Charged black holes coupled to non-linear electrodynamics in scalar-tensor theories of gravity with massless scalar field

2007 ◽  
Author(s):  
Ivan Zh. Stefanov ◽  
Stoytcho S. Yazadjiev ◽  
Michail D. Todorov
Keyword(s):  
Black Holes ◽  
Scalar Field ◽  
Massless Scalar ◽  
Massless Scalar Field ◽  
Charged Black Holes ◽  
Non Linear ◽  
Theories Of Gravity

scholarly journals SCALAR–TENSOR BLACK HOLES COUPLED TO EULER–HEISENBERG NONLINEAR ELECTRODYNAMICS

2007 ◽  
Vol 22 (17) ◽  
pp. 1217-1231 ◽  
Author(s):  
IVAN ZH. STEFANOV ◽  
STOYTCHO S. YAZADJIEV ◽  
MICHAIL D. TODOROV
Keyword(s):  
Black Holes ◽  
Scalar Field ◽  
Numerical Solutions ◽  
Causal Structure ◽  
Nonlinear Electrodynamics ◽  
Massless Scalar ◽  
Massless Scalar Field ◽  
Charged Black Holes ◽  
Maxwell Electrodynamics ◽  
Scalar Hair

The no-scalar-hair conjecture rules out the existence of asymptotically flat black holes with a scalar dressing for a large class of theories. No-scalar-hair theorems have been proved for the cases of neutral black holes and for charged black holes in the Maxwell electrodynamics. These theorems, however, do not apply in the case of nonlinear electrodynamics. In the present work numerical solutions describing charged black holes coupled to Euler–Heisenberg type nonlinear electrodynamics in scalar–tensor theories of gravity with massless scalar field are found. In comparison to the corresponding solution in General Relativity the presented solution has a simpler causal structure the reason for which is the presence of the scalar field. The present class of black holes has a single, nondegenerate horizon, i.e. its causal structure resembles that of the Schwarzschild black hole.

scholarly journals BORN–INFELD BLACK HOLES COUPLED TO A MASSIVE SCALAR FIELD

2011 ◽  
Vol 20 (13) ◽  
pp. 2471-2496 ◽  
Author(s):  
DANIELA A. GEORGIEVA ◽  
IVAN ZH. STEFANOV ◽  
STOYTCHO S. YAZADJIEV ◽  
MICHAIL D. TODOROV
Keyword(s):  
Black Holes ◽  
Scalar Field ◽  
Causal Structure ◽  
Analytical Techniques ◽  
Massless Scalar ◽  
Massless Scalar Field ◽  
Massive Scalar ◽  
Massive Scalar Field ◽  
Theories Of Gravity ◽  
Extremal Black Holes

Born–Infeld black holes in the scalar–tensor theories of gravity with massless scalar field have been recently obtained [I. Stefanov, S. Yazadjiev and M. Todorov, Phys. Rev. D75 (2007) 084036; Mod. Phys. Lett. A.23(34) (2008) 2915; Class. Quantum Gravity26 (2009) 015006]. The aim of the current paper is to study the effect of the inclusion of a potential for the scalar field in the theory, through a combination of analytical techniques and numerical methods. The black holes coupled to a massive scalar field have richer causal structure in comparison to the massless scalar field case. In the former case, the black holes may have a second, inner horizon. The presence of potential for the scalar field allows the existence of extremal black holes for certain values of the mass of the scalar field and the magnetic (electric) charge of the black hole. The solutions are stable against spherically symmetric perturbations. Arguments in favor of the general stability of the solutions coming from the application of the "turning point" method are also presented.

scholarly journals On black hole structures in scalar–tensor theories of gravity

2016 ◽  
Vol 25 (09) ◽  
pp. 1641005 ◽  
Author(s):  
Kirill A. Bronnikov ◽  
Júlio C. Fabris ◽  
Denis C. Rodrigues
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Scalar Field ◽  
Metric Regularity ◽  
Massless Scalar ◽  
Massless Scalar Field ◽  
Singular Behavior ◽  
Nonminimal Coupling ◽  
Theories Of Gravity ◽  
Scalar Gravity

We review some properties of black hole structures appearing in gravity with a massless scalar field, with both minimal and nonminimal coupling. The main properties of the resulting cold black holes are described. The study of black holes in scalar-gravity systems is extended to [Formula: see text]-essence theories, and some examples are explicitly worked out. In these cases, even while the existence of horizons is possible, the metric regularity requirement on the horizon implies either a cold black type structure or a singular behavior of the scalar field.

scholarly journals COLLAPSING SCALAR FIELD WITH KINEMATIC SELF-SIMILARITY OF THE SECOND KIND IN (2+1) GRAVITY

2005 ◽  
Vol 14 (06) ◽  
pp. 1049-1061 ◽  
Author(s):  
R. CHAN ◽  
M. F. A. DA SILVA ◽  
J. F. VILLAS DA ROCHA ◽  
ANZHONG WANG
Keyword(s):  
Black Holes ◽  
Scalar Field ◽  
Gravitational Collapse ◽  
Massless Scalar ◽  
Massless Scalar Field ◽  
Field Equations ◽  
Self Similarity ◽  
Global Properties ◽  
Scalar Field Equations

All the (2+1)-dimensional circularly symmetric solutions with kinematic self-similarity of the second kind to the Einstein-massless-scalar field equations are found and their local and global properties are studied. It is found that some of them represent gravitational collapse of a massless scalar field, in which black holes are always formed.

scholarly journals DISCUSSION ON SOME CHARACTERISTICS OF CHARGED BRANE-WORLD BLACK HOLES

2009 ◽  
Vol 24 (04) ◽  
pp. 719-739 ◽  
Author(s):  
M. KALAM ◽  
F. RAHAMAN ◽  
A. GHOSH ◽  
B. RAYCHAUDHURI
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Gravitational Field ◽  
Scalar Field ◽  
Brane World ◽  
Massless Scalar ◽  
Massless Scalar Field ◽  
Effective Potentials ◽  
Test Particles ◽  
Jacobi Formalism

Several physical natures of charged brane-world black holes are investigated. Firstly, the timelike 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 the charged brane-world black holes using the Hamilton–Jacobi formalism. We consider charged and uncharged test particles and examine their behavior in both static and nonstatic cases. Thirdly, the thermodynamics of the charged brane-world black holes are studied. Finally, it is shown that there is no phenomenon of superradiance for an incident massless scalar field for such a black hole.

scholarly journals GRAVITATIONAL COLLAPSE OF MASSLESS SCALAR FIELD WITH NEGATIVE COSMOLOGICAL CONSTANT IN (2+1) DIMENSIONS

2006 ◽  
Vol 15 (04) ◽  
pp. 545-557 ◽  
Author(s):  
R. CHAN ◽  
M. F. A. DA SILVA ◽  
JAIME F. VILLAS DA ROCHA
Keyword(s):  
Black Holes ◽  
Scalar Field ◽  
Cosmological Constant ◽  
Gravitational Collapse ◽  
Massless Scalar ◽  
Massless Scalar Field ◽  
Field Equations ◽  
Negative Cosmological Constant ◽  
Global Properties ◽  
Scalar Field Equations

The (2+1)-dimensional geodesic circularly symmetric solutions of Einstein-massless-scalar field equations with negative cosmological constant are found and their local and global properties are studied. It is found that one of them represents gravitational collapse where black holes are always formed.

scholarly journals Non-linear composition and infinite conformal symmetry of topologically non-trivial solutions in $$(3+1)$$-dimensional Yang–Mills theory

2021 ◽  
Vol 81 (11) ◽  
Author(s):  
Fabrizio Canfora
Keyword(s):  
Scalar Field ◽  
Charge Density ◽  
Topological Charge ◽  
Conformal Symmetry ◽  
Analytic Solutions ◽  
Massless Scalar ◽  
Massless Scalar Field ◽  
Field Equations ◽  
Yang Mills ◽  
Non Linear

AbstractAn infinite-dimensional family of analytic solutions in pure SU(2) Yang–Mills theory at finite density in $$(3+1)$$ ( 3 + 1 ) dimensions is constructed. It is labelled by two integeres (p and q) as well as by a two-dimensional free massless scalar field. The gauge field depends on all the 4 coordinates (to keep alive the topological charge) but in such a way to reduce the (3+1)-dimensional Yang–Mills field equations to the field equation of a 2D free massless scalar field. For each p and q, both the on-shell action and the energy-density reduce to the action and Hamiltonian of the corresponding 2D CFT. The topological charge density associated to the non-Abelian Chern–Simons current is non-zero. It is possible to define a non-linear composition within this family as if these configurations were “Lego blocks”. The non-linear effects of Yang–Mills theory manifest themselves since the topological charge density of the composition of two solutions is not the sum of the charge densities of the components. This leads to an upper bound on the amplitudes in order for the topological charge density to be well-defined. This suggests that if the temperature and/or the energy is/are high enough, the topological density of these configurations is not well-defined anymore. Semiclassically, one can show that (depending on whether the topological charge is even or odd) some of the operators appearing in the 2D CFT should be quantized as Fermions (despite the Bosonic nature of the classical field).

scholarly journals GRAVITATIONAL COLLAPSE OF A MASSLESS SCALAR FIELD AND A PERFECT FLUID WITH SELF-SIMILARITY OF THE FIRST KIND IN 2+1 DIMENSIONS

2008 ◽  
Vol 17 (11) ◽  
pp. 2143-2158 ◽  
Author(s):  
F. I. M. PEREIRA ◽  
R. CHAN
Keyword(s):  
Black Holes ◽  
Scalar Field ◽  
Perfect Fluid ◽  
Gravitational Collapse ◽  
Massless Scalar ◽  
Massless Scalar Field ◽  
Self Similarity ◽  
Global Properties ◽  
Self Similar ◽  
Similar Solutions

Self-similar solutions of a collapsing perfect fluid and a massless scalar field with kinematic self-similarity of the first kind in 2+1 dimensions are obtained. The local and global properties of the solutions are studied. It is found that some of them represent gravitational collapse, in which black holes are always formed, and some may be interpreted as representing cosmological models.

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