scholarly journals Wormhole Solutions in the Presence of Nonlinear Maxwell Field

2014 ◽  
Vol 2014 ◽  
pp. 1-11 ◽  
Author(s):  
S. H. Hendi
Keyword(s):  
Electromagnetic Field ◽  
Lower Bound ◽  
Maxwell Field ◽  
Nonlinear Electrodynamics ◽  
Radial Coordinate ◽  
Conserved Quantities ◽  
Static Solutions

In generalizing the Maxwell field to nonlinear electrodynamics, we look for the magnetic solutions. We consider a suitable real metric with a lower bound on the radial coordinate and investigate the properties of the solutions. We find that in order to have a finite electromagnetic field near the lower bound, we should replace the Born-Infeld theory with another nonlinear electrodynamics theory. Also, we use the cut-and-paste method to construct wormhole structure. We generalize the static solutions to rotating spacetime and obtain conserved quantities.

scholarly journals GENERALIZED EINSTEIN–MAXWELL FIELD EQUATIONS IN THE PALATINI FORMALISM

2013 ◽  
Vol 22 (04) ◽  
pp. 1350017 ◽  
Author(s):  
GINÉS R. PÉREZ TERUEL
Keyword(s):  
Electromagnetic Field ◽  
Algebraic Equation ◽  
Ricci Tensor ◽  
Maxwell Equations ◽  
Natural Generalization ◽  
New Method ◽  
Maxwell Field ◽  
Field Equations ◽  
Palatini Formalism

We derive a new set of field equations within the framework of the Palatini formalism. These equations are a natural generalization of the Einstein–Maxwell equations which arise by adding a function [Formula: see text], with [Formula: see text] to the Palatini Lagrangian f(R, Q). The result we obtain can be viewed as the coupling of gravity with a nonlinear extension of the electromagnetic field. In addition, a new method is introduced to solve the algebraic equation associated to the Ricci tensor.

scholarly journals Gauge-independent Theory of Symmetry. I.

1964 ◽  
Vol 17 (4) ◽  
pp. 431 ◽  
Author(s):  
LJ Tassie ◽  
HA Buchdahl
Keyword(s):  
Electromagnetic Field ◽  
Single Particle ◽  
Equations Of Motion ◽  
Classical Mechanics ◽  
Conserved Quantities ◽  
Continuous Symmetry ◽  
Symmetry Properties ◽  
Symmetry Transformations ◽  
Hamiltonian Forms

The invariance of a system under a given transformation of coordinates is usually taken to mean that its Lagrangian is invariant under that transformation. Consequently, whether or not the system is invariant will depend on the gauge used in describing the system. By defining invariance of a system to mean the invariance of its equations of motion, a gauge-independent theory of symmetry properties is obtained for classical mechanics in both the Lagrangian and Hamiltonian forms. The conserved quantities associated with continuous symmetry transformations are obtained. The system of a single particle moving in a given electromagnetic field is considered in detail for various symmetries of the electromagnetic field, and the appropriate conserved quantities are found.

scholarly journals Slowly Rotating Black Holes with Nonlinear Electrodynamics

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
S. H. Hendi ◽  
M. Allahverdizadeh
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Angular Momentum ◽  
Linear Order ◽  
Rotation Parameter ◽  
Nonlinear Electrodynamics ◽  
Nonlinearity Parameter ◽  
Static Solutions ◽  
Rotating Black Holes ◽  
Spherical Topology

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 parameteraas well as the nonlinearity parameterβ. In the limitβ→∞, the solution describes slowly rotating AdS type black holes.

scholarly journals Energy Distribution of a Regular Black Hole Solution in Einstein-Nonlinear Electrodynamics

2015 ◽  
Vol 2015 ◽  
pp. 1-12 ◽  
Author(s):  
I. Radinschi ◽  
F. Rahaman ◽  
Th. Grammenos ◽  
A. Spanou ◽  
Sayeedul Islam
Keyword(s):  
Black Hole ◽  
Positive Integer ◽  
Energy Distribution ◽  
Black Hole Solution ◽  
Mass Function ◽  
Nonlinear Electrodynamics ◽  
Radial Coordinate ◽  
Regular Black Hole ◽  
Limiting Behavior ◽  
Special Case

A study about the energy momentum of a new four-dimensional spherically symmetric, static and charged, regular black hole solution developed in the context of general relativity coupled to nonlinear electrodynamics is presented. Asymptotically, this new black hole solution behaves as the Reissner-Nordström solution only for the particular valueμ=4, whereμis a positive integer parameter appearing in the mass function of the solution. The calculations are performed by use of the Einstein, Landau-Lifshitz, Weinberg, and Møller energy momentum complexes. In all the aforementioned prescriptions, the expressions for the energy of the gravitating system considered depend on the massMof the black hole, its chargeq, a positive integerα, and the radial coordinater. In all these pseudotensorial prescriptions, the momenta are found to vanish, while the Landau-Lifshitz and Weinberg prescriptions give the same result for the energy distribution. In addition, the limiting behavior of the energy for the casesr→∞,r→0, andq=0is studied. The special caseμ=4andα=3is also examined. We conclude that the Einstein and Møller energy momentum complexes can be considered as the most reliable tools for the study of the energy momentum localization of a gravitating system.

scholarly journals Extended phase space of AdS black holes in Einstein–Gauss–Bonnet gravity with a quadratic nonlinear electrodynamics

2016 ◽  
Vol 25 (06) ◽  
pp. 1650063 ◽  
Author(s):  
S. H. Hendi ◽  
S. Panahiyan ◽  
M. Momennia
Keyword(s):  
Black Holes ◽  
Electromagnetic Field ◽  
Phase Space ◽  
Phase Diagrams ◽  
Van Der Waals ◽  
Critical Values ◽  
Nonlinear Electrodynamics ◽  
Maxwell Theory ◽  
Unusual Behavior ◽  
Extended Phase

In this paper, we consider quadratic Maxwell invariant as a correction to the Maxwell theory and study thermodynamic behavior of the black holes in Einstein and Gauss–Bonnet gravities. We consider cosmological constant as a thermodynamic pressure to extend phase space. Next, we obtain critical values in case of variation of nonlinearity and Gauss–Bonnet parameters. Although the general thermodynamical behavior of the black hole solutions is the same as usual Van der Waals system, we show that in special case of the nonlinear electromagnetic field, there will be a turning point for the phase diagrams and usual Van der Waals is not observed. This theory of nonlinear electromagnetic field provides two critical horizon radii. We show that this unusual behavior of phase diagrams is due to existence of second critical horizon radius. It will be pointed out that the power of the gravity and nonlinearity of the matter field modify the critical values. We generalize the study by considering the effects of dimensionality on critical values and make comparisons between our models with their special sub-classes. In addition, we examine the possibility of the existence of the reentrant phase transitions through two different methods.

On the instability of localized EM pulses in nonlinear electrodynamics with account of temperature effects

2021 ◽  
Vol 35 (10) ◽  
pp. 2150176
Author(s):  
Mikhail B. Belonenko ◽  
Natalia N. Konobeeva ◽  
Alexander V. Zhukov
Keyword(s):  
Electromagnetic Field ◽  
Pair Production ◽  
Temperature Effects ◽  
Electromagnetic Pulse ◽  
Maxwell’S Equations ◽  
Maxwell's Equations ◽  
Nonlinear Electrodynamics ◽  
Influence Of Temperature ◽  
Schwinger Mechanism

Based on Maxwell’s equations, we study the development of electromagnetic pulse instability in nonlinear electrodynamics beyond approximation of slowly varying amplitudes and phases. The action was chosen from the Heisenberg–Euler Lagrangian based on the invariants of the electromagnetic field. We analyze the scenario for the evolution of instability, which turns out to be consistent with the earlier conclusion done within the approximation of slowly varying amplitudes and phases. In this study, we take into account the influence of temperature. The rate of pair production under the Schwinger mechanism is estimated.

scholarly journals Energy-Momentum for a Charged Nonsingular Black Hole Solution with a Nonlinear Mass Function

2017 ◽  
Vol 2017 ◽  
pp. 1-10 ◽  
Author(s):  
Irina Radinschi ◽  
Theophanes Grammenos ◽  
Farook Rahaman ◽  
Andromahi Spanou ◽  
Sayeedul Islam ◽  
...  
Keyword(s):  
Black Hole ◽  
Energy Distribution ◽  
Black Hole Solution ◽  
Mass Function ◽  
Nonlinear Electrodynamics ◽  
Logistic Distribution ◽  
Radial Coordinate ◽  
Additional Parameter ◽  
Limiting Behavior ◽  
Energy And Momentum

The energy-momentum of a new four-dimensional, charged, spherically symmetric, and nonsingular black hole solution constructed in the context of general relativity coupled to a theory of nonlinear electrodynamics is investigated, whereby the nonlinear mass function is inspired by the probability density function of the continuous logistic distribution. The energy and momentum distributions are calculated by use of the Einstein, Landau-Lifshitz, Weinberg, and Møller energy-momentum complexes. In all these prescriptions, it is found that the energy distribution depends on the mass M and the charge q of the black hole, an additional parameter β coming from the gravitational background considered, and the radial coordinate r. Further, the Landau-Lifshitz and Weinberg prescriptions yield the same result for the energy, while, in all the aforesaid prescriptions, all the momenta vanish. We also focus on the study of the limiting behavior of the energy for different values of the radial coordinate, the parameter β, and the charge q. Finally, it is pointed out that, for r→∞ and q=0, all the energy-momentum complexes yield the same expression for the energy distribution as in the case of the Schwarzschild black hole solution.

Einstein–Maxwell fields with plane symmetry. I

1970 ◽  
Vol 67 (1) ◽  
pp. 127-131 ◽  
Author(s):  
S. Patnaik
Keyword(s):  
Static Solution ◽  
Empty Space ◽  
Maxwell Field ◽  
Subsequent Paper ◽  
Plane Symmetry ◽  
Static Charge ◽  
Field Equations ◽  
Metric Tensor ◽  
Static Solutions ◽  
Maxwell Fields

An exact static solution of the system of Einstein–Maxwell field equations in the absence of charge is obtained when both the metric tensor gαβ and the Maxwell field tensor Fαβ exhibits plane symmetry in the sense that both remain invariant under the group of motions that characterize plane symmetry. Our solution generalizes the empty space-time solution with plane symmetry previously obtained by Taub to the situation when static charge-free electromagnetic fields are present. We hope to discuss non-static solutions of Einstein–Maxwell fields with plane symmetry as well as some other considerations in a subsequent paper.

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