Nonlinear Electrodynamics and Magnetic Black Holes

A new modified Hayward metric of magnetically charged non-singular black hole spacetime in the framework of nonlinear electrodynamics is constructed. When the fundamental length introduced, characterising quantum gravity effects, vanishes, one comes to the general relativity coupled with the Bronnikov model of nonlinear electrodynamics. The metric can have one (an extreme) horizon, two horizons of black holes, or no horizons corresponding to the particle-like solution. Corrections to the Reissner–Nordström solution are found as the radius approaches infinity. As r → 0 the metric has a de Sitter core showing the absence of singularities, the asymptotic of the Ricci and Kretschmann scalars are obtained and they are finite everywhere. The thermodynamics of black holes, by calculating the Hawking temperature and the heat capacity, is studied. It is demonstrated that phase transitions take place when the Hawking temperature possesses the maximum. Black holes are thermodynamically stable at some range of parameters.

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Three-dimensional static black hole with Λ and nonlinear electromagnetic fields and its thermodynamics

International Journal of Modern Physics D ◽

10.1142/s0218271819501608 ◽

2019 ◽

Vol 28 (12) ◽

pp. 1950160

Author(s):

M. B. Tataryn ◽

M. M. Stetsko

Keyword(s):

Black Holes ◽

Black Hole ◽

Electromagnetic Fields ◽

Three Dimensional ◽

Nonlinear Electrodynamics ◽

Extended Phase Space ◽

Field Equations ◽

Extended Phase ◽

Dimensional Spacetime ◽

Static Black Hole

Static black hole with the Power Maxwell invariant (PMI), Born–Infeld (BI), logarithmic (LN), exponential (EN) electromagnetic fields in three-dimensional spacetime with cosmological constant was studied. It was shown that the LN and EN fields represent the Born–Infeld type of nonlinear electrodynamics. It the framework of General Relativity the exact solutions of the field equations were obtained, corresponding thermodynamic functions were calculated and the [Formula: see text] criticality of the black holes in the extended phase-space thermodynamics was investigated.

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Thermodynamics and reentrant phase transition for logarithmic nonlinear charged black holes in massive gravity

International Journal of Modern Physics D ◽

10.1142/s0218271820500819 ◽

2020 ◽

Vol 29 (12) ◽

pp. 2050081

Author(s):

S. Rajaee Chaloshtary ◽

M. Kord Zangeneh ◽

S. Hajkhalili ◽

A. Sheykhi ◽

S. M. Zebarjad

Keyword(s):

Phase Transition ◽

Black Holes ◽

Black Hole ◽

Quantum Effect ◽

Massive Gravity ◽

Nonlinear Electrodynamics ◽

Model Parameters ◽

Thermodynamic Quantities ◽

Field Equations ◽

Black Hole Solutions

We investigate a new class of [Formula: see text]-dimensional topological black hole solutions in the context of massive gravity and in the presence of logarithmic nonlinear electrodynamics. Exploring higher-dimensional solutions in massive gravity coupled to nonlinear electrodynamics is motivated by holographic hypothesis as well as string theory. We first construct exact solutions of the field equations and then explore the behavior of the metric functions for different values of the model parameters. We observe that our black holes admit the multi-horizons caused by a quantum effect called anti-evaporation. Next, by calculating the conserved and thermodynamic quantities, we obtain a generalized Smarr formula. We find that the first law of black holes thermodynamics is satisfied on the black hole horizon. We study thermal stability of the obtained solutions in both canonical and grand canonical ensembles. We reveal that depending on the model parameters, our solutions exhibit a rich variety of phase structures. Finally, we explore, for the first time without extending thermodynamics phase space, the critical behavior and reentrant phase transition for black hole solutions in massive gravity theory. We realize that there is a zeroth-order phase transition for a specified range of charge value and the system experiences a large/small/large reentrant phase transition due to the presence of nonlinear electrodynamics.

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Dynamics of Electromagnetic Fields and Structure of Regular Rotating Electrically Charged Black Holes and Solitons in Nonlinear Electrodynamics Minimally Coupled to Gravity

Universe ◽

10.3390/universe5100205 ◽

2019 ◽

Vol 5 (10) ◽

pp. 205 ◽

Cited By ~ 6

Author(s):

Irina Dymnikova ◽

Evgeny Galaktionov

Keyword(s):

Black Holes ◽

Electromagnetic Fields ◽

Nonlinear Electrodynamics ◽

Axially Symmetric ◽

De Sitter ◽

Dynamical Equations ◽

Naked Singularities ◽

Charged Black Holes ◽

De Sitter Vacuum ◽

Electrically Charged

We study the dynamics of electromagnetic fields of regular rotating electrically charged black holes and solitons replacing naked singularities in nonlinear electrodynamics minimally coupled to gravity (NED-GR). They are related by electromagnetic and gravitational interactions and described by the axially symmetric NED-GR solutions asymptotically Kerr-Newman for a distant observer. Geometry is described by the metrics of the Kerr-Schild class specified by T t t = T r r ( p r = − ρ ) in the co-rotating frame. All regular axially symmetric solutions obtained from spherical solutions with the Newman-Janis algorithm belong to this class. The basic generic feature of all regular objects of this class, both electrically charged and electrically neutral, is the existence of two kinds of de Sitter vacuum interiors. We analyze the regular solutions to dynamical equations for electromagnetic fields and show which kind of a regular interior is favored by electromagnetic dynamics for NED-GR objects.

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REGULAR BLACK HOLES IN AN ASYMPTOTICALLY DE SITTER UNIVERSE

Modern Physics Letters A ◽

10.1142/s0217732308028715 ◽

2008 ◽

Vol 23 (40) ◽

pp. 3377-3392 ◽

Cited By ~ 20

Author(s):

JERZY MATYJASEK ◽

DARIUSZ TRYNIECKI ◽

MARIUSZ KLIMEK

Keyword(s):

Black Holes ◽

Black Hole ◽

Nonlinear Electrodynamics ◽

Spherically Symmetric ◽

De Sitter ◽

Coupled Equations ◽

Sitter Universe ◽

De Sitter Universe ◽

Horizon Geometry ◽

Interesting Solution

A regular solution of the system of coupled equations of the nonlinear electrodynamics and gravity describing static and spherically-symmetric black holes in an asymptotically de Sitter universe is constructed and analyzed. Special emphasis is put on the degenerate configurations (when at least two horizons coincide) and their near horizon geometry. It is explicitly demonstrated that approximating the metric potentials in the region between the horizons by simple functions and making use of a limiting procedure one obtains the solutions constructed from maximally symmetric subspaces with different absolute values of radii. Topologically they are AdS2×S2 for the cold black hole, dS2×S2 when the event and cosmological horizon coincide, and the Plebański–Hacyan solution for the ultraextremal black hole. A physically interesting solution describing the lukewarm black holes is briefly analyzed.

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