scholarly journals CHARGE-CONFINING GRAVITATIONAL ELECTROVACUUM SHOCK WAVE

2014 ◽  
Vol 29 (03) ◽  
pp. 1450020 ◽  
Author(s):  
EDUARDO GUENDELMAN ◽  
EMIL NISSIMOV ◽  
SVETLANA PACHEVA
Keyword(s):  
Shock Wave ◽  
Nonlinear Electrodynamics ◽  
Spherically Symmetric ◽  
Square Root ◽  
De Sitter ◽  
Asymptotically Flat ◽  
Test Particles ◽  
Additional Constant ◽  
Finite Distance ◽  
Charged Test

In previous publications, we have extensively studied spherically symmetric solutions of gravity coupled to a nonstandard type of nonlinear electrodynamics containing a square-root of the ordinary Maxwell Lagrangian (the latter is known to yield quantum chromodynamic (QCD)-like confinement in a flat spacetime). A class of these solutions describe nonstandard black holes of Reissner–Nordström–(anti-)-de Sitter type with an additional constant radial vacuum electric field, in particular, a non-asymptotically flat Reissner–Nordström-type black hole. Here, we study the ultra-relativistic boost (Lousto–Sanchez extension of Aichelburg–Sexl) limit of the latter and show that, unlike the ordinary Reissner–Nordström case, we obtain a gravitational electrovacuum shock wave as a result of the persistence of the gauge field due to the "square-root" Maxwell Lagrangian term. Next, we show that this gravitational electrovacuum shock wave confines charged test particles (both massive and massless) within a finite distance from its front.

scholarly journals Motion of spinning particles in non asymptotically flat spacetimes

2020 ◽  
Vol 80 (7) ◽  
Author(s):  
Bobir Toshmatov ◽  
Ozodbek Rahimov ◽  
Bobomurat Ahmedov ◽  
Daniele Malafarina
Keyword(s):  
Vacuum Energy ◽  
Spherically Symmetric ◽  
Combined Effects ◽  
Circular Orbits ◽  
Spinning Particles ◽  
Asymptotically Flat ◽  
Asymptotic Flatness ◽  
Test Particles ◽  
Cosmological Context ◽  
Flat Spacetimes

Abstract The assumption of asymptotic flatness for isolated astrophysical bodies may be considered an approximation when one considers a cosmological context where a cosmological constant or vacuum energy is present. In this framework we study the motion of spinning particles in static, spherically symmetric and asymptotically non-flat spacetimes with repulsive cosmological vacuum energy and quintessential field. Due to the combined effects of gravitational attraction and cosmological repulsion, the region where stable circular orbits are allowed is restricted by an innermost and an outermost stable circular orbits. We show that taking into account the spin of test particles may enlarge or shrink the region of allowed stable circular orbits depending on whether the spin is co-rotating or counter-rotating with the angular momentum of the particles.

scholarly journals REGULAR BLACK HOLES IN AN ASYMPTOTICALLY DE SITTER UNIVERSE

2008 ◽  
Vol 23 (40) ◽  
pp. 3377-3392 ◽  
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.

EXACT SOLUTIONS OF DILATON GRAVITY WITH (ANTI)-DE SITTER ASYMPTOTICS

2014 ◽  
Vol 29 (02) ◽  
pp. 1450010 ◽  
Author(s):  
S. MIGNEMI
Keyword(s):  
Black Hole ◽  
Exact Solutions ◽  
Maxwell Field ◽  
Spherically Symmetric ◽  
Dilaton Gravity ◽  
De Sitter ◽  
Asymptotically Flat ◽  
Black Hole Solutions

We present a technique for obtaining exact spherically symmetric asymptotically de Sitter (dS) or anti-de Sitter (adS) black hole solutions of dilaton gravity with generic coupling to Maxwell field, starting from asymptotically flat solutions and adding a suitable dilaton potential to the action.

scholarly journals Energy of test objects on black hole spacetimes: A brief review

2015 ◽  
Vol 24 (14) ◽  
pp. 1550103 ◽  
Author(s):  
Alejandro Corichi
Keyword(s):  
Black Hole ◽  
Asymptotic Region ◽  
Gravitational Potential Energy ◽  
De Sitter ◽  
Conservation Of Energy ◽  
Asymptotically Flat ◽  
Black Hole Spacetimes ◽  
Test Particles ◽  
Exterior Regions ◽  
Test Objects

In this paper, we review the issue of defining energy for test particles on a background stationary spacetime. We revisit different notions of energy as defined by different observers. As is well-known, the existence of a timelike isometry allows for the notion of total conserved energy to be well defined. We use this well-known quantity to show that a gravitational potential energy can be consistently defined. As examples, we study the case of the exterior regions of an asymptotically flat black hole and of the [Formula: see text] Schwarzschild–de Sitter (SdS) case, where an asymptotic region is not available. We then consider the situation in which the test particle is absorbed by the black hole and analyze the energetics in detail. In particular, we show that the notion of horizon energy as defined by the isolated horizons formalism provides a satisfactory notion of energy compatible with the particle’s total conserved energy. With these choices, there is a global conservation of energy. Finally, we comment on a recent proposal to define energy of the black hole as seen by a nearby observer at rest, for which this feature is lost.

scholarly journals Newtonian wormholes with spherical symmetry and tidal forces on test particles

2015 ◽  
Vol 24 (09) ◽  
pp. 1542020 ◽  
Author(s):  
Paulo Luz ◽  
José P. S. Lemos
Keyword(s):  
Black Holes ◽  
Mass Density ◽  
Particle Dynamics ◽  
Spherically Symmetric ◽  
Tidal Effects ◽  
Curved Space ◽  
Asymptotically Flat ◽  
Newtonian Gravitation ◽  
Tidal Forces ◽  
Test Particles

A spherically symmetric wormhole in Newtonian gravitation in curved space, enhanced with a connection between the mass density and the Ricci scalar, is presented. The wormhole, consisting of two connected asymptotically flat regions, inhabits a spherically symmetric curved space. The gravitational potential, gravitational field and the pressure that supports the fluid that permeates the Newtonian wormhole are computed. Particle dynamics and tidal effects in this geometry are studied. The possibility of having Newtonian black holes in this theory is sketched.

scholarly journals Particle Motion around Charged Black Holes in Generalized Dilaton-Axion Gravity

2018 ◽  
Vol 2018 ◽  
pp. 1-8
Author(s):  
Susmita Sarkar ◽  
Farook Rahaman ◽  
Irina Radinschi ◽  
Theophanes Grammenos ◽  
Joydeep Chakraborty
Keyword(s):  
Black Holes ◽  
Gravitational Field ◽  
Effective Potential ◽  
Particle Motion ◽  
Spherically Symmetric ◽  
Asymptotically Flat ◽  
Four Dimensions ◽  
Charged Black Holes ◽  
Test Particles ◽  
Massive Particles

The behaviour of massive and massless test particles around asymptotically flat and spherically symmetric, charged black holes in the context of generalized dilaton-axion gravity in four dimensions is studied. All the possible motions are investigated by calculating and plotting the corresponding effective potential for the massless and massive particles as well. Further, the motion of massive (charged or uncharged) test particles in the gravitational field of charged black holes in generalized dilaton-axion gravity for the cases of static and nonstatic equilibrium is investigated by applying the Hamilton-Jacobi approach.

scholarly journals Existence of Electrically Charged Structures with Regular Center in Nonlinear Electrodynamics Minimally Coupled to Gravity

2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Irina Dymnikova ◽  
Evgeny Galaktionov ◽  
Eduard Tropp
Keyword(s):  
Electric Field ◽  
Energy Condition ◽  
Weak Field ◽  
Nonlinear Electrodynamics ◽  
Spherically Symmetric ◽  
De Sitter ◽  
Field Limit ◽  
Weak Field Limit ◽  
Symmetric Configuration ◽  
Electrically Charged

We address the question of correct description of Lagrange dynamics for regular electrically charged structures in nonlinear electrodynamics coupled to gravity. Regular spherically symmetric configuration satisfying the weak energy condition has obligatory de Sitter center in which the electric field vanishes while the energy density of electromagnetic vacuum achieves its maximal value. The Maxwell weak field limitLF→Fasr→∞requires vanishing electric field at infinity. A field invariantFevolves between two minus zero in the center and at infinity which makes a LagrangianLFwith nonequal asymptotic limits inevitably branching. We formulate the appropriate nonuniform variational problem including the proper boundary conditions and present the example of the spherically symmetric Lagrangian describing electrically charged structure with the regular center.

scholarly journals Regular rotating electrically charged structures in nonlinear electrodynamics minimally coupled to gravity

2016 ◽  
Vol 41 ◽  
pp. 1660120 ◽  
Author(s):  
Irina Dymnikova ◽  
Evgeny Galaktionov
Keyword(s):  
Energy Condition ◽  
Weak Energy Condition ◽  
Nonlinear Electrodynamics ◽  
Perfect Conductor ◽  
Spherically Symmetric ◽  
Axially Symmetric ◽  
De Sitter ◽  
Superconducting Current ◽  
De Sitter Vacuum ◽  
Electrically Charged

In nonlinear electrodynamics minimally coupled to gravity, regular spherically symmetric electrically charged solutions satisfy the weak energy condition and have obligatory de Sitter center. By the Gürses-Gürsey algorithm they are transformed to regular axially symmetric solutions asymptotically Kerr-Newman for a distant observer. Rotation transforms de Sitter center into de Sitter equatorial disk embedded as a bridge into a de Sitter vacuum surface. The de Sitter surfaces satisfy [Formula: see text] and have properties of a perfect conductor and ideal diamagnetic. The Kerr ring singularity is replaced with the superconducting current which serves as a non-dissipative electromagnetic source of the asymptotically Kerr-Newman geometry. Violation of the weak energy condition is prevented by the basic requirement of electrodynamics of continued media.

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