation process. (orig.)
Hod, Shahar
2015-01-01
It is shown that rapidly-rotating Kerr black holes are characterized by the dimensionless ratio $\\tau_{\\text{gap}}/\\tau_{\\text{emission}}=O(1)$, where $\\tau_{\\text{gap}}$ is the average time gap between the emission of successive Hawking quanta and $\\tau_{\\text{emission}}$ is the characteristic timescale required for an individual Hawking quantum to be emitted from the black hole. This relation implies that the Hawking cascade from rapidly-rotating black holes has an almost continuous character. Our results correct some inaccurate claims that recently appeared in the literature regarding the nature of the Hawking black-hole evaporation process.
International Nuclear Information System (INIS)
It is shown that rapidly-rotating Kerr black holes are characterized by the dimensionless ratio τgap/τemission = O(1), where τgap is the average time gap between the emissions of successive Hawking quanta and τemission is the characteristic timescale required for an individual Hawking quantum to be emitted from the black hole. This relation implies that the Hawking cascade from rapidly-rotating black holes has an almost continuous character. Our results correct some inaccurate claims that recently appeared in the literature regarding the nature of the Hawking black-hole evaporation process. (orig.)
Thermodynamics of three-dimensional black holes via charged particle absorption
Bogeun Gwak; Bum-Hoon Lee
2016-01-01
We have shown that changes occur in a (2+1)-dimensional charged black hole by adding a charged probe. The particle increases the entropy of the black hole and guarantees the second law of thermodynamics. The first law of thermodynamics is derived from the change in the black hole mass. Using the particle absorption, we test the extremal black hole and find out that the mass of the extremal black hole increases more than the electric charge. Therefore, the outer horizon of the black hole still...
Thermodynamics of three-dimensional black holes via charged particle absorption
Gwak, Bogeun; Lee, Bum-Hoon
2016-04-01
We have shown that changes occur in a (2 + 1)-dimensional charged black hole by adding a charged probe. The particle increases the entropy of the black hole and guarantees the second law of thermodynamics. The first law of thermodynamics is derived from the change in the black hole mass. Using the particle absorption, we test the extremal black hole and find out that the mass of the extremal black hole increases more than the electric charge. Therefore, the outer horizon of the black hole still exists. However, the extremal condition becomes non-extremal.
Thermodynamics of Three-dimensional Black Holes via Charged Particle Absorption
Gwak, Bogeun
2015-01-01
We have shown that changes occur in a (2+1)-dimensional charged black hole by adding a charged probe. The particle increases the entropy of the black hole and guarantees the second law of thermodynamics. The first law of thermodynamics is derived from the change in the black hole mass. Using the particle absorption, we test the extremal black hole and find out that the mass of the extremal black hole increases more than the electric charge. Therefore, the outer horizon of the black hole still exists. However, the extremal condition becomes non-extremal.
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...
Adding new hair to the 3-charge black ring
International Nuclear Information System (INIS)
Motivated by the string theory analysis of Giusto et al (2011 JHEP1111(2011)062), we construct a class of 1/8-BPS solutions of type-IIB supergravity compactified on S1 x T4. In this duality frame, our ansatz allows for a non-trivial NSxNS B-field, which has been usually set to zero in previous studies of 1/8-BPS geometries. We provide an M-theory description of these new geometries and show that they can be interpreted as the lift of solutions of the N=2 5D supergravity with three vector multiplets and whose scalar manifold is the symmetric space SO(1, 1)x(SO(1, 2)/SO(2)). Finally, we show that the non-minimal 5D black rings provide an explicit example of solutions falling in this ansatz. In particular, we point out the existence of a black ring that has an extra dipole charge with respect to the solutions of the STU model. In the near-horizon limit, this ring has an AdS3 x S3 geometry with the same radius as the one of the 3-charge black hole, and thus, its microstates should belong to the usual D1-D5 CFT. (paper)
Adding new hair to the 3-charge black ring
Giusto, Stefano
2012-01-01
Motivated by the string theory analysis of arXiv:1108.6331, we construct a class of 1/8-BPS solutions of type IIB supergravity compactified on S^1 x T^4. In this duality frame our ansatz allows for a non-trivial NS-NS B-field which has been usually set to zero in previous studies of 1/8-BPS geometries. We provide a M-theory description of these new geometries and show that they can be interpreted as the lift of solutions of the N=2 5D supergravity with three vector multiplets and whose scalar manifold is the symmetric space SO(1,1) x (SO(1,2)/SO(2)). Finally we show that the non-minimal 5D black rings provide an explicit example of solutions falling in this ansatz. In particular we point out the existence of a black ring that has an extra dipole charge with respect to the solutions of the STU-model. In the near-horizon limit, this ring has an AdS_3 x S^3 geometry with the same radius as the one of the 3-charge black hole and thus its microstates should belong to the usual D1-D5 CFT.
Thermodynamics of topological nonlinear charged Lifshitz black holes
Zangeneh, M. Kord; Sheykhi, A.; Dehghani, M. H.
2015-07-01
In this paper, we construct a new class of analytic topological Lifshitz black holes with constant curvature horizon in the presence of a power-law Maxwell field in four or more dimensions. We find that in order to obtain these exact Lifshitz solutions, we need a dilaton and at least three electromagnetic fields. Interestingly enough, we find that the reality of the charge of the electromagnetic field which is needed for having solutions with a curved horizon rules out black holes with a hyperbolic horizon. Next, we study the thermodynamics of these nonlinear charged Lifshitz black holes with spherical and flat horizons by calculating all of the conserved and thermodynamic quantities of the solutions. Furthermore, we obtain a generalized Smarr formula and show that the first law of thermodynamics is satisfied. We also perform a stability analysis in both canonical and grand-canonical ensembles. We find that the solutions are thermally stable in proper ranges of the metric parameters. Finally, we comment on the dynamical stability of the obtained solutions under perturbations in four dimensions.
Övgün, Ali; Jusufi, Kimet
2016-05-01
In this paper, we investigate the tunneling process of charged massive bosons W^{±} (spin-1 particles) from noncommutative charged black holes such as charged RN black holes and charged BTZ black holes. By applying the WKB approximation and by using the Hamilton-Jacobi equation we derive the tunneling rate and the corresponding Hawking temperature for those black holes configuration. Furthermore, we show the quantum gravity effects using the GUP on the Hawking temperature for the noncommutative RN black holes. The tunneling rate shows that the radiation deviates from pure thermality and is consistent with an underlying unitary theory.
Thermodynamic instability of nonlinearly charged black holes in gravity's rainbow
Hendi, S. H.; Panahiyan, S.; Panah, B. Eslam; Momennia, M.
2016-03-01
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.
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...
Non-commutative geometry inspired charged black holes
International Nuclear Information System (INIS)
We find a new, non-commutative geometry inspired, solution of the coupled Einstein-Maxwell field equations describing a variety of charged, self-gravitating objects, including extremal and non-extremal black holes. The metric smoothly interpolates between de Sitter geometry, at short distance, and Reissner-Nordstrom geometry far away from the origin. Contrary to the ordinary Reissner-Nordstrom spacetime there is no curvature singularity in the origin neither 'naked' nor shielded by horizons. We investigate both Hawking process and pair creation in this new scenario
Singularity deep inside the spherical charged black hole core
Burko, L M
1999-01-01
We study analytically the spacelike singularity inside a spherically-symmetric, charged black hole coupled to a self-gravitating spherical massless scalar field. We assume spatial homogeneity, and find a generic solution in terms of a formal series expansion. This solution is tested against fully-nonlinear and inhomogeneous numerical simulations. We find full compliance between our analytical solution and the pointwise behavior of the singularity in the numerical simulations. This is a strong scalar-curvature monotonic spacelike singularity, which connects to a weak null singularity at asymptotically-late advanced time.
Thin-shell wormholes from regular charged black holes
Rahaman, F; Rakib, Sk A; Kuhfittig, Peter K F
2009-01-01
We investigate a new thin-shell wormhole constructed by surgically grafting two regular charged black holes arising from the action using nonlinear electrodynamics coupled to general relativity. The stress-energy components within the shell violate the null and weak energy conditions but obey the strong energy condition. We study the stability in two ways: (i) taking a specific equation of state at the throat and (ii) analyzing the stability to linearized spherically symmetric perturbations about a static equilibrium solution. Various other aspects of this thin-shell wormhole are also analyzed.
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.
Another new form of the rotating squashed black hole solution and its thermodynamics
Zhu, Xiao-Dan; Wu, Di; Wu, Shuang-Qing; Yang, Shu-Zheng
2016-01-01
In a previous work, we had obtained a new simple form for the five-dimensional rotating squashed black hole solution by solving directly the vacuum Einstein field equations. In this paper, using a different metric ansatz, we have obtained another new but relatively simple form for the rotating uncharged black hole with squashed horizons. We then found its relation to our previous solution and investigated its thermodynamics by means of the counterterm method. Compared with the previous result...
Hawking radiation of spin-1 particles from a three-dimensional rotating hairy black hole
Energy Technology Data Exchange (ETDEWEB)
Sakalli, I.; Ovgun, A., E-mail: ali.ovgun@emu.edu.tr [Eastern Mediterranean University Famagusta, North Cyprus, Department of Physics (Turkey)
2015-09-15
We study the Hawking radiation of spin-1 particles (so-called vector particles) from a three-dimensional rotating black hole with scalar hair using a Hamilton–Jacobi ansatz. Using the Proca equation in the WKB approximation, we obtain the tunneling spectrum of vector particles. We recover the standard Hawking temperature corresponding to the emission of these particles from a rotating black hole with scalar hair.
Hawking radiation of spin-1 particles from a three-dimensional rotating hairy black hole
Sakalli, I.; Ovgun, A.
2015-09-01
We study the Hawking radiation of spin-1 particles (so-called vector particles) from a three-dimensional rotating black hole with scalar hair using a Hamilton-Jacobi ansatz. Using the Proca equation in the WKB approximation, we obtain the tunneling spectrum of vector particles. We recover the standard Hawking temperature corresponding to the emission of these particles from a rotating black hole with scalar hair.
Hawking radiation of spin-1 particles from a three-dimensional rotating hairy black hole
International Nuclear Information System (INIS)
We study the Hawking radiation of spin-1 particles (so-called vector particles) from a three-dimensional rotating black hole with scalar hair using a Hamilton–Jacobi ansatz. Using the Proca equation in the WKB approximation, we obtain the tunneling spectrum of vector particles. We recover the standard Hawking temperature corresponding to the emission of these particles from a rotating black hole with scalar hair
A new metric for rotating black holes in Gauss-Bonnet gravity
Institute of Scientific and Technical Information of China (English)
Yue Rui-Hong; Zou De-Cheng; Yu Tian-Yi; Yang Zhan-Ying
2011-01-01
This paper presents a new metric and studies slowly rotating Gauss-Bonnet black holes with a nonvanishing angular momentum in five dimensional anti-de Sitter spaces. Taking the angular momentum parameter a up to second order, the slowly rotating black hole solutions are obtained by working directly in the action. In addition, it also finds that this method is applicable in higher order Lovelock gravity.
Chaotic motion of particles in the accelerating and rotating black holes spacetime
Chen, Songbai; Wang, Mingzhi; Jing, Jiliang
2016-01-01
We have investigated the motion of timelike particles along geodesic in the background of accelerating and rotating black hole spacetime. We confirmed that the chaos exists in the geodesic motion of the particles by Poincar\\'e sections, the power spectrum, the fast Lyapunov exponent indicator and the bifurcation diagram. Moreover, we probe the effects of the acceleration and rotation parameters on the chaotic behavior of a timelike geodesic particle in the black hole spacetime. Our results sh...
A new metric for rotating black holes in Gauss—Bonnet gravity
International Nuclear Information System (INIS)
This paper presents a new metric and studies slowly rotating Gauss-Bonnet black holes with a nonvanishing angular momentum in five dimensional anti-de Sitter spaces. Taking the angular momentum parameter a up to second order, the slowly rotating black hole solutions are obtained by working directly in the action. In addition, it also finds that this method is applicable in higher order Lovelock gravity. (general)
A rotating black hole in the Galactic Center
Falcke, H; Duschl, W J; Mezger, P G; Falcke, Heino; Biermann, Peter L.; Duschl, Wolfgang J.; Mezger, Peter G.
1993-01-01
Recent observations of Sgr A* give strong constraints for possible models of the physical nature of Sgr A* and suggest the presence of a massive black~hole with M0.9) accreting 10^-8.5 - 10^-7 M_sun/yr at a black~hole mass of M=2 10^6 M_sunseen almost edge on. A low mass black hole of M<10^3 M_sun seems to be very unlikely. We provide a ``Hertzsprung-Russell diagram for black holes'' together with simple scaling laws to provide an easy-to-handle test for the black hole model.
Faraday rotation of plasmas in the vicinity of a Schwarzschild black hole
Asenjo, Felipe; Bhattacharjee, Chinmoy; Mahajan, Swadesh
2015-11-01
The propagation of an electromagnetic wave in a multi-specie plasmas (ion-electron and ion-electron-positron), embedded in the gravitational field of a Schwarzschild black hole, is investigated with particular emphasis on studying the Faraday rotation (rotation of the phase angle of the right and left-handed components of wave). In order to appropriately deal with the strong gravitational field (affecting the plasma in the proximity of the black hole horizon), we employ Rindler coordinates in the 3 +1 decomposition of general relativity. The rather complex dispersion relation for high-frequency electromagnetic waves reveals the dependence of Faraday rotation on the number density of different constituents of the multi-specie plasma, the background magnetic field, and the mass of the black hole. Amongst other things, the expression for the Faraday rotation allows us to determine the black hole mass if the number density and magnetic field strength are estimated, and the rotation of the phase angle is measured. It is also shown how Faraday rotation could be harnessed to infer black hole features in a more complete theory that pertains, for example, to Kerr black holes. Different astrophysical implications are pointed out. Felipe Asenjo thanks CONICyT for funding No. 79130002.
On a general class of regular rotating black holes based on a smeared mass distribution
Directory of Open Access Journals (Sweden)
Alexis Larranaga
2015-04-01
Full Text Available In this work we investigate the behavior of a new general class of rotating regular black holes based on a non-Gaussian smeared mass distribution. It is shown that the existence of a fundamental minimal length cures the well-known problems in the terminal phase of black hole evaporation, since we find that there is a finite maximum temperature that the black hole reaches before cooling down to absolute zero, so that the evaporation ends up in a zero temperature extremal black hole whose mass and size depends on the value of the fundamental length and on the rotation parameter of the black hole. We also study the geodesic structure in these spacetimes and calculate the shadows that these black holes produce.
Rahaman, Farook; Bhar, Piyali; Sharma, Ranjan; Tiwari, Rishi Kumar
2015-03-01
We report a -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.
Gravitational wave production by rotating primordial black holes
Dong, Ruifeng; Kinney, William H.; Stojkovic, Dejan
2015-01-01
In this paper we analyze in detail a rarely discussed question of gravity waves production from evaporating black holes. Evaporating black holes emit gravitons which are at classical level registered as gravity waves. We use the latest constraints on the primordial black hole abundance, and calculate the power emitted in gravitons at the time of their evaporation. We then solve the coupled system of equations that gives us the evolution of the frequency and amplitude of gravity waves during t...
Gravitational wave production by rotating primordial black holes
Dong, Ruifeng; Stojkovic, Dejan
2015-01-01
In this paper we analyze in detail a rarely discussed question of gravity waves production from evaporating black holes. Evaporating black holes emit gravitons which are at classical level registered as gravity waves. We use the latest constraints on the primordial black hole abundance, and calculate the power emitted in gravitons at the time of their evaporation. We then solve the coupled system of equations that gives us the evolution of the frequency and amplitude of gravity waves during the expansion of the universe. The spectrum of gravitational waves that can be detected today depends on multiple factors: fraction of the total energy density which was occupied by black holes, the epoch in which the black holes are formed, and quantities like mass and angular momentum of evaporating black holes. We conclude that very small primordial black holes which evaporate before the nucleosynthesis emit gravitons whose spectral energy fraction today can be as large as $10^{-5}$. On the other hand, primordial black ...
Inside charged black holes. II. Baryons plus dark matter
International Nuclear Information System (INIS)
This is the second of two companion papers on the interior structure of self-similar accreting charged black holes. In the first paper, the black hole was allowed to accrete only a single fluid of charged baryons. In this second paper, the black hole is allowed to accrete in addition a neutral fluid of almost noninteracting dark matter. Relativistic streaming between outgoing baryons and ingoing dark matter leads to mass inflation near the inner horizon. When enough dark matter has been accreted that the center-of-mass frame near the inner horizon is ingoing, then mass inflation ceases and the fluid collapses to a central singularity. A null singularity does not form on the Cauchy horizon. Although the simultaneous presence of ingoing and outgoing fluids near the inner horizon is essential to mass inflation, reducing one or the other of the ingoing dark matter or outgoing baryonic streams to a trace relative to the other stream makes mass inflation more extreme, not the other way around as one might naively have expected. Consequently, if the dark matter has a finite cross section for being absorbed into the baryonic fluid, then the reduction of the amount of ingoing dark matter merely makes inflation more extreme, the interior mass exponentiating more rapidly and to a larger value before mass inflation ceases. However, if the dark matter absorption cross section is effectively infinite at high collision energy, so that the ingoing dark matter stream disappears completely, then the outgoing baryonic fluid can drop through the Cauchy horizon. In all cases, as the baryons and the dark matter voyage to their diverse fates inside the black hole, they only ever see a finite amount of time pass by in the outside universe. Thus the solutions do not depend on what happens in the infinite past or future. We discuss in some detail the physical mechanism that drives mass inflation. Although the gravitational force is inward, inward means opposite direction for ingoing and
Energetics and optical properties of 6-dimensional rotating black hole in pure Gauss-Bonnet gravity
International Nuclear Information System (INIS)
We study physical processes around a rotating black hole in pure Gauss-Bonnet (GB) gravity. In pure GB gravity, the gravitational potential has a slower fall-off as compared to the corresponding Einstein potential in the same dimension. It is therefore expected that the energetics of a pure GB black hole would be weaker, and our analysis bears out that the efficiency of energy extraction by the Penroseprocess is increased to 25.8 % and the particle acceleration is increased to 55.28 %; the optical shadow of the black hole is decreased. These are in principle distinguishing observable features of a pure GB black hole. (orig.)
Energetics and optical properties of 6-dimensional rotating black hole in pure Gauss-Bonnet gravity
Energy Technology Data Exchange (ETDEWEB)
Abdujabbarov, Ahmadjon; Ahmedov, Bobomurat [Institute of Nuclear Physics, Tashkent (Uzbekistan); Ulugh Beg Astronomical Institute, Tashkent (Uzbekistan); Atamurotov, Farruh [Institute of Nuclear Physics, Tashkent (Uzbekistan); Inha University in Tashkent, Tashkent (Uzbekistan); Dadhich, Naresh [Inter-University Centre for Astronomy and Astrophysics, Post Bag 4, Pune (India); Jamia Millia Islamia, Centre for Theoretical Physics, New Delhi (India); Stuchlik, Zdenek [Silesian University in Opava, Institute of Physics, Faculty of Philosophy and Science, Opava (Czech Republic)
2015-08-15
We study physical processes around a rotating black hole in pure Gauss-Bonnet (GB) gravity. In pure GB gravity, the gravitational potential has a slower fall-off as compared to the corresponding Einstein potential in the same dimension. It is therefore expected that the energetics of a pure GB black hole would be weaker, and our analysis bears out that the efficiency of energy extraction by the Penroseprocess is increased to 25.8 % and the particle acceleration is increased to 55.28 %; the optical shadow of the black hole is decreased. These are in principle distinguishing observable features of a pure GB black hole. (orig.)
New class of rotating perfect fluid black holes in three dimensional gravity
Energy Technology Data Exchange (ETDEWEB)
Wu, Bin [Nankai University, School of Physics, Tianjin (China); Xu, Wei [Nankai University, School of Physics, Tianjin (China); Huazhong University of Science and Technology, School of Physics, Wuhan (China)
2014-08-15
We obtain a new class of rotating black holes for Einstein theory with perfect fluid source in (2 + 1) dimensions. We conclude that these black hole solutions only depend on the variable of the angular velocity m(r). Some examples of these black holes are given explicitly. In particular, an unknown static black hole in this special background is obtained. In addition, the general properties including the horizon structure, energy conditions and equation of state, mass, and angular momentum are explained in detail. (orig.)
New class of rotating perfect fluid black holes in three dimensional gravity
International Nuclear Information System (INIS)
We obtain a new class of rotating black holes for Einstein theory with perfect fluid source in (2 + 1) dimensions. We conclude that these black hole solutions only depend on the variable of the angular velocity m(r). Some examples of these black holes are given explicitly. In particular, an unknown static black hole in this special background is obtained. In addition, the general properties including the horizon structure, energy conditions and equation of state, mass, and angular momentum are explained in detail. (orig.)
Directory of Open Access Journals (Sweden)
Meng Sun
2015-08-01
Full Text Available We give a general illumination of a rotating black string falling into a rotating horizon in dimension D=5. It is a configuration of one smooth intersection between these two objects when the spacetime is axisymmetric and in the limit that the thickness of the black hole is much larger than the thickness of the black string. Following this configuration, we further extend them to the rotating and charged flows.
Synchrotron and Smith-Purcell radiations from a charge rotating around a cylindrical grating
Saharian, A A; Mkrtchyan, A R; Khachatryan, B V
2016-01-01
We investigate the radiation from a charge rotating around conductors with cylindrical symmetry. First the problem is considered with a charge rotating around a conducting cylinder immersed in a homogeneous medium. The surface charge and current densities induced on the cylinder surface are evaluated. A formula is derived for the spectral-angular density of the radiation intensity. In the second part, we study the radiation for a charge rotating around a diffraction grating on a cylindrical surface with metallic strips parallel to the cylinder axis. The effect of the grating on the radiation intensity is approximated by the surface currents induced on the strips by the field of the rotating charge. The expressions are derived for the electric and magnetic fields and for the angular density of the radiation intensity on a given harmonic. We show that the interference between the synchrotron and Smith-Purcell radiations may lead to interesting features. In particular, the behavior of the radiation intensity on ...
Capture and critical scattering of a long cosmic string by a rotating black hole
International Nuclear Information System (INIS)
The capture of a straight, infinitely long cosmic string by a rotating black hole with rotation parameter a is considered. We assume that a string is moving with velocity v and that initially the string is parallel to the axis of rotation of the black hole and has the impact parameter b. The string can be either scattered or captured by the black hole. We demonstrate that there exists a critical value of the impact parameter bc(v, a) which separates these two regimes. Using numerical simulations we obtain the critical impact parameter curve for different values of the rotation parameter a. We show that for the prograde motion of the string this curve lies below the curve for the retrograde motion. Moreover, for ultrarelativistic strings moving in the prograde direction and nearly extremal black holes the critical impact parameter curve is found to be a multiply valued function of v. We obtain real time profiles of the scattered strings in the regime close to the critical. We also study critical scattering and capture of strings by the rotating black hole in the relativistic and ultrarelativistic regimes and especially such relativistic effects as coil formation and wrapping effect
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–
Effect of brane thickness on microscopic tidal-charged black holes
International Nuclear Information System (INIS)
We study the phenomenological implications stemming from the dependence of the tidal charge on the brane thickness L for the evaporation and decay of microscopic black holes. In general, the larger L, the longer are the black hole lifetimes and the greater their maximum mass for those cases in which the black hole can grow. In particular, we again find that tidal-charged black holes might live long enough to escape the detectors and even the gravitational field of the Earth, thus resulting in large amounts of missing energy. However, under no circumstances could TeV-scale black holes grow enough to enter the regime of Bondi accretion.
Slowly rotating charged fluid balls in the presence of a cosmological constant
Wright, Matthew
2015-01-01
We examine charged slowly rotating perfect fluids in the presence of a cosmological constant. The asymptotic form of the vacuum solutions to the linearised Einstein-Maxwell field equations is found and the possibility of matching this vacuum to the slow rotating Garc\\'ia metric is considered. We show that, contrary to the case of zero cosmological constant, this Garc\\'ia metric can be matched to an asymptotically de Sitter vacuum in the slow rotation limit. We conclude the Garc\\'ia metric may potentially be suitable for describing a charged isolated rotating body in a cosmological background.
Discussion on some characteristics of the Charged Brane-world Black holes
Kalam, M; Ghosh, A; Raychaudhuri, B
2008-01-01
Several physical natures of charged brane-world black holes have been investigated. At first, time-like and null geodesics of the charged brane-world black holes are presented. We also analyze all the possible motions by plotting the effective potentials for various parameters for circular and radial geodesics. Secondly, we investigate the motion of test particles in the gravitational field of charged brane-world black holes using Hamilton-Jacobi (H-J) formalism. We have considered charged and uncharged test particles and examine its behavior both in static and non-static cases. Thirdly, thermodynamics of the charged brane-world black holes are studied. Finally, it has been also shown that there is no phenomenon of superradiance for an incident massless scalar field for this black hole.
Bosonic and Fermionic Entropy of (2+1)-Dimensional Charged Black Hole
Institute of Scientific and Technical Information of China (English)
CHEN Ju-Hua; WANG Yong-Jiu; JING Ji-Liang
2001-01-01
From resolving Klein-Gordon equation and Dirac equation in (2+1)-dimensional charged black hole spacetime and using 't Hooft's boundary condition and "quasi-periodic" boundary condition in the thin film brick wall model of black hole, which is introduced by LIU Weng-Biao and ZHAO Zheng, we obtain the bosonic and fermionic entropy of (2+1)-dimensional charged black hole, and find that the bosonic entropy is three times of fermionic entropy.
Charged Black Hole Solutions in Einstein-Born-Infeld gravity with a Cosmological constant
Fernando, Sharmanthie; Krug, Don
2003-01-01
We construct black hole solutions to Einstein-Born-Infeld gravity with a cosmological constant. Since an elliptic function appears in the solutions for the metric, we construct horizons numerically. The causal structure of these solutions differ drastically from their counterparts in Einstein-Maxwell gravity with a cosmological constant. The charged de-Sitter black holes can have up to three horizons and the charged anti-de Sitter black hole can have one or two depending on the parameters cho...
New Electrically Charged Black Hole in Higher Derivative Gravity as Particle Colliders
Lin, Kai; Flores-Hidalgo, G; Abdalla, E
2016-01-01
In this paper, new electrically charged asymptotically flat black hole solutions are numerically derived in the context of higher derivative gravity. These solutions can be interpreted as generalizations of two different classes of non-charged asymptotically flat spacetimes: Schwarzschild and non-Schwarzschild solutions. The possibility to use these black holes as particle colliders have been analysed. Our results show that the center-of-mass energy of two accelerated charged particles could be arbitrarily high near the event horizon of the extreme charged black hole.
The quantum emission spectra of rapidly-rotating Kerr black holes: Discrete or continuous?
Directory of Open Access Journals (Sweden)
Shahar Hod
2015-10-01
Full Text Available Bekenstein and Mukhanov (BM have suggested that, in a quantum theory of gravity, black holes may have discrete emission spectra. Using the time-energy uncertainty principle they have also shown that, for a (non-rotating Schwarzschild black hole, the natural broadening δω of the black-hole emission lines is expected to be small on the scale set by the characteristic frequency spacing Δω of the spectral lines: ζSch≡δω/Δω≪1. BM have therefore concluded that the expected discrete emission lines of the quantized Schwarzschild black hole are unlikely to overlap. In this paper we calculate the characteristic dimensionless ratio ζ(a¯≡δω/Δω for the predicted BM emission spectra of rapidly-rotating Kerr black holes (here a¯≡J/M2 is the dimensionless angular momentum of the black hole. It is shown that ζ(a¯ is an increasing function of the black-hole angular momentum. In particular, we find that the quantum emission lines of Kerr black holes in the regime a¯≳0.9 are characterized by the dimensionless ratio ζ(a¯≳1 and are therefore effectively blended together. Our results thus suggest that, even if the underlying mass (energy spectrum of these rapidly-rotating Kerr black holes is fundamentally discrete as suggested by Bekenstein and Mukhanov, the natural broadening phenomenon (associated with the time-energy uncertainty principle is expected to smear the black-hole radiation spectrum into a continuum.
Rotating black holes in a draining bathtub: superradiant scattering of gravity waves
Richartz, Mauricio; Liberati, Stefano; Weinfurtner, Silke
2014-01-01
In a draining rotating fluid flow background, surface perturbations behave as a scalar field on a rotating effective black hole spacetime. We propose a new model for the background flow which takes into account the varying depth of the water. Numerical integration of the associated Klein-Gordon equation using accessible experimental parameters shows that gravity waves in an appropriate frequency range are amplified through the mechanism of superradiance. Our numerical results suggest that the observation of this phenomenon in a common fluid mechanical system is within experimental reach. Unlike the case of wave scattering around Kerr black holes, which depends only on one dimensionless background parameter (the ratio $a/M$ between the specific angular momentum and the mass of the black hole), our system depends on two dimensionless background parameters, namely the normalized angular velocity and surface gravity at the effective black hole horizon.
Testing gravity of a regular and slowly rotating phantom black hole by quasi-periodic oscillations
Chen, Songbai; Jing, Jiliang
2016-01-01
We extend firstly the regular phantom black hole solution to a slowly rotating black hole case and find that the phantom field depresses the angular velocity of the event horizon and suppresses the super-radiation of black hole. We also probe the dependence of quasi-periodic oscillations frequencies in relativistic precession model on the phantom parameter. With the observation data of GRO J1655-40, we make a constraint on the parameters of the regular and slowly rotating phantom black hole. Our results show that although the best-fit value of the phantom parameter $b$ is small, the allowed value of $b$ in the $1\\sigma$ region is $b<0.619$, which means that the phantom theoretical model can not be excluded by the constraint from quasi-periodic oscillations with the observation data of GRO J1655-40.
Modified Newtonian potentials for particles and fluids in permanent rotation around black holes
Karas, V
2014-01-01
Modified Newtonian potentials have been proposed for the description of relativistic effects acting on particles and fluids in permanent orbital motion around black holes. Here we further discuss spherically symmetric potentials like the one proposed by Artemova, Bjornson & Novikov (1996, Astrophysical Journal, 461, 565), and we illustrate their virtues by studying the acceleration along circular trajectories. We compare the results with exact expressions in the spacetime of a rotating (Kerr) black hole.
Absorption Cross-section and Decay Rate of Rotating Linear Dilaton Black Holes
Sakalli, I
2016-01-01
We analytically study the scalar perturbation of non-asymptotically flat (NAF) rotating linear dilaton black holes (RLDBHs) in 4-dimensions. We show that both radial and angular wave equations can be solved in terms of the hypergeometric functions. The exact greybody factor (GF), the absorption cross-section (ACS), and the decay rate (DR) for the massless scalar waves are computed for these black holes (BHs). The results obtained for ACS and DR are discussed through graphs.
International Nuclear Information System (INIS)
The standard Hawking formula predicts the complete evaporation of black holes. Taking into account the effects of quantum gravity, we investigate the tunneling of fermions from a five-dimensional rotating black string. The temperature is not only determined by the string, but also affected by the quantum numbers of the emitted fermion and the effect of the extra spatial dimension. The quantum correction slows down the increase of the temperature, which naturally leads to a remnant in the evaporation. (orig.)
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.
New Electrically Charged Black Hole in Higher Derivative Gravity as Particle Colliders
Lin, Kai; Pavan, A. B.; Flores-Hidalgo, G.; Abdalla, E.
2016-01-01
In this paper, new electrically charged asymptotically flat black hole solutions are numerically derived in the context of higher derivative gravity. These solutions can be interpreted as generalizations of two different classes of non-charged asymptotically flat spacetimes: Schwarzschild and non-Schwarzschild solutions. The possibility to use these black holes as particle colliders have been analysed. Our results show that the center-of-mass energy of two accelerated charged particles could ...
Electrostatics in the Surroundings of a Topologically Charged Black Hole in the Brane
Alexis Larrañaga; Natalia Herrera; Sara Ramirez
2014-01-01
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.
Chaotic motion of particles in the accelerating and rotating black holes spacetime
Chen, Songbai; Jing, Jiliang
2016-01-01
We have investigated the motion of timelike particles along geodesic in the background of accelerating and rotating black hole spacetime. We confirmed that the chaos exists in the geodesic motion of the particles by Poincar\\'e sections, the power spectrum, the fast Lyapunov exponent indicator and the bifurcation diagram. Moreover, we probe the effects of the acceleration and rotation parameters on the chaotic behavior of a timelike geodesic particle in the black hole spacetime. Our results show that the acceleration brings richer physics for the geodesic motion of particles.
Energy extraction and particle acceleration around a rotating black hole in Horava-Lifshitz gravity
International Nuclear Information System (INIS)
The Penrose process on rotational energy extraction of the black hole in the original nonprojectable Horava-Lifshitz gravity is studied. The strong dependence of the extracted energy from the special range of parameters of the Horava-Lifshitz gravity, such as parameter ΛW and specific angular momentum a, has been found. Particle acceleration near the rotating black hole in Horava-Lifshitz gravity has been studied. It is shown that the fundamental parameter of the Horava-Lifshitz gravity can impose a limitation on the energy of the accelerating particles preventing them from the infinite value.
Khuri, Marcus A
2015-01-01
A universal inequality that bounds the charge of a body by its size is presented, and is proven as a consequence of the Einstein equations in the context of initial data sets which satisfy an appropriate energy condition. We also present a general sufficient condition for the formation of black holes due to concentration of charge, and discuss the physical relevance of these results.
Magnetic layers and neutral points near a rotating black hole
Czech Academy of Sciences Publication Activity Database
Karas, Vladimír; Kopáček, Ondřej
2009-01-01
Roč. 26, č. 2 (2009), s. 1-9. ISSN 0264-9381 R&D Projects: GA ČR GA205/07/0052 Institutional research plan: CEZ:AV0Z10030501 Keywords : black holes * magnetic fields Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics Impact factor: 3.029, year: 2009
Abramson, H A; Grossman, E B
1932-05-20
The specific rotation of egg albumin, gliadin, and gelatin (40 degrees C.) is discussed in connection with available data on (a) mobility, (b) titration curve, and (c) osmotic pressure. It seems likely that the change in specific rotation with pH of protein solutions is proportional to the change in net charge. PMID:19872669
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.
Magnetic Coupling of a Rotating Black Hole with the SurroundingAccretion Disc
Institute of Scientific and Technical Information of China (English)
汪定雄; 肖看; 雷卫华
2001-01-01
The evolution characteristics and energy extraction of a rotating black hole are investigated by considering the magnetic coupling with the surrounding accretion disc. It is found that both the mass and spin of the black hole might be reduced by the joint effects of disc accretion and magnetic coupling, provided that the latter is stronger than the former. The efficiencies of the two energy mechanisms are calculated and compared to a variety of parameters. In addition, the validity of the laws of black hole thermodynamics is discussed.
Equatorial gravitational lensing by accelerating and rotating black hole with NUT parameter
Sharif, M.; Iftikhar, Sehrish
2016-01-01
This paper is devoted to study equatorial gravitational lensing in accelerating and rotating black hole with a NUT parameter in the strong field limit. For this purpose, we first calculate null geodesic equation using the Hamilton-Jacobi separation method. We then numerically obtain deflection angle and deflection coefficients which depend on acceleration and spin parameter of the black hole. We also investigate observables in the strong field limit by taking the example of a black hole in the center of galaxy. It is concluded that acceleration parameter has a significant effect on the strong field lensing in the equatorial plane.
Rotating Kaluza-Klein Multi-Black Holes with Godel Parameter
Matsuno, Ken; Nakagawa, Toshiharu; Tomizawa, Shinya
2008-01-01
We obtain new five-dimensional supersymmetric rotating multi-Kaluza-Klein black hole solutions with the Godel parameter in the Einstein-Maxwell system with a Chern-Simons term. These solutions have no closed timelike curve outside the black hole horizons. At the infinity, the space-time is effectively four-dimensional. Each horizon admits various lens space topologies L(n;1)=S^3/Z_n in addition to a round S^3. The space-time can have outer ergoregions disjointed from the black hole horizons, as well as inner ergoregions attached to each horizon. We discuss the rich structures of ergoregions.
Regular black holes: Electrically charged solutions, Reissner-Nordstroem outside a de Sitter core
International Nuclear Information System (INIS)
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-Nordstroem, and the boundary between both regions is made of an electrically charged spherically symmetric coat. There are several types of solutions: regular nonextremal black holes with a null matter boundary, regular nonextremal black holes with a timelike matter boundary, regular extremal black holes with a timelike matter boundary, and regular overcharged stars with a timelike matter boundary. The main physical and geometrical properties of such charged regular solutions are analyzed.
Numerical models of rotating accretion flows around black holes
Igumenshchev, I V
1999-01-01
Numerical, two-dimensional, time-dependent hydrodynamical models of geometrically thick accretion discs around black holes are presented. Accretion flows with non-effective radiation cooling (ADAFs) can be both convectively stable or unstable depending on the value of the viscosity parameter \\alpha. The high viscosity flows (\\alpha~1) are stable and have a strong equatorial inflow and bipolar outflows. The low viscosity flows (\\alpha<0.1) are convectively unstable and this induces quasi-periodic variability.
Vector potential and metric perturbations of a rotating black hole
Chrzanowski, P. L.
1975-01-01
The assumption of factorized Green's functions together with the inhomogeneous Teukolsky equations are used to derive analytic expressions for homogeneous metric (and vector potential) perturbations of a Kerr black hole. These homogeneous solutions are used to construct solutions to the perturbation equations when sources are present. What one finds are particularly simple formulas for the energy and angular momentum flux in the asymptotic regions at plus or minus infinity.-
Stability of spherically symmetric, charged black holes and multipole moments for stationary systems
International Nuclear Information System (INIS)
This dissertation is written in two parts. Part I deals with the question of stability of a spherically symmetric, charged black hole against scalar, electromagnetic, and gravitational perturbations. It consists of two papers written in collaboration with Igor D. Novikov, Vernon D. Sandberg and A.A. Starobinsky. In these papers the dynamical evolution of these perturbations on the interior of a Reissner-Nordstrom black hole is described. The instability of the hole's Cauchy horizon is discussed in detail in terms of the energy densities of the test fields as measured by a freely falling observer approaching the Cauchy horizon. It is concluded that the Cauchy horizon of the analytically extended Reissner-Nordstrom solution is highly unstable and not a physical feature of a realistic gravitational collapse. Part II of this dissertation addresses two problems closely connected with multipole structure of stationary, asymptotically flat spacetimes. It consists of two papers written in collaboration with Kip S. Thorne. The first one shows the equivalence of the moments defined by Kip S. Thorne and the moments defined by Robert Geroch and Richard Hansen. The second proves a conjecture by Kip S. Thorne: In the limit of ''slow'' motion, general relativistic gravity produces no changes whatsoever in the classical Euler equations of rigid body motion. This conjecture is proved by giving an algorithm for generating rigidly rotating solutions of Einstein's equation from nonrotating, static solutions
Stability of spherically symmetric, charged black holes and multipole moments for stationary systems
Energy Technology Data Exchange (ETDEWEB)
Gursel, H.Y.
1983-01-01
This dissertation is written in two parts. Part I deals with the question of stability of a spherically symmetric, charged black hole against scalar, electromagnetic, and gravitational perturbations. It consists of two papers written in collaboration with Igor D. Novikov, Vernon D. Sandberg and A.A. Starobinsky. In these papers the dynamical evolution of these perturbations on the interior of a Reissner-Nordstrom black hole is described. The instability of the hole's Cauchy horizon is discussed in detail in terms of the energy densities of the test fields as measured by a freely falling observer approaching the Cauchy horizon. It is concluded that the Cauchy horizon of the analytically extended Reissner-Nordstrom solution is highly unstable and not a physical feature of a realistic gravitational collapse. Part II of this dissertation addresses two problems closely connected with multipole structure of stationary, asymptotically flat spacetimes. It consists of two papers written in collaboration with Kip S. Thorne. The first one shows the equivalence of the moments defined by Kip S. Thorne and the moments defined by Robert Geroch and Richard Hansen. The second proves a conjecture by Kip S. Thorne: In the limit of ''slow'' motion, general relativistic gravity produces no changes whatsoever in the classical Euler equations of rigid body motion. This conjecture is proved by giving an algorithm for generating rigidly rotating solutions of Einstein's equation from nonrotating, static solutions.
Affect of brane thickness on microscopic tidal-charged black holes
Casadio, Roberto(Dipartimento di Fisica e Astronomia, Università di Bologna, via Irnerio 46, Bologna, 40126, Italy); Harms, Benjamin; Micu, Octavian
2010-01-01
We study the phenomenological implications stemming from the dependence of the tidal charge on the brane thickness $L$ for the evaporation and decay of microscopic black holes. In general, the larger $L$, the longer are the black hole life-times and the greater their maximum mass for those cases in which the black hole can grow. In particular, we again find that tidal-charged black holes might live long enough to escape the detectors and even the gravitational field of the Earth, thus resulti...
Production of tidal-charged black holes at the Large Hadron Collider
Gingrich, Douglas M.
2010-01-01
Tidal-charged black hole solutions localized on a three-brane in the five-dimensional gravity scenario of Randall and Sundrum have been known for some time. The solutions have been used to study the decay, and growth, of black holes with initial mass of about 10 TeV. These studies are interesting in that certain black holes, if produced at the Large Hadron Collider, could live long enough to leave the detectors. I examine the production of tidal-charged black holes at the Large Hadron Collide...
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.
Intrinsic Charge Carrier Mobility in Single-Layer Black Phosphorus.
Rudenko, A N; Brener, S; Katsnelson, M I
2016-06-17
We present a theory for single- and two-phonon charge carrier scattering in anisotropic two-dimensional semiconductors applied to single-layer black phosphorus (BP). We show that in contrast to graphene, where two-phonon processes due to the scattering by flexural phonons dominate at any practically relevant temperatures and are independent of the carrier concentration n, two-phonon scattering in BP is less important and can be considered negligible at n≳10^{13} cm^{-2}. At smaller n, however, phonons enter in the essentially anharmonic regime. Compared to the hole mobility, which does not exhibit strong anisotropy between the principal directions of BP (μ_{xx}/μ_{yy}∼1.4 at n=10^{13} cm^{-2} and T=300 K), the electron mobility is found to be significantly more anisotropic (μ_{xx}/μ_{yy}∼6.2). Absolute values of μ_{xx} do not exceed 250 (700) cm^{2} V^{-1} s^{-1} for holes (electrons), which can be considered as an upper limit for the mobility in BP at room temperature. PMID:27367397
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...
Central charges and boundary fields for two dimensional dilatonic black holes
Pinamonti, N
2003-01-01
In this paper we first show that within the Hamiltonian description of general relativity, the central charge of a near horizon asymptotic symmetry group is zero, and therefore that the entropy of the system cannot be estimated using Cardy's formula. This is done by mapping a static black hole to a two dimensional plane. We explain how such a charge can only appear to a static observer who chooses to stay permanently outside the black hole. Then an alternative argument is given for the presence of a universal central charge. Finally we suggest an effective quantum theory on the horizon that is compatible with the thermodynamics behaviour of the black hole.
Low-frequency-limit conversion cross sections for charged black holes
International Nuclear Information System (INIS)
Because gravitational and electromagnetic fields are coupled in the presence of a charged black hole, such a black hole possesses a cross section for the conversion of gravitational to electromagnetic radiation and vice versa. In this paper, this phenomenon is used to consider the conversion scattering of a ''test charge'' (which is modeled as small mass, charged black hole) in a classical gravitational or electromagnetic radiation field. The total cross section for the conversion between these types of radiation is numerically calculated to be sigma/sub totconv/ = 1.33e2. Differential cross sections for incident plane or circularly polarized radiation are also exhibited
Trapping of waves and null geodesics for rotating black holes
Dyatlov, Semyon; Zworski, Maciej
2013-01-01
We present dynamical properties of linear waves and null geodesics valid for Kerr and Kerr-de Sitter black holes and their stationary perturbations. The two are intimately linked by the geometric optics approximation. For the nullgeodesic flow the key property is the r-normal hyperbolicity of the trapped set and for linear waves it is the distribution of quasi-normal modes: the exact quantization conditions do not hold for perturbations but the bounds on decay rates and the statistics of freq...
Powerful, Rotating Disk Winds from Stellar-mass Black Holes
Miller, J. M.; Fabian, A. C.; Kaastra, J.; Kallman, T.; King, A. L.; Proga, D.; Raymond, J.; Reynolds, C. S.
2015-01-01
We present an analysis of ionized X-ray disk winds observed in the Fe K band of four stellar-mass black holes observed with Chandra, including 4U 1630-47, GRO J1655-40, H 1743-322, and GRS 1915+105. High-resolution photoionization grids were generated in order to model the data. Third-order gratings spectra were used to resolve complex absorption profiles into atomic effects and multiple velocity components. The Fe XXV line is found to be shaped by contributions from the intercombination line...
Generalized uncertainty principle and entropy of three-dimensional rotating acoustic black hole
International Nuclear Information System (INIS)
Using the new equation of state density from the generalized uncertainty principle, we investigate statistics entropy of a 3-dimensional rotating acoustic black hole. When λ introduced in the generalized uncertainty principle takes a specific value, we obtain an area entropy and a correction term associated with the acoustic black hole. In this method, there does not exist any divergence and one needs not the small mass approximation in the original brick-wall model. -- Highlights: ► Statistics entropy of a 3-dimensional rotating acoustic black hole is studied. ► We obtain an area entropy and a correction term associated with it. ► We make λ introduced in the generalized uncertainty principle take a specific value. ► There does not exist any divergence in this method.
Statistical Entropy of Four-Dimensional Rotating Black Holes from Near-Horizon Geometry
International Nuclear Information System (INIS)
We show that a class of four-dimensional rotating black holes allow five-dimensional embeddings as black rotating strings. Their near-horizon geometry factorizes locally as a product of the three-dimensional anti-de Sitter space-time and a two-dimensional sphere (AdS3xS2 ), with angular momentum encoded in the global space-time structure. Following the observation that the isometries on the AdS3 space induce a two-dimensional (super)conformal field theory on the boundary, we reproduce the microscopic entropy with the correct dependence on the black hole angular momentum. copyright 1999 The American Physical Society
Rotating AdS black hole stealth solution in D=3
Hassaine, Mokhtar
2013-01-01
We show that the rotating asymptotically anti de Sitter black hole solution of new massive gravity in three dimensions can support a static stealth configuration given by a conformally coupled scalar field. By static stealth configuration, we mean a nontrivial time independent scalar field whose energy-momentum tensor vanishes identically on the rotating black hole metric solution of new massive gravity. The existence of this configuration is rendered possible because of the presence of a gravitational hair in the black hole metric that prevents the scalar field to be trivial. In the extremal case, the stealth scalar field diverges at the horizon as it occurs for the conformal scalar field of the Bocharova-Bronnikov-Melnikov-Bekenstein solution in four dimensions.
Renormalized vacuum polarization on rotating warped AdS3 black holes
Ferreira, Hugo R C
2014-01-01
We compute the renormalized vacuum polarization of a massive scalar field in the Hartle-Hawking state on (2+1)-dimensional rotating, spacelike stretched black hole solutions to Topologically Massive Gravity, surrounded by a Dirichlet mirror that makes the state well defined. The Feynman propagator is written as a mode sum on the complex Riemannian section of the spacetime, and a Hadamard renormalization procedure is implemented by matching to a mode sum on the complex Riemannian section of a rotating Minkowski spacetime. No analytic continuation in the angular momentum parameter is invoked. Selected numerical results are given, demonstrating the numerical efficacy of the method. We anticipate that this method can be extended to wider classes of rotating black hole spacetimes, in particular to the Kerr spacetime in four dimensions.
Renormalized vacuum polarization on rotating warped AdS3 black holes
Ferreira, Hugo R. C.; Louko, Jorma
2015-01-01
We compute the renormalized vacuum polarization of a massive scalar field in the Hartle-Hawking state on (2 +1 )-dimensional rotating, spacelike stretched black hole solutions to topologically massive gravity, surrounded by a Dirichlet mirror that makes the state well defined. The Feynman propagator is written as a mode sum on the complex Riemannian section of the spacetime, and a Hadamard renormalization procedure is implemented by matching to a mode sum on the complex Riemannian section of a rotating Minkowski spacetime. No analytic continuation in the angular momentum parameter is invoked. Selected numerical results are given, demonstrating the numerical efficacy of the method. We anticipate that this method can be extended to wider classes of rotating black hole spacetimes, in particular to the Kerr spacetime in four dimensions.
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
2016-04-01
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. PMID:27104693
Nonlinear Evolution and Final Fate of Charged Anti-de Sitter Black Hole Superradiant Instability
Bosch, Pablo; Green, Stephen R.; Lehner, Luis
2016-04-01
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.
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.
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 ...
Testing quantum gravity effects through Dyonic charged AdS black hole
Sadeghi, J.; Pourhassan, B.; Rostami, M.
2016-01-01
In this paper, we consider dyonic charged AdS black hole which is holographic dual of a van der Waals fluid. We use logarithmic corrected entropy and study thermodynamics of the black hole and show that holographic picture is still valid. Critical behaviors and stability also discussed. Logarithmic corrections arises due to thermal fluctuations which are important when size of black hole be small. So, thermal fluctuations interpreted as quantum effect. It means that we can see quantum effect ...
Charge loss (or the lack thereof) for AdS black holes
Yen Chin Ong; Pisin Chen
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 rat...
Tunneling of massive and charged particles from noncommutative Reissner-Nordstr\\"{o}m black hole
Nozari, Kourosh; Islamzadeh, Sara
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 ...
(Anti-) de Sitter Electrically Charged Black Hole Solutions in Higher-Derivative Gravity
Lin, Kai; Qian, Wei-Liang; 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 hol...
Instability of higher-dimensional charged black holes in the de sitter world.
Konoplya, R A; Zhidenko, A
2009-10-16
We have shown that higher-dimensional Reissner-Nordström-de Sitter black holes are gravitationally unstable for large values of the electric charge and cosmological constant in D>or=7 space-time dimensions. We have found the shape of the slightly perturbed black hole at the threshold point of instability. PMID:19905685
Hiding of the conserved (anti)baryonic charge into black holes
International Nuclear Information System (INIS)
It is shown that the total number of baryons evaporated by a black hole can differ from that of antibaryons, even if baryonic charge is microscopically conserved. The baryonic asymmetry of the Universe which can be generated by black-hole evaporation in a specific mechanism first proposed by Zeldovich is estimated
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.
A Planck-like problem for quantum charged black holes
A. FabbriBologna U. and INFN; Navarro, D. J.; Navarro-Salas, J.
2001-01-01
Motivated by the parallelism existing between the puzzles of classical physics at the beginning of the XXth century and the current paradoxes in the search of a quantum theory of gravity, we give, in analogy with Planck's black body radiation problem, a solution for the exact Hawking flux of evaporating Reissner-Nordstrom black holes. Our results show that when back-reaction effects are fully taken into account the standard picture of black hole evaporation is significantly ...
Asymptotically charged BTZ black holes in gravity's rainbow
Hendi, S. H.
2016-04-01
Motivated by the wide applications of BTZ black holes and interesting results of gravity's rainbow, we consider three dimensional rainbow solutions and investigate their thermodynamic properties. In addition to investigate black holes thermodynamics related to AdS/CFT correspondence, one may regard gravity's rainbow to encode quantum gravity effects into the black hole solutions. We take into account the various models of linear and nonlinear electrodynamics and study their effects on the gravity's rainbow spacetime. We also examine thermal stability and find that obtained three dimensional rainbow black holes are thermally stable.
Energy extraction and particle acceleration around a rotating black hole in quintessence
Oteev, Tursinbay; Abdujabbarov, Ahmadjon; Stuchlík, Zdeněk; Ahmedov, Bobomurat
2016-08-01
We study motion and collision of particles in the gravitational field of rotating black hole immersed in quintessential dark energy characterized with the quintessential parameter ωqin(-1;-1/3) governing the equation of state of the dark energy, and the dimensionless quintessential field parameter tilde{c}. We focus on the acceleration of particles due to collisional processes and show how the center of mass energy depends on the quintessential field parameter tilde{c}. We also make comparison of the obtained results to the collisional energetics of quintessential static black holes demonstrating the crucial role of the rotation parameter a in the particle acceleration. Finally we study the dependence of the maximal value of the efficiency of energy extraction through Penrose process for rotating black hole with quintessential field parameter tilde{c}. It is found that quintessence field decreases the energy extraction efficiency through Penrose process and when the parameter tilde{c} vanishes one can get the standard value of the efficiency coefficient for the Kerr black hole as η˜ 21 %.
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...
The charged black-hole bomb: A lower bound on the charge-to-mass ratio of the explosive scalar field
Shahar Hod
2016-01-01
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 stu...
Nernst Theorem and Statistical Entropy of 5-Dimensional Rotating Black Hole
Institute of Scientific and Technical Information of China (English)
ZHAO Ren; WU Yue-Qin; ZHANG Li-Chun
2003-01-01
In this paper, by using quantum statistical method, we obtain the partition function of Bose field and Fermi field on the background of the 5-dimensional rotating black hole. Then via the improved brick-wall method and membrane model, we calculate the entropy of Bose field and Fermi field of the black hole. And it is obtained that the entropy of the black hole is not only related to the area of the outer horizon but also is the function of inner horizon's area. In our results, there are not the left out term and the divergent logarithmic term in the original brick-wall method.The doubt that why the entropy of the scalar or Dirac field outside the event horizon is the entropy of the black hole in the original brick-wall method does not exist. The influence of spinning degeneracy of particles on entropy of the black hole is also given. It is shown that the entropy determined by the areas of the inner and outer horizons will approach zero,when the radiation temperature of the black hole approaches absolute zero. It satisfies Nernst theorem. The entropy can be taken as the Planck absolute entropy. We provide a way to study higher dimensional black hole.
Dynamical formation and evolution of (2+1)-dimensional charged black holes
International Nuclear Information System (INIS)
In this paper, we investigate the dynamical formation and evolution of (2 + 1)-dimensional charged black holes. We numerically study dynamical collapses of charged matter fields in an anti-de Sitter background and note the formation of black holes using the double-null formalism. Moreover, we include renormalized energy-momentum tensors assuming the S-wave approximation to determine thermodynamical back-reactions to the internal structures. If there are no semi-classical effects, the amount of charge determines the causal structures. If the charge is sufficiently small, the causal structure has a space-like singularity. However, as the charge increases, an inner Cauchy horizon appears. If we have sufficient charge, we see a space-like outer horizon and a time-like inner horizon, and if we give excessive charge, black hole horizons disappear. We have some circumstantial evidence that weak cosmic censorship is still satisfied, even for such excessive charge cases. Also, we confirm that there is mass inflation along the inner horizon, although the properties are quite different from those of four-dimensional cases. Semi-classical back-reactions will not affect the outer horizon, but they will affect the inner horizon. Near the center, there is a place where negative energy is concentrated. Thus, charged black holes in three dimensions have two types of curvature singularities in general: via mass inflation and via a concentration of negative energy. Finally, we classify possible causal structures. (paper)
The Force-Free Magnetosphere of a Rotating Black Hole
Contopoulos, Ioannis; Kazanas, Demosthenes; Papadopoulos, Demetrios B.
2013-01-01
We revisit the Blandford-Znajek process and solve the fundamental equation that governs the structure of the steady-state force-free magnetosphere around a Kerr black hole. The solution depends on the distributions of the magnetic field angular velocity and the poloidal electric current. These are not arbitrary. They are determined self-consistently by requiring that magnetic field lines cross smoothly the two singular surfaces of the problem: the inner "light surface" located inside the ergosphere and the outer "light surface" which is the generalization of the pulsar light cylinder.We find the solution for the simplest possible magnetic field configuration, the split monopole, through a numerical iterative relaxation method analogous to the one that yields the structure of the steady-state axisymmetric force-free pulsar magnetosphere. We obtain the rate of electromagnetic extraction of energy and confirm the results of Blandford and Znajek and of previous time-dependent simulations. Furthermore, we discuss the physical applicability of magnetic field configurations that do not cross both "light surfaces."
Powerful, Rotating Disk Winds from Stellar-mass Black Holes
Miller, J M; Kaastra, J; Kallman, T; King, A L; Proga, D; Raymond, J; Reynolds, C S
2015-01-01
We present an analysis of ionized X-ray disk winds observed in the Fe K band of four stellar-mass black holes observed with Chandra, including 4U 1630-47, GRO J1655-40, H 1743-322, and GRS 1915+105. High-resolution photoionization grids were generated in order to model the data. Third-order gratings spectra were used to resolve complex absorption profiles into atomic effects and multiple velocity components. The Fe XXV line is found to be shaped by contributions from the intercombination line (in absorption), and the Fe XXVI line is detected as a spin-orbit doublet. The data require 2-3 absorption zones, depending on the source. The fastest components have velocities approaching or exceeding 0.01c, increasing mass outflow rates and wind kinetic power by orders of magnitude over prior single-zone models. The first-order spectra require re-emission from the wind, broadened by a degree that is loosely consistent with Keplerian orbital velocities at the photoionization radius. This suggests that disk winds are ro...
THE FORCE-FREE MAGNETOSPHERE OF A ROTATING BLACK HOLE
International Nuclear Information System (INIS)
We revisit the Blandford-Znajek process and solve the fundamental equation that governs the structure of the steady-state force-free magnetosphere around a Kerr black hole. The solution depends on the distributions of the magnetic field angular velocity ω and the poloidal electric current I. These are not arbitrary. They are determined self-consistently by requiring that magnetic field lines cross smoothly the two singular surfaces of the problem: the inner ''light surface'' located inside the ergosphere and the outer ''light surface'' which is the generalization of the pulsar light cylinder. We find the solution for the simplest possible magnetic field configuration, the split monopole, through a numerical iterative relaxation method analogous to the one that yields the structure of the steady-state axisymmetric force-free pulsar magnetosphere. We obtain the rate of electromagnetic extraction of energy and confirm the results of Blandford and Znajek and of previous time-dependent simulations. Furthermore, we discuss the physical applicability of magnetic field configurations that do not cross both ''light surfaces''.
THE FORCE-FREE MAGNETOSPHERE OF A ROTATING BLACK HOLE
Energy Technology Data Exchange (ETDEWEB)
Contopoulos, Ioannis [Research Center for Astronomy, Academy of Athens, Athens 11527 (Greece); Kazanas, Demosthenes [NASA/GSFC, Code 663, Greenbelt, MD 20771 (United States); Papadopoulos, Demetrios B., E-mail: icontop@academyofathens.gr, E-mail: demos.kazanas@nasa.gov, E-mail: papadop@astro.auth.gr [Department of Physics, Aristotle University of Thessaloniki, Thessaloniki 54124 (Greece)
2013-03-10
We revisit the Blandford-Znajek process and solve the fundamental equation that governs the structure of the steady-state force-free magnetosphere around a Kerr black hole. The solution depends on the distributions of the magnetic field angular velocity {omega} and the poloidal electric current I. These are not arbitrary. They are determined self-consistently by requiring that magnetic field lines cross smoothly the two singular surfaces of the problem: the inner ''light surface'' located inside the ergosphere and the outer ''light surface'' which is the generalization of the pulsar light cylinder. We find the solution for the simplest possible magnetic field configuration, the split monopole, through a numerical iterative relaxation method analogous to the one that yields the structure of the steady-state axisymmetric force-free pulsar magnetosphere. We obtain the rate of electromagnetic extraction of energy and confirm the results of Blandford and Znajek and of previous time-dependent simulations. Furthermore, we discuss the physical applicability of magnetic field configurations that do not cross both ''light surfaces''.
An axisymmetric charged dust distribution with NUT rotation in general relativity
Vargas-Rodriguez, H.; Gonzalez-Silva, R. A.; Lopez Benitez, L. I.
2010-07-01
An exact solution of the Einstein-Maxwell's field equations is presented. This solution describes an axisymmetric charged dust distribution, with NUT rotation, in the presence of an electromagnetic field of the pure magnetic type. In the comoving reference frame, there is magnetic field only, the dust's electric charges do not interact with themselves, this is due to the vanishing of the Lorentz force. A naked singularity with magnetic charge is present. The solution is of the Petrov type D and possesses four Killing vectors. This is a generalization of the Lukács solution to the case when dust is charged.
Yang, Huan
2014-01-01
In this paper we study wave propagation and scattering near a rotating black hole. In particular, we assume a coherent emission source near the black hole and investigate the wavefront distortion as seen by a distant observer. Near the observer, the propagating wave can be decomposed using the Laguerre-Gaussian mode basis and its wavefront distortion can be characterized by the decomposition coefficient. We find that this decomposition spectrum is symmetric for wave sources located near a Schwarzschild black hole, but is generically asymmetric if the host black hole is rotating. The spectrum asymmetry, or the net orbital angular momentum carried by the wave, is intimately related to the black hole spin and mass, the wave frequency and the locations of the source and the observer. We present semi-analytical expressions and numerical results for these parameter-dependences. If the radiation is temporally coherent, our results show that the secondary images of the source can be almost as bright as its primary im...
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.
Critical phenomena in higher curvature charged AdS black holes
Arindam Lala
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 ...
Nucleic Acid Charge Transfer: Black, White and Gray
Venkatramani, Ravindra; Keinan, Shahar; Balaeff, Alexander; Beratan, David N.
2011-01-01
Theoretical studies of charge transport in deoxyribonucleic acid (DNA) and peptide nucleic acid (PNA) indicate that structure and dynamics modulate the charge transfer rates, and that different members of a structural ensemble support different charge transport mechanisms. Here, we review the influences of nucleobase geometry, electronic structure, solvent environment, and thermal conformational fluctuations on the charge transfer mechanism. We describe an emerging framework for understanding...
On the variable-charged black holes embedded into de Sitter space: Hawking's radiation
Ibohal, Ng.
2004-01-01
In this paper we study the Hawking evaporation of masses of variable-charged Reissner-Nordstrom and Kerr-Newman, black holes embedded into the de Sitter universe by considering the charge to be function of radial coordinate of the spherically symmetric metric.
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.
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.
Quantum electron levels in the field of a charged black hole
Dokuchaev, V. I.; Eroshenko, Yu. N.
2015-12-01
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.
Quantum electron levels in the field of a charged black hole
International Nuclear Information System (INIS)
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
Phase Transition of the Higher Dimensional Charged Gauss-Bonnet Black Hole in de Sitter Spacetime
International Nuclear Information System (INIS)
We study the phase transition of charged Gauss-Bonnet-de Sitter (GB-dS) black hole. For black holes in de Sitter spacetime, there is not only black hole horizon, but also cosmological horizon. The thermodynamic quantities on both horizons satisfy the first law of the black hole thermodynamics, respectively; moreover, there are additional connections between them. Using the effective temperature approach, we obtained the effective thermodynamic quantities of charged GB-dS black hole. According to Ehrenfest classification, we calculate some response functions and plot their figures, from which one can see that the spacetime undergoes a second-order phase transition at the critical point. It is shown that the critical values of effective temperature and pressure decrease with the increase of the value of GB parameter α
Gravitational perturbation induced by a rotating ring around a Kerr black hole
Sano, Yasumichi
2014-01-01
The linear perturbation of a Kerr black hole induced by a rotating massive circular ring is discussed by using the formalism by Teukolsky, Chrzanowski, Cohen and Kegeles. In these formalism, the perturbed Weyl scalars, $\\psi_0$ and $\\psi_4$, are first obtained from the Teukolsky equation. The perturbed metric is obtained in a radiation gauge via the Hertz potential. The computation can be done in the same way as in our previous paper, in which we considered the perturbation of a Schwarzschild black hole induced by a rotating ring. By adding lower multipole modes such as mass and angular momentum perturbation which are not computed by the Teukolsky equation, and by appropriately setting the parameters which are related to the gauge freedom, we obtain the perturbed gravitational field which is smooth except on the equatorial plane outside the ring.
Thermodynamics of rotating black branes in gravity with first order string corrections
Directory of Open Access Journals (Sweden)
M. H. Dehghani
2005-09-01
Full Text Available In this paper, the rotating black brane solutions with zero curvature horizon of classical gravity with first order string corrections are introduced. Although these solutions are not asymptotically anti de Sitter, one can use the counterterm method in order to compute the conserved quantities of these solutions. Here, by reviewing the counterterm method for asymptotically anti de Sitter spacetimes, the conserved quantities of these rotating solutions are computed. Also a Smarr-type formula for the mass as a function of the entropy and the angular momenta is obtained, and it is shown that the conserved and thermodynamic quantities satisfy the first law of thermodynamics. Finally, a stability analysis in the canonical ensemble is performed, and it is shown that the system is thermally stable. This is in commensurable with the fact that there is no Hawking-Page phase transition for black object with zero curvature horizon.
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.
Schwinger effect in (A)dS and charged black hole
Kim, Sang Pyo
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.
Charged spinning black holes as accelerators of spinning particles
Zhang, Yu-Peng; Wei, Shao-Wen; Yang, Jie; Liu, Yu-Xiao
2016-01-01
It is well known that some black holes can act as accelerators for particles without spin. Recently, there are some works considering collision of two spinning particles in the background of Schwarzschild and Kerr black holes and it was shown that the spin of the test particles is related to the center-of-mass energy. In this paper we extend the results to some more general cases. We consider Kerr-Newman black holes as accelerators for spinning particles. We derive the center-of-mass energy of the spinning particles and use numerical method to investigate how the center-of-mass energy is affected by the properties of the black holes and spinning particles.
Thermodynamic instability of nonlinearly charged black holes in gravity's rainbow
Hendi, S H; Panah, B Eslam; Momennia, M
2015-01-01
Motivated by the violation of Lorentz invariancy 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 related metric functions and electric fields. We show that there is an essential singularity at the origin which is covered with 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 thermal stability conditions for these black hole solutions in context of canonical ensemble. We show that although there is not physical small black hole, large black holes are physical and enjoy thermal stability in gravity's rainbow.
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...
Analytic solutions of the geodesic equation for U(1)^2 dyonic rotating black holes
Flathmann, Kai
2016-01-01
In this article we derive the geodesic equations in the $\\text{U(1)}^2$ dyonic rotating black hole spacetime. We present their solutions in terms of the Kleinian $\\sigma$-function and in special cases in terms of the Weierstra{\\ss} $\\wp$-, $\\sigma$- and $\\zeta$-functions. To give a list of all possible orbits, we analyse the geodesic motion of test particles and light using parametric diagrams and effective potentials.
Hawking Radiation of Spin-1 Particles From Three Dimensional Rotating Hairy Black Hole
Sakalli, I
2015-01-01
In the present article, we study the Hawking radiation (HR) of spin-1 particles -- so-called vector particles -- from a three dimensional (3D) rotating black hole with scalar hair (RBHWSH) using Hamilton-Jacobi (HJ) ansatz. Putting the Proca equation amalgamated with the WKB approximation in process, the tunneling spectrum of vector particles is obtained. We recover the standard Hawking temperature corresponding to the emission of these particles from RBHWSH.
Hidden symmetries and integrability in higher dimensional rotating black hole spacetimes
Energy Technology Data Exchange (ETDEWEB)
Cariglia, M. [Universidade Federal de Ouro Preto, ICEB, Departamento de Fisica. Campus Morro do Cruzeiro, Morro do Cruzeiro, Ouro Preto, MG (Brazil); Krtous, P. [Institute of Theoretical Physics, Faculty of Mathematics and Physics, Charles University, V Holesovickach 2, Prague (Czech Republic); Kubiznak, D. [Perimeter Institute, 31 Caroline St. N. Waterloo Ontario, N2L 2Y5 (Canada)
2012-07-15
This is a short pedagogical introduction to the subject of Killing-Staeckel and Killing-Yano tensors and their role in the integrability of various types of equations that are of physical interest in curved space-time, the main application being higher dimensional rotating black holes with cosmological constant. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)
Modified Newtonian potentials for particles and fluids in permanent rotation around black holes
Karas, V.; Abramowicz, M. A.
2014-01-01
Modified Newtonian potentials have been proposed for the description of relativistic effects acting on particles and fluids in permanent orbital motion around black holes. Here we further discuss spherically symmetric potentials like the one proposed by Artemova, Bjornson & Novikov (1996, Astrophysical Journal, 461, 565), and we illustrate their virtues by studying the acceleration along circular trajectories. We compare the results with exact expressions in the spacetime of a rotating (Kerr)...
Hidden symmetries and integrability in higher dimensional rotating black hole spacetimes
International Nuclear Information System (INIS)
This is a short pedagogical introduction to the subject of Killing-Staeckel and Killing-Yano tensors and their role in the integrability of various types of equations that are of physical interest in curved space-time, the main application being higher dimensional rotating black holes with cosmological constant. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)
Dualities in D=5, N=2 supergravity, black hole entropy, and AdS central charges
International Nuclear Information System (INIS)
The issue of microstate counting for general black holes in D=5, N=2 supergravity coupled to vector multiplets is discussed from various viewpoints. The statistical entropy is computed for the near-extremal case by using the central charge appearing in the asymptotic symmetry algebra of AdS2. Furthermore, we show that the considered supergravity theory enjoys a duality invariance which connects electrically charged black holes and magnetically charged black strings. The near-horizon geometry of the latter turns out to be AdS3 x S2, which allows a microscopic calculation of their entropy using the Brown-Hennaux central charges in Cardy's formula. In both approaches we find perfect agreement between statistical and thermodynamical entropy. (orig.)
QPOs from Random X-ray Bursts around Rotating Black Holes
Kukumura, Keigo; Kazanas, Demosthenes; Stephenson, Gordon
2009-01-01
We continue our earlier studies of quasi-periodic oscillations (QPOs) in the power spectra of accreting, rapidly-rotating black holes that originate from the geometric 'light echoes' of X-ray flares occurring within the black hole ergosphere. Our present work extends our previous treatment to three-dimensional photon emission and orbits to allow for arbitrary latitudes in the positions of the distant observers and the X-ray sources in place of the mainly equatorial positions and photon orbits of the earlier consideration. Following the trajectories of a large number of photons we calculate the response functions of a given geometry and use them to produce model light curves which we subsequently analyze to compute their power spectra and autocorrelation functions. In the case of an optically-thin environment, relevant to advection-dominated accretion flows, we consistently find QPOs at frequencies of order of approximately kHz for stellar-mass black hole candidates while order of approximately mHz for typical active galactic nuclei (approximately equal to 10(exp 7) solar mass) for a wide range of viewing angles (30 degrees to 80 degrees) from X-ray sources predominantly concentrated toward the equator within the ergosphere. As in out previous treatment, here too, the QPO signal is produced by the frame-dragging of the photons by the rapidly-rotating black hole, which results in photon 'bunches' separated by constant time-lags, the result of multiple photon orbits around the hole. Our model predicts for various source/observer configurations the robust presence of a new class of QPOs, which is inevitably generic to curved spacetime structure in rotating black hole systems.
Observational test for the existence of a rotating black hole in Cyg X-1
International Nuclear Information System (INIS)
It is stated that the degree and plane of linear polarisation of the radiation from Cyg X-1 are being investigated by X-ray satellite experiments. This radiation can be explained as coming from an accretion disk around a black hole, the polarisation of the X-rays being due to electron scattering in the hotter inner regions of the disk. Existing predictions of the polarisation properties, as a function of energy, have been based on a Newtonian approximation, thus neglecting gravitational effects on the rays as they propagate from the surface of the disk to an observer at infinity. Preliminary results are here given of a full general relativistic calculation that shows that gravitational effects completely alter the polarisation properties, and provide a sensitive test of the existence of a black hole. It is found that for a rapidly rotating black hole the general relativistic effects on the polarisation properties are an order of magnitude greater than for a slowly rotating black hole, or for a neutron star. The degree of linear polarisation of the rays as they leave the disk will also differ from the Newtonian value, and gravitational bending of the light will alter the angle at which a ray leaves the surface of the disk. The large general relativistic variation of the polarisation plane with energy is illustrated graphically. The very large general relativistic rotations in the plane of polarisation provide an opportunity for testing the black hole hypothesis for Cyg X-1. In order to observe these effects X-ray satellite experiments will be required with more sensitive polarimetry across a wider energy range than is available at present. (U.K.)
Higher dimensional charged $f(R)$ black holes
Sheykhi, Ahmad
2012-01-01
We construct a new class of higher dimensional black hole solutions of $f(R)$ theory coupled to a nonlinear Maxwell field. In deriving these solutions the traceless property of the energy-momentum tensor of the matter filed plays a crucial role. In $n$-dimensional spacetime the energy-momentum tensor of conformally invariant Maxwell field is traceless provided we take $n=4p$, where $p$ is the power of conformally invariant Maxwell lagrangian. These black hole solutions are similar to higher dimensional Reissner-Nordstrom AdS black holes but only exist for dimensions which are multiples of four. We calculate the conserved and thermodynamic quantities of these black holes and check the validity of the first law of black hole thermodynamics by computing a Smarr-type formula for the total mass of the solutions. Finally, we study the local stability of the solutions and find that there is indeed a phase transition for higher dimensional $f(R)$ black holes with conformally invariant Maxwell source.
Higher-dimensional charged f(R) black holes
Sheykhi, Ahmad
2012-07-01
We construct a new class of higher-dimensional black hole solutions of f(R) theory coupled to a nonlinear Maxwell field. In deriving these solutions the traceless property of the energy-momentum tensor of the matter filed plays a crucial role. In n-dimensional spacetime the energy-momentum tensor of conformally invariant Maxwell field is traceless provided we take n=4p, where p is the power of conformally invariant Maxwell Lagrangian. These black hole solutions are similar to higher-dimensional Reissner-Nordstrom anti-de Sitter black holes but only exist for dimensions which are multiples of four. We calculate the conserved and thermodynamic quantities of these black holes and check the validity of the first law of black hole thermodynamics by computing a Smarr-type formula for the total mass of the solutions. Finally, we study the local stability of the solutions and find that there is indeed a phase transition for higher-dimensional f(R) black holes with conformally invariant Maxwell source.
Constraints on dark matter particles charged under a hidden gauge group from primordial black holes
Dai, De-Chang; Freese, Katherine; Stojkovic, Dejan
2009-01-01
In order to accommodate increasingly tighter observational constraints on dark matter, several models have been proposed recently in which dark matter particles are charged under some hidden gauge group. Hidden gauge charges are invisible for the standard model particles, hence such scenarios are very difficult to constrain directly. However black holes are sensitive to all gauge charges, whether they belong to the standard model or not. Here, we examine the constraints on the possible values...
Stability of spherically symmetric, charged black holes and multipole moments for stationary systems
Gursel, Yekta
This dissertation is written in two parts. Part I deals with the question of stability of a spherically symmetric, charged black hole against scalar, electromagnetic, and gravitational perturbations. It consists of two papers written in collaboration with Igor D. NoVikov, Vernon D. Sandberg and A. A. Starobinsky. In these papers we describe the dynamical evolution of these perturbations on the interior of a Reissner-Nordstrom black hole. The instability of the hole's Cauchy horizon is discussed in detail in terms of the energy densities of the test fields as measured by a freely falling observer approaching the Cauchy horizon. We conclude that the Cauchy horizon of the analytically extended Reissner-Nordstrom solution is highly unstable and not a physical feature of a realistic gravitational collapse. Part II of this dissertation addresses two problems closely connected with muitipole structure of stationary, asymptotically flat spacetimes. It consists of two papers written in collaboration with Kip S. Thorne despite the fact that his name does not appear on one of them. The first one (Paper III in this thesis) shows the equivalence of the moments defined by Kip S. Thorne and the moments defined by Robert Geroch and Richard Hansen. The second (Paper IV in this thesis) proves a conjecture by Kip S. Thorne: In the limit of "slow" motion, general relativistic gravity produces no changes whatsoever in the classical Euler equations of rigid body motion. We prove this conjecture by giving an algorithm for generating rigidly rotating solutions of Einstein's equations from nonrotating, static solutions.
Spinning charged test particles and Cosmic Censorship
International Nuclear Information System (INIS)
The authors consider spinning charged test particles in the gravitational field of a rotating charged black hole, and it is shown that the hole cannot be destroyed, according to the Cosmic Censorship hypothesis. (Auth.)
Charged massive particle at rest in the field of a Reissner-Nordstroem black hole
International Nuclear Information System (INIS)
The interaction of a Reissner-Nordstroem black hole and a charged massive particle is studied in the framework of perturbation theory. The particle backreaction is taken into account, studying the effect of general static perturbations of the hole following the approach of Zerilli. The solutions of the combined Einstein-Maxwell equations for both perturbed gravitational and electromagnetic fields to first order of the perturbation are exactly reconstructed by summing all multipoles, and are given explicit closed form expressions. The existence of a singularity-free solution of the Einstein-Maxwell system requires that the charge-to-mass ratios of the black hole and of the particle satisfy an equilibrium condition which is in general dependent on the separation between the two bodies. If the black hole is undercritically charged (i.e. its charge-to-mass ratio is less than one), the particle must be overcritically charged, in the sense that the particle must have a charge-to-mass ratio greater than one. If the charge-to-mass ratios of the black hole and of the particle are both equal to one (so that they are both critically charged, or 'extreme'), the equilibrium can exist for any separation distance, and the solution we find coincides with the linearization in the present context of the well-known Majumdar-Papapetrou solution for two extreme Reissner-Nordstroem black holes. In addition to these singularity-free solutions, we also analyze the corresponding solution for the problem of a massive particle at rest near a Schwarzschild black hole, exhibiting a strut singularity on the axis between the two bodies. The relations between our perturbative solutions and the corresponding exact two-body solutions belonging to the Weyl class are also discussed
Buoyancy and the Penrose process produce jets from rotating black holes
Semenov, V. S.; Dyadechkin, S. A.; Heyn, M. F.
2014-04-01
The exact mechanism by which astrophysical jets are formed is still unknown. It is believed that the necessary elements consist of a rotating (Kerr) black hole and a magnetized accreting plasma. We model the accreting plasma as a collection of magnetic flux tubes/strings. If such a tube falls into a Kerr black hole, then the leading portion loses angular momentum and energy as the string brakes. To compensate for this loss, momentum and energy is redistributed to the trailing portion of the tube. We found that buoyancy creates a pronounced helical magnetic field structure aligned with the spin axis. Along the field lines, the plasma is centrifugally accelerated close to the speed of light. This process leads to unlimited stretching of the flux tube since one part of the tube continues to fall into the black hole and, simultaneously, the other part of the string is pushed outward. Eventually, reconnection cuts the tube. The inner part is filled with new material and the outer part forms a collimated bubble-structured relativistic jet. Each plasmoid can be considered as an outgoing particle in the Penrose mechanism: it carries extracted rotational energy away from the black hole while the falling part, with corresponding negative energy, is left inside the ergosphere.
Constraints on dark matter particles charged under a hidden gauge group from primordial black holes
International Nuclear Information System (INIS)
In order to accommodate increasingly tighter observational constraints on dark matter, several models have been proposed recently in which dark matter particles are charged under some hidden gauge group. Hidden gauge charges are invisible for the standard model particles, hence such scenarios are very difficult to constrain directly. However black holes are sensitive to all gauge charges, whether they belong to the standard model or not. Here, we examine the constraints on the possible values of the dark matter particle mass and hidden gauge charge from the evolution of primordial black holes. We find that the existence of the primordial black holes with reasonable mass is incompatible with dark matter particles whose charge to mass ratio is of the order of one. For dark matter particles whose charge to mass ratio is much less than one, we are able to exclude only heavy dark matter in the mass range of 1011 GeV–1016 GeV. Finally, for dark matter particles whose charge to mass ratio is much greater than one, there are no useful limits coming from primordial black holes
International Nuclear Information System (INIS)
The energy content of the Lee-Kim-Myung slowly-rotating black hole (Lee et al., Eur. Phys. J. C 70, 361 (2010)), in the Horava-Lifshitz (HL) theory of gravity is investigated by using approximate Lie symmetry methods for differential equations. The energy of this slowly-rotating black hole in the HL gravity is found to be is rescaled by a r-dependent factor. From the rescaling of energy, the rotation is observed to be added to the mass of the black hole, and this effect decreases with increasing coordinate r. This expression of energy rescaling reduces to the Schwarzschild mass for the limits in which the Lee-Kim-Myung slowly rotating black hole solution in the HL gravity reduces to the Schwarzschild solution in general relativity.
International Nuclear Information System (INIS)
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.)
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.)
Rahaman, Farook; Bhar, Piyali; Sharma, Ranjan; Tiwari, Rishi Kumar
2015-01-01
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.
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 ...
Probing spacetime noncommutative constant via charged astrophysical black hole lensing
Ding, Chikun; Jing, Jiliang
2011-10-01
We study the influence of the spacetime noncommutative parameter on the strong field gravitational lensing in the noncommutative Reissner-Nordström black-hole spacetime. Supposing that the gravitational field of the supermassive central object of the Galaxy is described by this metric, we estimate the numerical values of the coefficients and observables for strong gravitational lensing. Our results show that with the increase of the parameter sqrt {\\vartheta } , the observables θ ∞ and r m decrease, while s increases. Our results also show that i) if sqrt {\\vartheta } is strong, the observables are close to those of the noncommutative Schwarzschild black hole lensing; ii) if sqrt {\\vartheta } is weak, the observables are close to those of the commutative Reissner-Nordström black hole lensing; iii) the detectable scope of ϑ in a noncommutative Reissner-Nordström black hole lensing is 0.12 ≤ sqrt {\\vartheta } ≤ 0.26 , which is wider than that in a noncommutative Schwarzschild black hole lensing, 0.18 ≤ sqrt {\\vartheta } ≤ 0.26 . This may offer a way to probe the spacetime noncommutative constant ϑ by the astronomical instruments in the future.
Energy Technology Data Exchange (ETDEWEB)
Stuchlik, Zdenek; Kolos, Martin [Silesian University in Opava, Faculty of Philosophy and Science, Institute of Physics and Research Centre of Theoretical Physics and Astrophysics, Opava (Czech Republic)
2016-01-15
To test the role of large-scale magnetic fields in accretion processes, we study the dynamics of the charged test particles in the vicinity of a black hole immersed into an asymptotically uniform magnetic field. Using the Hamiltonian formalism of the 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 of the charged particle dynamics provides a 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 a 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 largest and it can be ultra-relativistic. We discuss the consequences of the model of ionization of test particles forming a neutral accretion disc, or heavy ions following off-equatorial circular orbits, and we explore the fate of heavy charged test particles after ionization where no kick of heavy ions is assumed and only the switch-on effect of the magnetic field is relevant. We demonstrate that acceleration and escape of the ionized particles can be efficient along the Kerr black hole symmetry axis parallel to the magnetic field lines. We show that a strong acceleration of the ionized particles to ultra-relativistic velocities is preferred in the direction close to the magnetic field lines. Therefore, the process of ionization of Keplerian discs around the Kerr black holes can serve as a model of relativistic jets. (orig.)
International Nuclear Information System (INIS)
To test the role of large-scale magnetic fields in accretion processes, we study the dynamics of the charged test particles in the vicinity of a black hole immersed into an asymptotically uniform magnetic field. Using the Hamiltonian formalism of the 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 of the charged particle dynamics provides a 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 a 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 largest and it can be ultra-relativistic. We discuss the consequences of the model of ionization of test particles forming a neutral accretion disc, or heavy ions following off-equatorial circular orbits, and we explore the fate of heavy charged test particles after ionization where no kick of heavy ions is assumed and only the switch-on effect of the magnetic field is relevant. We demonstrate that acceleration and escape of the ionized particles can be efficient along the Kerr black hole symmetry axis parallel to the magnetic field lines. We show that a strong acceleration of the ionized particles to ultra-relativistic velocities is preferred in the direction close to the magnetic field lines. Therefore, the process of ionization of Keplerian discs around the Kerr black holes can serve as a model of relativistic jets. (orig.)
Effective action for the field equations of charged black holes
International Nuclear Information System (INIS)
We consistently reduce the equations of motion for the bosonic N = 2 supergravity action, using a multi-centered black hole ansatz for the metric. This reduction is done in a general, non-supersymmetric setup, in which we extend concepts of BPS black hole technology. First we obtain a more general form of the black hole potential, as part of an effective action for both the scalars and the vectors in the supergravity theory. Furthermore, we show that there are extra constraints specifying the solution, which we calculate explicitly. In the literature, these constraints have already been studied in the one-center case. We also show that the effective action we obtain for non-static metrics can be linked to the 'entropy function' for the spherically symmetric case, as defined by Sen (2005 J. High Energy Phys. JHEP09(2005)038) and Cardoso et al (2007 J. High Energy Phys. JHEP03(2007)085)
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.
Regular black holes: Guilfoyle's electrically charged solutions with a perfect fluid phantom core
Lemos, José P. S.; Zanchin, Vilson T.
2016-06-01
Regular black hole solutions are found among the Guilfoyle exact solutions. These are spherically symmetric solutions of general relativity coupled to Maxwell's electromagnetism and charged matter where the metric potentials and electromagnetic fields are related in some particularly simple form. We show that, for certain ranges of the parameters, there are objects which correspond to regular charged black holes, whose interior region is filled by an electrically charged phantomlike fluid, or, in the limiting case, a de Sitter false vacuum fluid, and whose exterior region is Reissner-Nordström. The boundary between both regions is a smooth boundary surface, except in the limiting case where the boundary is made of a massless electrically charged spherically symmetric coat. The main physical and geometrical properties of such charged regular solutions are analyzed.
Regular black holes: Guilfoyle electrically charged solutions with a perfect fluid phantom core
Lemos, José P S
2016-01-01
Regular black hole solutions are found among the Guilfoyle exact solutions. These are spherically symmetric solutions of general relativity coupled to Maxwell's electromagnetism and charged matter where the metric potentials and electromagnetic fields are related in some particularly simple form. We show that, for certain ranges of the parameters, there are objects which correspond to regular charged black holes, whose interior region is filled by an electrically charged phantom-like fluid, or, in the limiting case, a de Sitter false vacuum fluid, and whose exterior region is Reissner-Nordstr\\"om. The boundary between both regions is a smooth boundary surface, except in the limiting case where the boundary is made of a massless electrically charged spherically symmetric coat. The main physical and geometrical properties of such charged regular solutions are analyzed.
A rotating hairy AdS$_3$ black hole with the metric having only one Killing vector field
Iizuka, Norihiro; Maeda, Kengo
2015-01-01
We perturbatively construct a three-dimensional rotating AdS black hole with a real scalar hair. We choose the mass of a scalar field slightly above the Breitenlohner-Freedman bound and impose a more general boundary condition for the bulk scalar field at AdS infinity. We first show that rotating BTZ black holes are unstable against superradiant modes under our more general boundary condition. Next we construct a rotating hairy black hole perturbatively with respect to a small amplitude $\\epsilon$ of the scalar field, up to $O(\\epsilon^4)$. The lumps of non-linearly perturbed geometry admit only one Killing vector field and co-rotate with the black hole, and it shows no dissipation. We numerically show that the entropy of our hairy black hole is larger than that of the BTZ black hole with the same energy and the angular momentum. This indicates, at least in the perturbative level, that our rotating hairy black hole in lumpy geometry can be the endpoint of the superradiant instability.
Near-horizon circular orbits and extremal limit for dirty rotating black holes
Zaslavskii, O. B.
2015-08-01
We consider generic rotating axially symmetric "dirty" (surrounded by matter) black holes. Near-horizon circular equatorial orbits are examined in two different cases of near-extremal (small surface gravity κ ) and exactly extremal black holes. This has a number of qualitative distinctions. In the first case, it is shown that such orbits can lie as close to the horizon as one wishes on suitably chosen slices of space-time when κ →0 . This generalizes the observation of T. Jacobson [Classical Quantum Gravity 28, 187001 (2011), 10.1088/0264-9381/28/18/187001] made for the Kerr metric. If a black hole is extremal (κ =0 ), circular on-horizon orbits are impossible for massive particles but, in general, are possible in its vicinity. The corresponding black hole parameters determine also the rate with which a fine-tuned particle on the noncircular near-horizon orbit asymptotically approaches the horizon. Properties of orbits under discussion are also related to the Bañados-Silk-West effect of high energy collisions near black holes. Impossibility of the on-horizon orbits in question is manifestation of kinematic censorship that forbids infinite energies in collisions.
The 2+1 charged black hole in topologically massive Electrodynamics
Andrade, T; Benguria, R; Gomberoff, A
2005-01-01
The 2+1 black hole coupled to a Maxwell field can be charged in two different ways. On the one hand, it can support a Coulomb field whose potential grows logarithmically in the radial coordinate. On the other, due to the existence of a non-contractible cycle, it also supports a topological charge whose value is given by the corresponding Abelian holonomy. Only the Coulomb charge, however, is given by a constant flux integral with an associated continuity equation. The topological charge does not gravitate and is somehow decoupled from the black hole. This situation changes abruptly if one turns on the Chern-Simons term for the Maxwell field. First, the flux integral at infinity becomes equal to the topological charge. Second, demanding regularity of the black hole horizon, it is found that the Coulomb charge (whose associated potential now decays by a power law) must vanish identically. Hence, in 2+1 topologically massive electrodynamics coupled to gravity, the black hole can only support holonomies for the M...
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.
Pani, Paolo; Berti, Emanuele; Gualtieri, Leonardo
2013-06-14
The most general stationary black-hole solution of Einstein-Maxwell theory in vacuum is the Kerr-Newman metric, specified by three parameters: mass M, spin J, and charge Q. Within classical general relativity, one of the most important and challenging open problems in black-hole perturbation theory is the study of gravitational and electromagnetic fields in the Kerr-Newman geometry, because of the indissoluble coupling of the perturbation functions. Here we circumvent this long-standing problem by working in the slow-rotation limit. We compute the quasinormal modes up to linear order in J for any value of Q and provide the first, fully consistent stability analysis of the Kerr-Newman metric. For scalar perturbations the quasinormal modes can be computed exactly, and we demonstrate that the method is accurate within 3% for spins J/J(max) ≲ 0.5, where J(max) is the maximum allowed spin for any value of Q. Quite remarkably, we find numerical evidence that the axial and polar sectors of the gravitoelectromagnetic perturbations are isospectral to linear order in the spin. The extension of our results to nonasymptotically flat space-times could be useful in the context of gauge-gravity dualities and string theory. PMID:25165905
Pani, Paolo; Gualtieri, Leonardo
2013-01-01
The most general stationary black-hole solution of Einstein-Maxwell theory in vacuum is the Kerr-Newman metric, specified by three parameters: mass M, spin J and charge Q. Within classical general relativity, the most important and challenging open problem in black-hole perturbation theory is the study of gravitational and electromagnetic fields in the Kerr-Newman geometry, because of the indissoluble coupling of the perturbation functions. Here we circumvent this long-standing problem by working in the slow-rotation limit. We compute the quasinormal modes up to linear order in J for any value of Q and provide the first, fully-consistent stability analysis of the Kerr-Newman metric. For scalar perturbations the quasinormal modes can be computed exactly, and we demonstrate that the method is accurate within 3% for spins J/Jmax<~0.5, where Jmax is the maximum allowed spin for any value of Q. Quite remarkably, we find numerical evidence that the axial and polar sectors of the gravito-electromagnetic perturbat...
Shaymatov, Sanjar; Ahmedov, Bobomurat; Joshi, Pankaj S
2014-01-01
We investigate effect of a test magnetic field on the process of destroying near-extremal Kerr black hole with a charged test particle. It has been shown that it would be possible to throw a charged test particle into the near extremal rotating black hole and make it go past the extremality i.e. turn Kerr black hole into the Kerr-Newmann naked singularity. Typically in an astrophysical scenario black holes are believed to be surrounded by a magnetic field. Magnetic field although small, affects motion of charged particles drastically due to the large Lorentz force, as the electromagnetic force is much stronger that the gravity. Thus a test magnetic field can affect the process of destroying black holes and restore the cosmic censorship in the astrophysical context. We show that a test magnetic field would act as a cosmic censor beyond a certain threshold value. We try to gauge the magnitude of the magnetic field by comparing its energy density with that of the change in the curvature induced by the test parti...
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.
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.
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.
(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.
(Anti-) de Sitter electrically charged black-hole solutions in higher-derivative gravity
Lin, Kai; Qian, Wei-Liang; Pavan, A. B.; Abdalla, E.
2016-06-01
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.
Charged Fermions Tunnel from the Kerr-Newman Black Hole Influenced by Quantum Gravity Effects
Ren, Ruyi; Chen, Deyou; Pu, Jin
2016-03-01
Taking into account quantum gravity effects, we investigate the tunnelling radiation of charged fermions in the Kerr-Newman black hole. The result shows that the corrected Hawking temperature is determined not only by the parameters of the black hole, but also by the energy, angular momentum and mass of the emitted fermion. Meanwhile, an interesting found is that the temperature is affected by the angle 𝜃. The quantum gravity correction slows down the evaporation.
Strong deflection lensing by charged black holes in scalar-tensor gravity
Energy Technology Data Exchange (ETDEWEB)
Eiroa, Ernesto F.; Sendra, Carlos M. [Instituto de Astronomia y Fisica del Espacio (IAFE, CONICET-UBA), Buenos Aires (Argentina); Universidad de Buenos Aires, Departamento de Fisica, Facultad de Ciencias Exactas y Naturales, Buenos Aires (Argentina)
2014-11-15
We examine a class of charged black holes in scalar-tensor gravity as gravitational lenses. We find the deflection angle in the strong deflection limit, from which we obtain the positions and the magnifications of the relativistic images. We compare our results with those corresponding to the Reissner-Norstroem spacetime and we analyze the observational aspects in the case of the Galactic supermassive black hole. (orig.)
On Hawking Radiation from a Charged Black Hole of Heterotic String Theory
International Nuclear Information System (INIS)
We investigate the Hawking radiation of a GMGHS charged black hole from the heterotic string scenario by the massive particles tunneling method. We consider the spacetime background to be dynamical, incorporate the self-gravitation effect of the emitted particles and show that the tunneling rate is related to the change of Bekenstein–Hawking entropy and the derived emission spectrum does not deviate from the pure thermal spectrum of Schwrzschild's black hole
Comment on geometrothermodynamics of a charged black hole of string theory
International Nuclear Information System (INIS)
We comment on the conclusions found by Larranaga and Mojica (Braz J Phys 41:154, 2011) regarding the consistency of the geometrothermodynamics programme to describe the critical behaviour of a Gibbons-Maeda-Garfinkle-Horowitz-Strominger charged black hole. We argue that making the appropriate choice of metric for the thermodynamic phase space and, most importantly, considering the homogeneity of the thermodynamic potential we obtain consistent results for such a black hole. (author)
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.
Hawking Radiation of Warped Anti de Sitter and Rotating Hairy Black Holes with Scalar Hair
Gursel, H
2015-01-01
This thesis mainly focuses on the Hawking radiation (HR) evacuating from the surface of the objects that have earned a reputation as the most extraordinary objects existing so far; the black holes (BHs). Throughout this study, quantum tunneling (QT) process serves as the model for the HR of scalar, vector and Dirac particles. The scalar and Dirac particles are anticipated to be tunneling through the horizon of rotating scalar hairy black holes (RHSBHs); whilst the vector particles are associated with a rotating warped anti de-Sitter black hole (WAdS3BH) embedded in a (2+1) dimensional fabric. It is no coincidence that for all three cases; the standard HT expression is derived. Additionally, the engagement of conformal field theory (CFT) with anti de-Sitter (AdS) space presents itself to the reader and the methodologies of Klein-Gordon equation (KGE), Dirac equation and Proca equations (PEs) are introduced. For all three cases, Hamilton-Jacobi (HJ) approach is used, together with Wentzel-Kramers-Brillouin (WKB...
Three-dimensional charged Einstein-aether black holes and Smarr formula
Ding, Chikun; Wang, Anzhong; Jing, Jiliang
2016-01-01
We investigate the three-dimensional behavior of gravity coupled to a dynamical unit timelike vector: the aether, and present two new classes of exact charged solutions. When c_{13}=0,\\Lambda'=0$, we find the solutions is the usual BTZ black hole but now with an universal horizon. In the frame of black hole chemistry, we then calculate the temperature of the universal horizons and, construct the Smarr formulas and first law in the three cases: quasi-asymptotically flat, aether asymptotically flat and quasi-BTZ black hole spacetime. We found these universal horizons obey an exact (or slightly modified) first law of black hole mechanics and may have an entropy and, black hole mass can be interpreted as enthalpy of spacetime. Then the holography may be extended to these horizons under violating Lorentz symmetry.
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.
The Nernst theorem and statistical entropy in a (1+1)-dimensional charged black hole
International Nuclear Information System (INIS)
It was derived that the bosonic and fermionic entropies in (1+1)-dimensional charged black hole directly by using the quantum statistical method. The result is the same as the integral expression obtained by solving the wave equation approximately. Then it is obtained the statistical entropy of the black hole by integration via the improved brick-wall method, membrane model. The derived entropy satisfies the thermodynamic relation. When the radiation temperature of the black hole tends to zero, so does the entropy. It obeys Nernst theorem. So it can be taken as Planck absolute entropy
Effects of dark energy on P-V criticality of charged AdS black holes
Li, Gu-Qiang
2014-01-01
In this Letter, we investigate the effects of dark energy on $P-V$ criticality of charged AdS black holes by considering the case of the RN-AdS black holes surrounded by quintessence. By treating the cosmological constant as thermodynamic pressure, we study its thermodynamics in the extended phase space. It is shown that quintessence dark energy does not affect the existence of small/large black hole phase transition. For the case $\\omega_q=-2/3$ we derive analytic expressions of critical phy...
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.
Three-dimensional SCFT on conic space as hologram of charged topological black hole
International Nuclear Information System (INIS)
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
Non-commutative geometry inspired higher-dimensional charged black holes
International Nuclear Information System (INIS)
We obtain a new, exact, solution of the Einstein's equation in higher dimensions. The source is given by a static spherically symmetric, Gaussian distribution of mass and charge. The resulting metric describes a regular, i.e. curvature singularity free, charged black hole in higher dimensions. The metric smoothly interpolates between Reissner-Nordstroem geometry at large distance, and de Sitter spacetime at short distance. Thermodynamical properties of the black hole are investigated and the form of the Area Law is determined. We study pair creation and show that the upper bound on the discharge time increases with the number of extra dimensions
Tunneling of massive and charged particles from noncommutative Reissner-Nordström black hole
Nozari, Kourosh; Islamzadeh, Sara
2013-10-01
Massive charged and uncharged particles tunneling from commutative Reissner-Nordström 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-Nordström 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.
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.
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.
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.