scholarly journals Static spherically symmetric Einstein-Yang-Mills-dilaton black hole and its thermodynamics

2020 ◽  
Vol 101 (12) ◽  
Author(s):  
M. M. Stetsko
2015 ◽  
pp. 41-48 ◽  
Author(s):  
C. Blaga

In this paper we study the timelike geodesics around a spherically symmetric charged dilaton black hole. The trajectories around the black hole are classified using the effective potential of a free test particle. This qualitative approach enables us to determine the type of orbit described by test particle without solving the equations of motion, if the parameters of the black hole and the particle are known. The connections between these parameters and the type of orbit described by the particle are obtained. To visualize the orbits we solve numerically the equation of motion for different values of parameters envolved in our analysis. The effective potential of a free test particle looks different for a non-extremal and an extremal black hole, therefore we have examined separately these two types of black holes.


1999 ◽  
Vol 08 (05) ◽  
pp. 635-643 ◽  
Author(s):  
S. YAZADJIEV

Classes of exact static solutions in four-dimensional Einstein–Maxwell-dilaton gravity are found. Besides the well-known solutions previously found in the literature, new solutions are presented. It is shown that spherically symmetric solutions, except for the case of a charged dilaton black hole, represent globally naked strong curvature singularities.


2004 ◽  
Vol 19 (29) ◽  
pp. 5085-5096 ◽  
Author(s):  
YVES BRIHAYE ◽  
EUGEN RADU ◽  
D. H. TCHRAKIAN

Solutions to EYM systems in five space–time dimensions possessing no gravity decoupling limits, feature a peculiar critical behavior which is absent in their six-, seven- and eight-dimensional counterparts which do possess flat space limits. This critical behavior in five dimensions persists even when a scalar matter field is added, rendering the model nontrivial in the gravity decoupling limit. To this end, both regular and black hole spherically symmetric solutions to the higher curvature EYM–Grassmannian sigma model in d=5 space–time dimensions are constructed. A study of the solutions to the Grassmannian model in flat space is also carried out.


2010 ◽  
Vol 88 (3) ◽  
pp. 189-200 ◽  
Author(s):  
Junji Jia

We study classical solutions in the SU(2) Einstein–Yang–Mills–Higgs theory. The spherically symmetric ansatz for all fields are given, and the equations of motion are derived as a system of ordinary differential equations. The asymptotics and the boundary conditions at the space origin for regular solutions and at the event horizon for black hole solutions are studied. Using the shooting method, we found numerical solutions to the theory. For regular solutions, we find two new sets of asymptotically flat solutions. Each of these sets contains continua of solutions in the parameter space spanned by the shooting parameters. The solutions bifurcate along these parameter curves, and the bifurcations are argued to be due to the internal structure of the model. Both sets of the solutions are asymptotically flat, but one is exponentially so and the other is so with oscillations. For black holes, a new set of boundary conditions is studied, and it is found that there also exists a continuum of black hole solutions in parameter space and similar bifurcation behavior is also present to these solutions. The SU(2) charges of these solutions are found to be zero, and these solutions are proven to be unstable.


1998 ◽  
pp. 55-59 ◽  
Author(s):  
C. Blaga ◽  
P.A. Blaga

In this paper we shall investigate the timelike geodesics for an extremal, spherically symmetric, massless dilaton black hole, using an exact solution obtained by Gary Horowitz.


1994 ◽  
Vol 09 (40) ◽  
pp. 3731-3739 ◽  
Author(s):  
GEORGE LAVRELASHVILI

We discuss the properties and interpretation of a discrete sequence of a static spherically symmetric solutions of the Yang-Mills dilaton theory. This sequence is parametrized by the number of zeros, n, of a component of the gauge field potential. It is demonstrated that solutions with odd n possess all the properties of the sphaleron. It is shown that there are normalizable fermion zero modes in the background of these solutions. The question of instability is critically analyzed.


2015 ◽  
Vol 47 (2) ◽  
Author(s):  
Ming Zhang ◽  
Zhan-Ying Yang ◽  
De-Cheng Zou ◽  
Wei Xu ◽  
Rui-Hong Yue
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