1,189 research outputs found
Chaotic motion in multi-black hole spacetimes and holographic screens
We investigate the geodesic motion in dimensional Majumdar-Papapetrou
multi-black hole spacetimes and find that the qualitative features of the D=4
case are shared by the higher dimensional configurations. The motion of
timelike and null particles is chaotic, the phase space being divided into
basins of attraction which are separated by a fractal boundary, with a fractal
dimension . The mapping of the geodesic trajectories on a screen placed in
the asymptotic region is also investigated. We find that the fractal properties
of the phase space induces a fractal structure on the holographic screen, with
a fractal dimension .Comment: 8 pages, 5 figure
Deformed vortices in (4+1)-dimensional Einstein-Yang-Mills theory
We study vortex-type solutions in a (4+1)-dimensional
Einstein-Yang-Mills-SU(2) model. Assuming all fields to be independent on the
extra coordinate, these solutions correspond in a four dimensional picture to
axially symmetric multimonopoles, respectively monopole-antimonopole solutions.
By boosting the five dimensional purely magnetic solutions we find new
configurations which in four dimensions represents rotating regular nonabelian
solutions with an additional electric charge.Comment: 11 pages, including 5 eps files; reference added, discussion
extended; typos correcte
Spherically symmetric selfdual Yang-Mills instantons on curved backgrounds in all even dimensions
We present several different classes of selfdual Yang-Mills instantons in all
even d backgrounds with Euclidean signature. In d=4p+2 the only solutions we
found are on constant curvature dS and AdS backgrounds, and are evaluated in
closed form. In d=4p an interesting class of instantons are given on black hole
backgrounds. One class of solutions are (Euclidean) time-independent and
spherically symmetric in d-1 dimensions, and the other class are spherically
symmetric in all d dimensions. Some of the solutions in the former class are
evaluated numerically, all the rest being given in closed form. Analytic proofs
of existence covering all numerically evaluated solutions are given. All
instantons studied have finite action and vanishing energy momentum tensor and
do not disturb the geometry.Comment: 41 pages, 3 figure
Magnetic charge, angular momentum and negative cosmological constant
We argue that there are no axially symmetric rotating monopole solutions for
a Yang-Mills-Higgs theory in flat spacetime background. We construct axially
symmetric Yang-Mills-Higgs solutions in the presence of a negative cosmological
constant, carrying magnetic charge and a nonvanishing electric charge.
However, these solution are also nonrotating.Comment: 17 pages, LaTeX, 7 figure
Nonabelian solutions in AdS_4 and d=11 supergravity
We consider solutions of the four dimensional Einstein-Yang-Mills system with
a negative cosmological constant , where is the nonabelian
gauge coupling constant. This theory corresponds to a consistent truncation of
gauged supergravity and may be uplifted to supergravity. A
systematic study of all known solutions is presented as well as new
configurations corresponding to rotating regular dyons and rotating nonabelian
black holes. The thermodynamics of the static black hole solutions is also
discussed. The generic EYM solutions present a nonvanishing magnetic flux at
infinity and should give us information about the structure of a CFT in a
background SU(2) field. We argue that the existence of these configurations
violating the no hair conjecture is puzzling from the AdS/CFT point of view.Comment: 52 pages; 24 figures; v2: minor changes, references added, version to
be published in PR
Nonabelian solutions in N=4, D=5 gauged supergravity
We consider static, nonabelian solutions in N=4, D=5 Romans' gauged
supergravity model. Numerical arguments are presented for the existence of
asymptotically anti-de Sitter configurations in the version of the
theory, with a dilaton potential presenting a stationary point. Considering the
version of the theory with a Liouville dilaton potential, we look for
configurations with unusual topology. A new exact solution is presented, and a
counterterm method is proposed to compute the mass and action.Comment: 15 pages, 4 figure
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