196 research outputs found
Fate of Yang-Mills black hole in early Universe
According to the Big Bang Theory as we go back in time the Universe becomes
progressively hotter and denser. This leads us to believe that the early
Universe was filled with hot plasma of elementary particles. Among many
questions concerning this phase of history of the Universe there are questions
of existence and fate of magnetic monopoles and primordial black holes. Static
solution of Einstein-Yang-Mills system may be used as a toy model for such a
black hole. Using methods of field theory we will show that its existence and
regularity depend crucially on the presence of fermions around it.Comment: 4 pages. The following article is to be published in AIP Conference
Proceedings. Conference: "Multiverse and Fundamental Cosmology", Szczecin,
Poland, 10-14 September, 2012. Misprint in bibliography correcte
Dark sector impact on gravitational collapse of an electrically charged scalar field
Dark matter and dark energy are dominating components of the Universe. Their
presence affects the course and results of processes, which are driven by the
gravitational interaction. The objective of the paper was to examine the
influence of the dark sector on the gravitational collapse of an electrically
charged scalar field. A phantom scalar field was used as a model of dark energy
in the system. Dark matter was modeled by a complex scalar field with a quartic
potential, charged under a U(1)-gauge field. The dark components were coupled
to the electrically charged scalar field via the exponential coupling and the
gauge field-Maxwell field kinetic mixing, respectively. Complete non-linear
simulations of the investigated process were performed. They were conducted
from regular initial data to the end state, which was the matter dispersal or a
singularity formation in a spacetime. During the collapse in the presence of
dark energy dynamical wormholes and naked singularities were formed in emerging
spacetimes. The wormhole throats were stabilized by the violation of the null
energy condition, which occurred due to a significant increase of a value of
the phantom scalar field function in its vicinity. The square of mass parameter
of the dark matter scalar field potential controlled the formation of a Cauchy
horizon or wormhole throats in the spacetime. The joint impact of dark energy
and dark matter on the examined process indicated that the former decides what
type of an object forms, while the latter controls the amount of time needed
for the object to form. Additionally, the dark sector suppresses the natural
tendency of an electrically charged scalar field to form a dynamical
Reissner-Nordstr\"om spacetime during the gravitational collapse.Comment: 46 pages, 28 figure
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