Artykuły w czasopismach: „Einstein-Maxwell-Scalar system”

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Koh, I. G., Y. S. Myung i H. Nishino. "Stability analysis of Einstein/Maxwell-scalar system". Physical Review D 32, nr 12 (15.12.1985): 3195–200. http://dx.doi.org/10.1103/physrevd.32.3195.

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Jantzen, Robert T. "Finite-dimensional Einstein-Maxwell-scalar field system". Physical Review D 33, nr 8 (15.04.1986): 2121–35. http://dx.doi.org/10.1103/physrevd.33.2121.

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Tadmon, Calvin, i Sophonie Blaise Tchapnda. "On the spherically symmetric Einstein–Yang–Mills–Higgs equations in Bondi coordinates". Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences 468, nr 2146 (15.06.2012): 3191–214. http://dx.doi.org/10.1098/rspa.2012.0171.

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We revisit and generalize, to the Einstein–Yang–Mills–Higgs (EYMH) system, previous results of Christodoulou and Chae concerning global solutions for the Einstein-scalar field and the Einstein–Maxwell–Higgs (EMH) equations. The novelty of the present work is twofold. For one thing, the assumption on the self-interaction potential is improved. For another thing, explanation is furnished why the solutions obtained here and those proved by Chae for the EMH system decay more slowly than those established by Christodoulou in the case of self-gravitating scalar fields. Actually, this latter phenomenon stems from the non-vanishing local charge in EMH and EYMH models.

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Fabris, Júlio C., Tales Augusto Oliveira Gomes i Denis Campos Rodrigues. "Black Hole and Wormhole Solutions in Einstein–Maxwell Scalar Theory". Universe 8, nr 3 (27.02.2022): 151. http://dx.doi.org/10.3390/universe8030151.

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We classified and studied the charged black hole and wormhole solutions in the Einstein–Maxwell system in the presence of a massless, real scalar field. The possible existence of charged black holes in general scalar–tensor theories was studied in Bronnikov et al., 1999; black holes and wormholes exist for a negative kinetic term for the scalar field. Using a conformal transformation, the static, spherically symmetric possible structures in the minimal coupled system are described. Besides wormholes and naked singularities, only a restricted class of black hole exists, exhibiting a horizon with an infinite surface and a timelike central singularity. The black holes and wormholes defined in the Einstein frame have some specificities with respect to the non-minimal coupling original frame, which are discussed in the text.

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Nurmagambetov, A. J., i I. Y. Park. "Quantum-Gravitational Trans-Planckian Energy of a Time-Dependent Black Hole". Symmetry 11, nr 10 (16.10.2019): 1303. http://dx.doi.org/10.3390/sym11101303.

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We continue our recent endeavor in which a time-dependent black hole solution of a one-loop quantum-corrected Einstein-scalar system was obtained and its near-horizon behavior was analyzed. The energy analysis led to a trans-Planckian scaling behavior near the event horizon. In the present work, the analysis is extended to a rotating black hole solution of an Einstein–Maxwell-scalar system with a Higgs potential. Although the analysis becomes much more complex compared to that of the previous, we observe the same basic features, including the quantum-gravitational trans-Planckian energy near the horizon.

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Norbert, Noutchegueme. "GLOBAL REGULAR SOLUTION FOR THE EINSTEIN-MAXWELL-BOLTZMANN-SCALAR FIELD SYSTEM IN A BIANCHI TYPE-I SPACE-TIME". JOURNAL OF ADVANCES IN MATHEMATICS 13, nr 1 (30.03.2017): 7087–118. http://dx.doi.org/10.24297/jam.v13i1.5982.

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We prove an existence and uniqueness of regular solution to the Einstein-Maxwell-Boltzmann-Scalar Field system with pseudo-tensor of pressure and the cosmological constant globaly in time. We clarify the choice of the function spaces and we establish step by step all the essential energy estimations leading to the global existence theorem.

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Panotopoulos, Grigoris, i Ángel Rincón. "Charged slowly rotating toroidal black holes in the (1 + 3)-dimensional Einstein-power-Maxwell theory". International Journal of Modern Physics D 28, nr 01 (styczeń 2019): 1950016. http://dx.doi.org/10.1142/s0218271819500160.

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In this work, we find charged slowly rotating solutions in the four-dimensional Einstein-power-Maxwell nonlinear electrodynamics assuming a negative cosmological constant. By solving the system of coupled field equations explicitly, we obtain an approximate analytical solution in the small rotation limit. The solution obtained is characterized by a flat horizon structure, and it corresponds to a toroidal black hole. The Smarr’s formula, the thermodynamics and the invariants Ricci scalar and Kretschmann scalar are briefly discussed.

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Lazaroiu, C. I., i C. S. Shahbazi. "Generalized Einstein-Scalar-Maxwell theories and locally geometric U-folds". Reviews in Mathematical Physics 30, nr 05 (31.05.2018): 1850012. http://dx.doi.org/10.1142/s0129055x18500125.

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We give the global mathematical formulation of the coupling of four-dimensional scalar sigma models to Abelian gauge fields on a Lorentzian four-manifold, for the generalized situation when the duality structure of the Abelian gauge theory is described by a flat symplectic vector bundle [Formula: see text] defined over the scalar manifold [Formula: see text]. The construction uses a taming of [Formula: see text], which we find to be the correct mathematical object globally encoding the inverse gauge couplings and theta angles of the “twisted” Abelian gauge theory in a manner that makes no use of duality frames. We show that global solutions of the equations of motion of such models give classical locally geometric U-folds. We also describe the groups of duality transformations and scalar-electromagnetic symmetries arising in such models, which involve lifting isometries of [Formula: see text] to the bundle [Formula: see text] and hence differ from expectations based on local analysis. The appropriate version of the Dirac quantization condition involves a discrete local system defined over [Formula: see text] and gives rise to a smooth bundle of polarized Abelian varieties, endowed with a flat symplectic connection. This shows, in particular, that a generalization of part of the mathematical structure familiar from [Formula: see text] supergravity is already present in such purely bosonic models, without any coupling to fermions and hence without any supersymmetry.

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Mazharimousavi, S. Habib, i M. Halilsoy. "Einstein–Born–Infeld black holes with a scalar hair in three dimensions". Modern Physics Letters A 30, nr 33 (13.10.2015): 1550177. http://dx.doi.org/10.1142/s0217732315501771.

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We present black hole solutions in (2+1)-dimensional Einstein’s theory of gravity coupled with Born–Infeld (BI) nonlinear electrodynamic and a massless self-interacting scalar field. The model has five free parameters: mass [Formula: see text], cosmological constant [Formula: see text], electric [Formula: see text] and scalar [Formula: see text] charges and BI parameter [Formula: see text]. To attain exact solution for such a highly nonlinear system we adjust, i.e. finely tune, the parameters of the theory with the integration constants. In the limit [Formula: see text], we recover the results of Einstein–Maxwell–Scalar theory, obtained before. The self-interacting potential admits finite minima apt for the vacuum contribution. Hawking temperature of the model is investigated versus properly tuned parameters. By employing this tuned-solution as basis, we obtain also a dynamic solution which in the proper limit admits the known solution in Einstein gravity coupled with self-interacting scalar field. Finally, we establish the equations of a general scalar–tensor field coupled to nonlinear electrodynamics (NED) field in 2+1 dimensions without searching for exact solutions.

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Jaramillo, Víctor, Daniel Martínez-Carbajal, Juan Carlos Degollado i Darío Núñez. "Born-Infeld boson stars". Journal of Cosmology and Astroparticle Physics 2023, nr 07 (1.07.2023): 017. http://dx.doi.org/10.1088/1475-7516/2023/07/017.

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Abstract We study the Einstein-Klein-Gordon system coupled to the Born-Infeld electrodynamics. We explore the solution space of a static spherically symmetric, complex scalar field minimally coupled to both gravitational and electromagnetic fields. The resulting asymptotically flat solutions resemble the known charged boson stars in Maxwell electrodynamics. The behaviour of such configurations as a function of the Born-Infeld parameter b and the scalar field charge parameter q has been analyzed. Given b, a critical value for q exists beyond which no static solutions exist, we find that the value of this critical charge increases with respect to the Maxwell case (b → ∞) as b decreases. We also found that Born-Infeld boson stars have lower mass for any finite value of the Born-Infeld parameter and that their compactness is lower than Maxwell's counterparts.

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Costa, João L., Pedro M. Girão, José Natário i Jorge Drumond Silva. "On the Global Uniqueness for the Einstein–Maxwell-Scalar Field System with a Cosmological Constant". Communications in Mathematical Physics 339, nr 3 (2.08.2015): 903–47. http://dx.doi.org/10.1007/s00220-015-2433-6.

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LACQUANITI, V., i G. MONTANI. "GEOMETRY AND MATTER REDUCTION IN A 5D KALUZA–KLEIN FRAMEWORK". Modern Physics Letters A 24, nr 20 (28.06.2009): 1565–75. http://dx.doi.org/10.1142/s0217732309030904.

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In this paper we consider the Kaluza–Klein field equations in the presence of a generic 5D matter tensor which is governed by a conservation equation due to 5D Bianchi identities. Following a previous work, we provide a consistent approach to matter where the problem of huge massive modes is removed, without relaxing the compactification hypotheses; therefore we perform the dimensional reduction either for metric fields and for matter, thus identifying a pure 4D tensor term, a 4D vector term and a scalar one. Hence we are able to write down a consistent set of equations for the complete dynamics of matter and fields; with respect to the pure Einstein–Maxwell system we now have two additional scalar fields: the usual dilaton one plus a scalar source term. Some significant scenarios involving these terms are discussed and perspectives for cosmological applications are suggested.

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DARIESCU, CIPRIAN, i MARINA–AURA DARIESCU. "TRANSITION AND REGENERATION RATES IN CHARGED BOSON STARS VIA PERTURBATIVE CALCULATIONS". International Journal of Modern Physics A 20, nr 11 (30.04.2005): 2326–30. http://dx.doi.org/10.1142/s0217751x05024572.

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In a SO(3,1)×U(1) framework, we analytically derive the first-order approximating solutions to the system of Klein–Gordon–Maxwell–Einstein equations describing a minimally coupled charged boson field to a spherically symmetric spacetime. Within a perturbative approach, we analyze the feedback of gravity and electric field on the charged scalar source and we get the coherent source-field regeneration rate. It turns out that we are dealing with an extremely short time-constant which is confirming the other authors' conclusion that intense gravitational bursts are accompanying the boson star formation.

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BRONNIKOV, K. A. "EXTRA DIMENSIONS AND POSSIBLE SPACE-TIME SIGNATURE CHANGES". International Journal of Modern Physics D 04, nr 04 (sierpień 1995): 491–516. http://dx.doi.org/10.1142/s0218271895000351.

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Exact static, spherically symmetric solutions to the Einstein-Maxwell-scalar equations, with a dilatonic-type scalar-vector coupling, in D-dimensional gravity with a chain of n Ricci-flat internal spaces are considered, with the Maxwell field potential having two nonzero components: the temporal, Coulomb-like one and the one pointing to one of the extra dimensions. The properties and special cases of the solutions are discussed, in particular, those when there are horizons in the space-time. Two types of horizons are distinguished: the conventional black-hole (BH) ones and those at which the physical section of the space-time changes its signature (the latter are called T-horizons). Two theorems are proved, one fixing the BH- and T-horizon existence conditions, the other claiming that the system under study cannot have a regular center. The stability of a selected family of solutions under spherically symmetric perturbations is studied. It is shown that only black-hole solutions are stable, while all others, in particular, those with T-horizons are unstable.

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Maeda, Hideki, i Cristián Martínez. "Higher-dimensional Buchdahl and Janis–Robinson–Winicour transformations in the Einstein–Maxwell system with a massless scalar field". Classical and Quantum Gravity 36, nr 18 (28.08.2019): 185017. http://dx.doi.org/10.1088/1361-6382/ab293a.

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Noutchegueme, Norbert, i Alexis Nangue. "Global existence of solutions to the Einstein–Maxwell–Massive scalar field system in 3 + 1 formulation on Bianchi spacetimes". Applicable Analysis 93, nr 5 (7.10.2013): 1036–56. http://dx.doi.org/10.1080/00036811.2013.816684.

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Hendi, S. H., S. Panahiyan i B. Eslam Panah. "P–V criticality and geometrical thermodynamics of black holes with Born–Infeld type nonlinear electrodynamics". International Journal of Modern Physics D 25, nr 01 (styczeń 2016): 1650010. http://dx.doi.org/10.1142/s0218271816500103.

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In this paper, we take into account the black-hole solutions of Einstein gravity in the presence of logarithmic and exponential forms of nonlinear electrodynamics. At first, we consider the cosmological constant as a dynamical pressure to study the phase transitions and analogy of the black holes with the Van der Waals liquid–gas system in the extended phase space. We make a comparison between linear and nonlinear electrodynamics and show that the lowest critical temperature belongs to Maxwell theory. Also, we make some arguments regarding how power of nonlinearity brings the system to Schwarzschild-like and Reissner–Nordström-like limitations. Next, we study the critical behavior of the system in the context of heat capacity. We show that critical behavior of system is similar to the one in phase diagrams of extended phase space. We also extend the study of phase transition points through geometrical thermodynamics (GTs). We introduce two new thermodynamical metrics for extended phase space and show that divergencies of thermodynamical Ricci scalar (TRS) of the new metrics coincide with phase transition points of the system. Then, we introduce a new method for obtaining critical pressure and horizon radius by considering denominator of the heat capacity.

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Costa, João L., Pedro M. Girão, José Natário i Jorge Drumond Silva. "On the global uniqueness for the Einstein–Maxwell-scalar field system with a cosmological constant: I. Well posedness and breakdown criterion". Classical and Quantum Gravity 32, nr 1 (8.12.2014): 015017. http://dx.doi.org/10.1088/0264-9381/32/1/015017.

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Costa, João L., Pedro M. Girão, José Natário i Jorge Drumond Silva. "On the Occurrence of Mass Inflation for the Einstein–Maxwell-Scalar Field System with a Cosmological Constant and an Exponential Price Law". Communications in Mathematical Physics 361, nr 1 (26.03.2018): 289–341. http://dx.doi.org/10.1007/s00220-018-3122-z.

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Guendelman, Eduardo, Emil Nissimov i Svetlana Pacheva. "Vacuum structure and gravitational bags produced by metric-independent space–time volume-form dynamics". International Journal of Modern Physics A 30, nr 22 (5.08.2015): 1550133. http://dx.doi.org/10.1142/s0217751x1550133x.

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We propose a new class of gravity-matter theories, describing [Formula: see text] gravity interacting with a nonstandard nonlinear gauge field system and a scalar “dilaton,” formulated in terms of two different non-Riemannian volume-forms (generally covariant integration measure densities) on the underlying space–time manifold, which are independent of the Riemannian metric. The nonlinear gauge field system contains a square-root [Formula: see text] of the standard Maxwell Lagrangian which is known to describe charge confinement in flat space–time. The initial new gravity-matter model is invariant under global Weyl-scale symmetry which undergoes a spontaneous breakdown upon integration of the non-Riemannian volume-form degrees of freedom. In the physical Einstein frame we obtain an effective matter-gauge-field Lagrangian of “k-essence” type with quadratic dependence on the scalar “dilaton” field kinetic term [Formula: see text], with a remarkable effective scalar potential possessing two infinitely large flat regions as well as with nontrivial effective gauge coupling constants running with the “dilaton” [Formula: see text]. Corresponding to each of the two flat regions we find “vacuum” configurations of the following types: (i) [Formula: see text] and a nonzero gauge field vacuum [Formula: see text], which corresponds to a charge confining phase; (ii) [Formula: see text] (“kinetic vacuum”) and ordinary gauge field vacuum [Formula: see text] which supports confinement-free charge dynamics. In one of the flat regions of the effective scalar potential we also find: (iii) [Formula: see text] (“kinetic vacuum”) and a nonzero gauge field vacuum [Formula: see text], which again corresponds to a charge confining phase. In all three cases, the space–time metric is de Sitter or Schwarzschild–de Sitter. Both “kinetic vacuums” (ii) and (iii) can exist only within a finite-volume space region below a de Sitter horizon. Extension to the whole space requires matching the latter with the exterior region with a nonstandard Reissner–Nordström–de Sitter geometry carrying an additional constant radial background electric field. As a result, we obtain two classes of gravitational bag-like configurations with properties, which on one hand partially parallel some of the properties of the solitonic “constituent quark” model and, on the other hand, partially mimic some of the properties of MIT bags in QCD phenomenology.

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Esposito, Giampiero. "A parametrix for quantum gravity?" International Journal of Geometric Methods in Modern Physics 13, nr 05 (21.04.2016): 1650060. http://dx.doi.org/10.1142/s0219887816500602.

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In the 60s, DeWitt discovered that the advanced and retarded Green functions of the wave operator on metric perturbations in the de Donder gauge make it possible to define classical Poisson brackets on the space of functionals that are invariant under the action of the full diffeomorphism group of spacetime. He therefore tried to exploit this property to define invariant commutators for the quantized gravitational field, but the operator counterpart of such classical Poisson brackets turned out to be a hard task. On the other hand, in the mathematical literature, it is by now clear that, rather than inverting exactly an hyperbolic (or elliptic) operator, it is more convenient to build a quasi-inverse, i.e. an inverse operator up to an operator of lower order which plays the role of regularizing operator. This approximate inverse, the parametrix, which is, strictly, a distribution, makes it possible to solve inhomogeneous hyperbolic (or elliptic) equations. We here suggest that such a construction might be exploited in canonical quantum gravity provided one understands what is the counterpart of classical smoothing operators in the quantization procedure. We begin with the simplest case, i.e. fundamental solution and parametrix for the linear, scalar wave operator; the next step are tensor wave equations, again for linear theory, e.g. Maxwell theory in curved spacetime. Last, the nonlinear Einstein equations are studied, relying upon the well-established Choquet-Bruhat construction, according to which the fifth derivatives of solutions of a nonlinear hyperbolic system solve a linear hyperbolic system. The latter is solved by means of Kirchhoff-type formulas, while the former fifth-order equations can be solved by means of well-established parametrix techniques for elliptic operators. But then the metric components that solve the vacuum Einstein equations can be obtained by convolution of such a parametrix with Kirchhoff-type formulas. Some basic functional equations for the parametrix are also obtained, that help in studying classical and quantum version of the Jacobi identity.

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Khilji, Mohd Javed. "Modified transformation laws of coordinates and composition of velocities". International Journal of Advanced Astronomy 5, nr 1 (2.04.2017): 61. http://dx.doi.org/10.14419/ijaa.v5i1.7385.

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A new transformation law of coordinates is determined, which allows the inclusion of complex velocity vectors. It is found that in an isotropic universe which is filled with matter throughout, each frame can have references for its position of rest or of motion in a localized domain wherein a frame at rest does not change its position with time relative to surroundings. However, in the system, the moving frame sees only a reflection of its own motion in the rest-frame to appear it moving in antipodal direction. It is therefore, the relative motion cannot be said to be a just direction reversal with two real velocities having a single magnitude common between them; however, it is a synthesis of both real and imaginary motions. The proposed transformation laws are similar to that of Lorentz under which vector quantities be in cross product or in dot product remain invariant such as Maxwell equations. However, inherent scalar quantities such as mass, time etc. vary to distinguish rest-frame from the moving one. It is seen that the physical processes are exactly the same as Einstein predicted but without reciprocity effects and thus provide a justification of quantization of red-shift and particle decay. These considerations are useful in understanding the intricacies of the micro world such as short-lived particle, antimatter, subatomic particles, gamma rays, gamma-ray burst (GRBs), cosmic rays, dark matter, and asymmetry of Doppler’s shifting images.

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Frønsdal, Christian. "Relativistic thermodynamics, a Lagrangian field theory for general flows including rotation". International Journal of Geometric Methods in Modern Physics 14, nr 02 (18.01.2017): 1750017. http://dx.doi.org/10.1142/s0219887817500177.

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Any theory that is based on an action principle has a much greater predictive power than one that does not have such a formulation. The formulation of a dynamical theory of General Relativity, including matter, is here viewed as a problem of coupling Einstein’s theory of pure gravity to an independently chosen and well-defined field theory of matter. It is well known that this is accomplished in a most natural way when both theories are formulated as relativistic, Lagrangian field theories, as is the case with Einstein–Maxwell theory. Special matter models of this type have been available; here a more general thermodynamical model that allows for vortex flows is presented. In a wider context, the problem of subjecting hydrodynamics and thermodynamics to an action principle is one that has been pursued for at least 150 years. A solution to this problem has been known for some time, but only under the strong restriction to potential flows. A variational principle for general flows has become available. It represents a development of the Navier–Stokes–Fourier approach to fluid dynamics. The principal innovation is the recognition that two kinds of flow velocity fields are needed, one the gradient of a scalar field and the other the time derivative of a vector field, the latter closely associated with vorticity. In the relativistic theory that is presented here, the latter is the Hodge dual of an exact 3-form, well known as the notoph field of Ogievetskij and Palubarinov, the [Formula: see text]-field of Kalb and Ramond and the vorticity field of Lund and Regge. The total number of degrees of freedom of a unary system, including the density and the two velocity fields is 4, as expected — as in classical hydrodynamics. In this paper, we do not reduce Einstein’s dynamical equation for the metric to phenomenology, which would have denied the relevance of any intrinsic dynamics for the matter sector, nor do we abandon the equation of continuity - the very soul of hydrodynamics.

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Dehghani, M. H., i A. Khodam-Mohammadi. "Hairy rotating black string in the EinsteinMaxwellHiggs system". Canadian Journal of Physics 83, nr 3 (1.03.2005): 229–42. http://dx.doi.org/10.1139/p04-083.

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We show numerically that the Abelian Higgs-field equations in the background of a four-dimensional rotating charged black string have vortex solutions. These solutions, which have axial symmetry, establish that the rotating black string can support the Abelian Higgs field as hair. We find an electric field coupled to the Higgs scalar field in the case of a rotating black string. This electric field is due to an electric charge-per-unit-length, which increases as the rotation parameter increases. We also find that the vortex thickness decreases as the rotation parameter increases. Finally, we consider the self-gravity of the Abelian Higgs field and show that the effect of the vortex is to induce a deficit angle in the metric under consideration, which decreases as the rotation parameter increases. PACS Nos.: 04.70.s, 04.40.b, 11.27.+d

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Park, I. Y. "Quantization of Gravity and Finite Temperature Effects". Particles 4, nr 4 (14.10.2021): 468–88. http://dx.doi.org/10.3390/particles4040035.

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Gravity is perturbatively renormalizable for the physical states which can be conveniently defined via foliation-based quantization. In recent sequels, one-loop analysis was explicitly carried out for Einstein-scalar and Einstein-Maxwell systems. Various germane issues and all-loop renormalizability have been addressed. In the present work we make further progress by carrying out several additional tasks. Firstly, we present an alternative 4D-covariant derivation of the physical state condition by examining gauge choice-independence of a scattering amplitude. To this end, a careful dichotomy between the ordinary, and large gauge symmetries is required and appropriate gauge-fixing of the ordinary symmetry must be performed. Secondly, vacuum energy is analyzed in a finite-temperature setup. A variant optimal perturbation theory is implemented to two-loop. The renormalized mass determined by the optimal perturbation theory turns out to be on the order of the temperature, allowing one to avoid the cosmological constant problem. The third task that we take up is examination of the possibility of asymptotic freedom in finite-temperature quantum electrodynamics. In spite of the debates in the literature, the idea remains reasonable.

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Tucker, R. W., i T. J. Walton. "Scalar Pre-potentials for Spinor and Tensor Fields on Spacetime". Journal of Physics: Conference Series 2191, nr 1 (1.02.2022): 012020. http://dx.doi.org/10.1088/1742-6596/2191/1/012020.

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Abstract We review a technique for solving a class of classical linear partial diferential systems of relevance to physics in Minkowski spacetime. All the equations are amenable to analysis in terms of complex solutions in the kernel of the scalar Laplacian and a complexifed Hertz potential. The complexifcation prescription ensures the existence of regular physical solutions with chirality and propagating, non-singular, pulse-like characteristics that are bounded in all three spatial dimensions. The technique is applied to the source-free Maxwell, Bopp-Landé-Podolsky and linearised Einstein feld systems, and particular solutions are used for constructing classical models describing single-cycle laser pulses and a mechanism is discussed for initiating astrophysical jets. Our article concludes with a brief introduction to spacetime Cliford algebra ideals that we use to represent spinor felds. We employ these to demonstrate how the same technique used for tensor felds enables one to construct new propagating, chiral, non-singular, pulse-like spinor solutions to the massless Dirac equation in Minkowski spacetime.

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Alba, David, i Luca Lusanna. "The Einstein–Maxwell-particle system in the York canonical basis of ADM tetrad gravity. Part 3. The post-minkowskian N-body problem, its post-newtonian limit in nonharmonic 3-orthogonal gauges and dark matter as an inertial effect 1This paper is one of three companion papers published in the same issue of Can. J. Phys." Canadian Journal of Physics 90, nr 11 (listopad 2012): 1131–78. http://dx.doi.org/10.1139/p11-102.

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We conclude the study of the post-minkowskian (PM) linearization of ADM tetrad gravity in the York canonical basis for asymptotically minkowskian space–times in the family of nonharmonic 3-orthogonal gauges parametrized by the York time 3K(τ, s) (the inertial gauge variable, not existing in Newton gravity, describing the general relativistic remnant of the freedom in clock synchronization in the definition of the shape of the instantaneous 3-spaces as 3-submanifolds of space–time). As matter we consider only N scalar point particles with a Grassmann regularization of the self-energies and with an ultraviolet cutoff making possible the PM linearization and the evaluation of the PM solution for the gravitational field. We study in detail all the properties of these PM space–times emphasizing their dependence on the gauge variable 3K(1) = (1/Δ)3K(1) (the nonlocal York time): Riemann and Weyl tensors, 3-spaces, time-like and null geodesics, red-shift, and luminosity distance. Then we study the post-newtonian (PN) expansion of the PM equations of motion of the particles. We find that in the two-body case at the 0.5PN order there is a damping (or antidamping) term depending only on 3K(1). This opens the possibility of explaining dark matter in Einstein theory as a relativistic inertial effect: the determination of 3K(1) from the masses and rotation curves of galaxies would give information on how to find a PM extension of the existing PN celestial frame used as an observational convention in the 4-dimensional description of stars and galaxies. Dark matter would describe the difference between the inertial and gravitational masses seen in the non-euclidean 3-spaces, without a violation of their equality in the 4-dimensional space–time as required by the equivalence principle.

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Alba, David, i Luca Lusanna. "The Einstein–Maxwell-particle system in the York canonical basis of ADM tetrad gravity. Part 1. The equations of motion in arbitrary Schwinger time gauges 1This paper is one of three companion papers published in the same issue of Can. J. Phys." Canadian Journal of Physics 90, nr 11 (listopad 2012): 1017–76. http://dx.doi.org/10.1139/p11-100.

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We study the coupling of N charged scalar particles plus the electromagnetic field to Arnowitt–Deser–Misner (ADM) tetrad gravity and its canonical formulation in asymptotically Minkowskian space–times without super-translations. To regularize the self-energies, both the electric charge and the sign of the energy of the particles are Grassmann-valued. The introduction of the noncovariant radiation gauge allows reformulation of the theory in terms of transverse electromagnetic fields and to extract the generalization of the Coulomb interaction among the particles in the riemannian instantaneous 3-spaces of global noninertial frames, the only ones allowed by the equivalence principle. Then we make the canonical transformation to the York canonical basis, where there is a separation between the inertial (gauge) variables and the tidal ones inside the gravitational field and a special role of the eulerian observers associated with the 3+1 splitting of space–time. The Dirac hamiltonian is weakly equal to the weak ADM energy. The Hamilton equations in Schwinger time gauges are given explicitly. In the York basis they are naturally divided into four sets: (i) the contracted Bianchi identities; (ii) the equations for the inertial gauge variables; (iii) the equations for the tidal ones; and (iv) the equations for matter. Finally, we give the restriction of the Hamilton equations and of the constraints to the family of nonharmonic 3-orthogonal gauges, in which the instantaneous riemannian 3-spaces have a nonfixed trace 3K of the extrinsic curvature but a diagonal 3-metric. The inertial gauge variable 3K (the general-relativistic remnant of the freedom in the clock synchronization convention) gives rise to a negative kinetic term in the weak ADM energy vanishing only in the gauges with 3K = 0: is it relevant for dark energy and back-reaction? In the second paper will appear the linearization of the theory in these nonharmonic 3-orthogonal gauges to obtain hamiltonian post-minkowskian gravity (without post-newtonian approximations) with asymptotic Minkowski background, nonflat instantaneous 3-spaces and no post-newtonian expansion. This will allow the exploration of the inertial effects induced by the York time 3K in nonflat 3-spaces (they do not exist in newtonian gravity) and to check how well dark matter can be explained as an inertial aspect of Einstein’s general relativity: this will be done in a third paper on the post-minkowskian 2-body problem in the absence of the electromagnetic field and on its 0.5 post-newtonian limit.

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29

Svedberg, Christopher. "Future Stability of the Einstein-Maxwell-Scalar Field System". Annales Henri Poincaré 12, nr 5 (29.03.2011). http://dx.doi.org/10.1007/s00023-011-0099-y.

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30

Xiong, Wei, Peng Liu, Chao Niu, Cheng-Yong Zhang i bin 王斌 wang. "Dynamical spontaneous scalarization in Einstein-Maxwell-scalar theory". Chinese Physics C, 18.05.2022. http://dx.doi.org/10.1088/1674-1137/ac70ad.

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Abstract We study the linear instability and the nonlinear dynamical evolution of the Reissner-Nordstr\"om (RN) black hole in the Einstein-Maxwell-scalar theory in asymptotic flat spacetime. We focus on the coupling function $f(\phi)=e^{-b\phi^2}$ which allows both the scalar-free RN solution and scalarized black hole solution. We first present the evolution of system parameters during dynamic scalarization. For parameter regions where spontaneous scalarization occurs, we find that the evolution of the scalar field at the horizon is dominated by the fundamental unstable mode from linear analysis at early times. At late times, the nonlinear evolution can be viewed as the perturbation of scalarized black holes.

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31

Guo, Guangzhou, Peng Wang, Houwen Wu i Haitang Yang. "Scalarized Einstein–Maxwell-scalar black holes in anti-de Sitter spacetime". European Physical Journal C 81, nr 10 (październik 2021). http://dx.doi.org/10.1140/epjc/s10052-021-09614-7.

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AbstractIn this paper, we study spontaneous scalarization of asymptotically anti-de Sitter charged black holes in an Einstein–Maxwell-scalar model with a non-minimal coupling between the scalar and Maxwell fields. In this model, Reissner–Nordström-AdS (RNAdS) black holes are scalar-free black hole solutions, and may induce scalarized black holes due to the presence of a tachyonic instability of the scalar field near the event horizon. For RNAdS and scalarized black hole solutions, we investigate the domain of existence, perturbative stability against spherical perturbations and phase structure. In a micro-canonical ensemble, scalarized solutions are always thermodynamically preferred over RNAdS black holes. However, the system has much richer phase structure and phase transitions in a canonical ensemble. In particular, we report a RNAdS BH/scalarized BH/RNAdS BH reentrant phase transition, which is composed of a zeroth-order phase transition and a second-order one.

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32

Guo, Guangzhou, Peng Wang, Houwen Wu i Haitang Yang. "Scalarized Einstein–Maxwell-scalar black holes in anti-de Sitter spacetime". European Physical Journal C 81, nr 10 (październik 2021). http://dx.doi.org/10.1140/epjc/s10052-021-09614-7.

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AbstractIn this paper, we study spontaneous scalarization of asymptotically anti-de Sitter charged black holes in an Einstein–Maxwell-scalar model with a non-minimal coupling between the scalar and Maxwell fields. In this model, Reissner–Nordström-AdS (RNAdS) black holes are scalar-free black hole solutions, and may induce scalarized black holes due to the presence of a tachyonic instability of the scalar field near the event horizon. For RNAdS and scalarized black hole solutions, we investigate the domain of existence, perturbative stability against spherical perturbations and phase structure. In a micro-canonical ensemble, scalarized solutions are always thermodynamically preferred over RNAdS black holes. However, the system has much richer phase structure and phase transitions in a canonical ensemble. In particular, we report a RNAdS BH/scalarized BH/RNAdS BH reentrant phase transition, which is composed of a zeroth-order phase transition and a second-order one.

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33

Hod, Shahar. "Charged Gauss–Bonnet black holes supporting non-minimally coupled scalar clouds: analytic treatment in the near-critical regime". European Physical Journal C 83, nr 3 (15.03.2023). http://dx.doi.org/10.1140/epjc/s10052-023-11385-2.

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AbstractRecent numerical studies have revealed the physically intriguing fact that charged black holes whose charge-to-mass ratios are larger than the critical value $$(Q/M)_{\text {crit}}=\sqrt{2(9+\sqrt{6})}/5$$ ( Q / M ) crit = 2 ( 9 + 6 ) / 5 can support hairy matter configurations which are made of scalar fields with a non-minimal negative coupling to the Gauss–Bonnet invariant of the curved spacetime. Using analytical techniques, we explore the physical and mathematical properties of the composed charged-black-hole-nonminimally-coupled-linearized-massless-scalar-field configurations in the near-critical $$Q/M\gtrsim (Q/M)_{\text {crit}}$$ Q / M ≳ ( Q / M ) crit regime. In particular, we derive an analytical resonance formula that describes the charge-dependence of the dimensionless coupling parameter $$\bar{\eta }_{\text {crit}}=\bar{\eta }_{\text {crit}}(Q/M)$$ η ¯ crit = η ¯ crit ( Q / M ) of the composed Einstein–Maxwell-nonminimally-coupled-scalar-field system along the existence-line of the theory, a critical border that separates bald Reissner–Nordström black holes from hairy charged-black-hole-scalar-field configurations. In addition, it is explicitly shown that the large-coupling $$-\bar{\eta }_{\text {crit}}(Q/M)\gg 1$$ - η ¯ crit ( Q / M ) ≫ 1 analytical results derived in the present paper for the composed Einstein–Maxwell-scalar theory agree remarkably well with direct numerical computations of the corresponding black-hole-field resonance spectrum.

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34

Davey, Alex, Oscar J. C. Dias i Paul Rodgers. "Phase diagram of the charged black hole bomb system". Journal of High Energy Physics 2021, nr 5 (maj 2021). http://dx.doi.org/10.1007/jhep05(2021)189.

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Abstract We find the phase diagram of solutions of the charged black hole bomb system. In particular, we find the static hairy black holes of Einstein-Maxwell-Scalar theory confined in a Minkowski box. We impose boundary conditions such that the scalar field vanishes at and outside a cavity of constant radius. These hairy black holes are asymptotically flat with a scalar condensate floating above the horizon. We identify four critical scalar charges which mark significant changes in the qualitative features of the phase diagram. When they coexist, hairy black holes always have higher entropy than the Reissner-Nordström black hole with the same quasilocal mass and charge. So hairy black holes are natural candidates for the endpoint of the superradiant/near-horizon instabilities of the black hole bomb system. We also relate hairy black holes to the boson stars of the theory. When it has a zero horizon radius limit, the hairy black hole family terminates on the boson star family. Finally, we find the Israel surface tensor of the box required to confine the scalar condensate and that it can obey suitable energy conditions.

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35

Park, I. Y. "Revisit of renormalization of Einstein-Maxwell theory at one-loop". Progress of Theoretical and Experimental Physics, 19.11.2020. http://dx.doi.org/10.1093/ptep/ptaa167.

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Abstract In a series of the recent works based on foliation-based quantization in which renormalizability has been achieved for the physical sector of the theory, we have shown that the use of the standard graviton propagator interferes, due to the presence of the trace mode, with the 4D covariance. A subtlety in the background field method also requires careful handling. This status of the matter motivated us to revisit an Einstein-scalar system in one of the sequels. Continuing the endeavors, we revisit the one-loop renormalization of an Einstein-Maxwell system in the present work. The systematic renormalization of the cosmological and Newton’s constants is carried out by applying the refined background field method. One-loop beta function of the vector coupling constant is explicitly computed and compared with the literature. The longstanding problem of gauge choice-dependence of the effective action is addressed and the manner in which the gauge-choice independence is restored in the present framework is discussed. The formalism also sheds light on background independent analysis. The renormalization involves a metric field redefinition originally introduced by ‘t Hooft; with the field redefinition the theory should be predictive.

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36

An, Xinliang, i Zhan Feng Lim. "Trapped Surface Formation for Spherically Symmetric Einstein–Maxwell-Charged Scalar Field System with Double Null Foliation". Annales Henri Poincaré, 14.03.2022. http://dx.doi.org/10.1007/s00023-022-01168-y.

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37

Torii, Takashi, Kengo Maeda i Makoto Narita. "Black hole no hair conjecture in the Einstein-Maxwell-scalar system in asymptotically de Sitter spacetime". Physical Review D 63, nr 4 (25.01.2001). http://dx.doi.org/10.1103/physrevd.63.047502.

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38

Li, Meng-Wei, Yi Yang i Pei-Hung Yuan. "Analytic study on chiral phase transition in holographic QCD". Journal of High Energy Physics 2021, nr 2 (luty 2021). http://dx.doi.org/10.1007/jhep02(2021)055.

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Abstract The chiral symmetry breaking (χsb) is one of the most fundamental problems in QCD. In this paper, we calculate quark condensation analytically in a holographic QCD model dual to the Einstein-Maxwell-Dilaton (EMD) system coupled to a probe scalar field. We find that the black hole phase transition in the EMD system seriously affects χsb. At small chemical potential, χsb behaves as a crossover. For large chemical potential μ > μc, χsb becomes first order with exactly the same transition temperature as the black hole phase transition by a bypass mechanism. The phase diagram we obtained is qualitatively consistent with the recent results from lattice QCD simulations and NJL models.

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39

Maeda, Hideki, i Cristián Martínez. "All static and electrically charged solutions with Einstein base manifold in the arbitrary-dimensional Einstein–Maxwell system with a massless scalar field". European Physical Journal C 78, nr 10 (październik 2018). http://dx.doi.org/10.1140/epjc/s10052-018-6334-7.

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40

Li, Ran, Jin Wang, Yong-Qiang Wang i Hongbao Zhang. "Nonequilibrium dynamical transition process between excited states of holographic superconductors". Journal of High Energy Physics 2020, nr 11 (listopad 2020). http://dx.doi.org/10.1007/jhep11(2020)059.

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Abstract We study the dynamics of the holographic s-wave superconductors described by the Einstein-Maxwell-complex scalar field theory with a negative cosmological constant. If the eigenfunction of the linearized equation of motion of the scalar field in the planar RNAdS black hole background is chosen as the initial data, the bulk system will evolve to the intermediate state that corresponds to the excited state superconductor on the boundary. The process can be regarded as the non-equilibrium condensation process of the excited state of holographic superconductor. When the linear superposition of the eigenfunctions is chosen as the initial data, the system will go through a series of the intermediate states corresponding to different overtone numbers, which can be regarded as the dynamical transition process between the excited states of holographic superconductor. Because the intermediate states are metastable, the bulk system eventually evolves to the stationary state that corresponds the ground state of the holographic superconductor. We also provide a global and physical picture of the evolution dynamics of the black hole and the corresponding superconducting phase transition from the funneled landscape view, quantifying the weights of the states and characterizing the transitions and cascades towards the ground state.

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41

Costa, João L., Pedro M. Girão, José Natário i Jorge Drumond Silva. "On the Global Uniqueness for the Einstein–Maxwell-Scalar Field System with a Cosmological Constant: Part 3. Mass Inflation and Extendibility of the Solutions". Annals of PDE 3, nr 1 (28.03.2017). http://dx.doi.org/10.1007/s40818-017-0028-6.

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42

Norbert, Noutchegueme, Dongo David i Djiofack Etienne. "Global Properties of the Solution of the Einstein-Maxwell-Boltzmann-Scalar Field System with Pseudo-Tensor of Pressure on a Bianchi Type I Space-Time". General Letters in Mathematics 2, nr 1 (1.01.2017). http://dx.doi.org/10.31559/glm2016.2.1.1.

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43

Phat, Tran Huu, i Toan T. Nguyen. "On the holographic phase transitions at finite topological charge". European Physical Journal C 81, nr 5 (maj 2021). http://dx.doi.org/10.1140/epjc/s10052-021-09141-5.

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AbstractExploring the significant impacts of topological charge on the holographic phase transitions and conductivity we start from an Einstein–Maxwell system coupled with a charged scalar field in Anti-de Sitter spacetime. In our set up, the corresponding black hole (BH) is chosen to be the topological AdS one where the pressure is identified with the cosmological constant (Kubiznak and Mann in JHEP 7:33, 2012), then the AdS BH undergoes the phase transition from small to large BHs, which is totally similar to the transition from gas to liquid in the van der Waals theory. Our numerical computation shows that the process of condensation is favored at finite topological charge, in particular, the phase transition from small to large BHs in the bulk generates a mechanism for changing the order of phase transition in the boundary: the second order phase transitions occur at pressures higher than the critical pressure of the phase transition from small to large BHs while they become first order at lower pressures. This property is confirmed with the aid of holographic free energy. Finally, the frequency dependent conductivity exhibits an energy gap when the phase transition is second order and when the phase transition becomes first order this gap is either reduced or totally lost.

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44

López, José Damián, i Miguel Alcubierre. "Charged boson stars revisited". General Relativity and Gravitation 55, nr 6 (czerwiec 2023). http://dx.doi.org/10.1007/s10714-023-03113-8.

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AbstractWe consider again stationary solutions to the spherically symmetric Einstein–Maxwell–Klein–Gordon system, commonly known as “charged boson stars”, originally studied by Jetzer and Van Der Bij (Phys Lett B 227:341, 1989). We construct families of charged boson stars in the ground state, for different values of the charge parameter q, and different values of the central scalar field. Following Jetzer and Van Der Bij, one can define a critical value for the charge $$q=q_c$$ q = q c that corresponds to the value for which the Coulomb repulsion of the bosonic particles exactly cancels their newtonian gravitational attraction. We confirm the claim made by Pugliese et al. (Phys Rev D, 2013. https://doi.org/10.1103/physrevd.88.024053) that super-critical solutions exist for a limited range of charges above the critical value $$q>q_c$$ q > q c (though we find an even smaller range of q for which this is possible). Our analysis indicates, however, that all such super-critical solutions are gravitationally unbound, and are therefore expected to be unstable. One of the main results of our analysis is the fact that, even though we do find a family of slightly super-critical solutions in the sense that $$q>q_c$$ q > q c , there are no super-critical solutions in the sense that the total charge Q is larger than the total mass M of the system.

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45

Wang, Yi-Li, i Xian-Hui Ge. "Black holes in 4D Einstein–Maxwell–Gauss–Bonnet gravity coupled with scalar fields". European Physical Journal C 81, nr 4 (kwiecień 2021). http://dx.doi.org/10.1140/epjc/s10052-021-09068-x.

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AbstractEinstein–Maxwell–Gauss–Bonnet-axion theory in 4-dimensional spacetime is investigated in this paper through a “Kaluza–Klein-like” process. Dual to systems at finite temperature with background magnetic field on three dimensions, the four-dimensional dyonic black hole solution coupled with higher derivative terms is obtained. After the tensor-type perturbation is added, the shear viscosity to entropy density ratio is calculated at high temperature and low temperature separately. The behaviour of shear viscosity to entropy density ratio of uncharged black holes is found to be similar with that in 5-dimensional spacetime, violating the Kovtun–Starinets–Son bound as well when temperature becomes lower. In addition, the main feature of this ratio remains almost unchanged in 4 dimensions, which is characterised by $$(T/\varDelta )^2$$ ( T / Δ ) 2 at low temperature T, with $$\varDelta $$ Δ proportional to the coefficient $$\beta $$ β from scalar fields. The difficulty in causal analysis is also discussed, which is mainly caused by the vanishing momentum term in equations of motion.

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46

Dehghani, M. "Three-dimensional black holes with scalar hair coupled to a Maxwell-like electrodynamics". Modern Physics Letters A, 6.01.2023. http://dx.doi.org/10.1142/s0217732322502054.

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By consideration of an Einstein-dilaton nonlinear charged gravitating system, it has been shown that this theory is confronted with the problem of indeterminacy. It means that the number of independent differential equations is one less than the number of unknowns. To overcome this problem, the power-law and exponential ansatz functions have been used, separately. Through solving the field equations, in the presence of a Coulomb-like electric field, it has been found that this theory includes two novel classes of charged black holes (BHs) with unusual asymptotic behavior, for each ansatz. It has been found that, under some circumstances, both of the ansatz functions lead to the same results. The novel exact solutions show BHs with one horizon, two horizons and without horizon. Using a Smarr-type mass formula, the validity of the first law of BH thermodynamics (FLT) has been proved, after calculating the thermodynamic and conserved quantities. Making use of thermodynamical and geometrical approaches, thermal stability of the BHs has been analyzed. Results of the aforementioned methods have been compared by use of the plots.

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47

Babaei-Aghbolagh, H., Davood Mahdavian Yekta, Komeil Babaei Velni i H. Mohammadzadeh. "Complexity growth in Gubser–Rocha models with momentum relaxation". European Physical Journal C 82, nr 4 (kwiecień 2022). http://dx.doi.org/10.1140/epjc/s10052-022-10253-9.

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AbstractThe Einstein–Maxwell–Axion–Dilaton (EMAD) theories, based on the Gubser–Rocha (GR) model, are very interesting in holographic calculations of strongly correlated systems in condensed matter physics. Due to the presence of spatially dependent massless axionic scalar fields, the momentum is relaxed, and we have no translational invariance at finite charge density. It would be of interest to study some aspects of quantum information theory for such systems in the context of AdS/CFT where EMAD theory is a holographic dual theory. For instance, in this paper we investigate the complexity and its time dependence for charged AdS black holes of EMAD theories in diverse dimensions via the complexity equals action (CA) conjecture. We will show that the growth rate of the holographic complexity violates Lloyd’s bound at finite times. However, as shown at late times, it depends on the strength of the momentum relaxation and saturates the bound for these black holes.

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48

Khavkine, Igor. "Explicit Triangular Decoupling of the Separated Lichnerowicz Tensor Wave Equation on Schwarzschild into Scalar Regge-Wheeler Equations". Symmetry, Integrability and Geometry: Methods and Applications, 4.02.2022. http://dx.doi.org/10.3842/sigma.2022.011.

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We consider the vector and the Lichnerowicz wave equations on the Schwarzschild spacetime, which correspond to the Maxwell and linearized Einstein equations in harmonic gauges (or, respectively, in Lorenz and de Donder gauges). After a complete separation of variables, the radial mode equations form complicated systems of coupled linear ODEs. We outline a precise abstract strategy to decouple these systems into sparse triangular form, where the diagonal blocks consist of spin-s scalar Regge-Wheeler equations (for spins s=0,1,2). Building on the example of the vector wave equation, which we have treated previously, we complete a successful implementation of our strategy for the Lichnerowicz wave equation. Our results go a step further than previous more ad-hoc attempts in the literature by presenting a full and maximally simplified final triangular form. These results have important applications to the quantum field theory of and the classical stability analysis of electromagnetic and gravitational perturbations of the Schwarzschild black hole in harmonic gauges.

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49

Inkof, Gian Andrea, Joachim M. C. Küppers, Julia M. Link, Blaise Goutéraux i Jörg Schmalian. "Quantum critical scaling and holographic bound for transport coefficients near Lifshitz points". Journal of High Energy Physics 2020, nr 11 (listopad 2020). http://dx.doi.org/10.1007/jhep11(2020)088.

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Abstract The transport behavior of strongly anisotropic systems is significantly richer compared to isotropic ones. The most dramatic spatial anisotropy at a critical point occurs at a Lifshitz transition, found in systems with merging Dirac or Weyl point or near the superconductor-insulator quantum phase transition. Previous work found that in these systems a famous conjecture on the existence of a lower bound for the ratio of a shear viscosity to entropy is violated, and proposed a generalization of this bound for anisotropic systems near charge neutrality involving the electric conductivities. The present study uses scaling arguments and the gauge-gravity duality to confirm the previous analysis of universal bounds in anisotropic Dirac systems. We investigate the strongly-coupled phase of quantum Lifshitz systems in a gravitational Einstein-Maxwell-dilaton model with a linear massless scalar which breaks translations in the boundary dual field theory and sources the anisotropy. The holographic computation demonstrates that some elements of the viscosity tensor can be related to the ratio of the electric conductivities through a simple geometric ratio of elements of the bulk metric evaluated at the horizon, and thus obey a generalized bound, while others violate it. From the IR critical geometry, we express the charge diffusion constants in terms of the square butterfly velocities. The proportionality factor turns out to be direction-independent, linear in the inverse temperature, and related to the critical exponents which parametrize the anisotropic scaling of the dual field theory.

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