9 research outputs found
Spinning gauged boson stars in anti-de Sitter spacetime
We study axially symmetric solutions of the Einstein-Maxwell-Klein-Gordon
equations describing spinning gauged boson stars in a 3+1 dimensional
asymptotically AdS spacetime. These smooth horizonless solutions possess an
electric charge and a magnetic dipole moment, their angular momentum being
proportional to the electric charge. A special class of solutions with a
self-interacting scalar field, corresponding to static axially symmetric
solitons with a nonzero magnetic dipole moment, is also investigated.Comment: 15 pages, 4 figure
Non-Abelian fields in AdS spacetime: axially symmetric, composite configurations
We construct new finite energy regular solutions in Einstein-Yang-Mills-SU(2)
theory. They are static, axially symmetric and approach at infinity the anti-de
Sitter spacetime background. These configurations are characterized by a pair
of integers , where is related to the polar angle and to the
azimuthal angle, being related to the known flat space monopole-antimonopole
chains and vortex rings. Generically, they describe composite configurations
with several individual components, possesing a nonzero magnetic charge, even
in the absence of a Higgs field. Such Yang-Mills configurations exist already
in the probe limit, the AdS geometry supplying the attractive force needed to
balance the repulsive force of Yang-Mills gauge interactions. The gravitating
solutions are constructed by numerically solving the elliptic
Einstein-DeTurck--Yang-Mills equations. The variation of the gravitational
coupling constant reveals the existence of two branches of gravitating
solutions which bifurcate at some critical value of . The lower energy
branch connects to the solutions in the global AdS spacetime, while the upper
branch is linked to the generalized Bartnik-McKinnon solutions in
asymptotically flat spacetime. Also, a spherically symmetric, closed form
solution is found as a perturbation around the globally anti-de Sitter vacuum
state.Comment: 30 pages, 15 figure
Static black holes with axial symmetry in asymptotically AdS(4) spacetime
The known static electrovacuum black holes in a globally AdS(4) background have an event horizon which is geometrically a round sphere. In this work we argue that the situation is different in models with matter fields possessing an explicit dependence on the azimuthal angle phi, which, however, does not manifest at the level of the energy-momentum tensor. As a result, the full solutions are axially symmetric only, possessing a single (timelike) Killing vector field. Explicit examples of such static black holes are constructed in Einstein-(complex) scalar field and Einstein-Yang-Mills theories. The basic properties of these solutions are discussed, looking for generic features. For example, we notice that the horizon has an oblate spheroidal shape for solutions with a scalar field and a prolate one for black holes with Yang-Mills fields. The deviation from sphericity of the horizon geometry manifests itself in the holographic stress tensor. Finally, based on the results obtained in the probe limit, we conjecture the existence in Einstein-Maxwell theory of static black holes with axial symmetry only
Axially symmetric Yang-Mills-Higgs solutions in AdS spacetime
We consider axially symmetric solutions of SU(2) Yang-Mills-Higgs theory in
globally AdS spacetime and a fixed Schwarzschild-AdS black hole background. The
solutions are characterized by two integers where is related to the
polar angle and to the azimuthal angle. Two types of finite energy, regular
configurations are considered: solutions with net magnetic charge and
monopole-antimonopole pairs and chains with zero net magnetic charge. The
configurations are endowed with an electric charge and carry also a
nonvanishing angular momentum density.Comment: 13 pages, 3 figure
Thermodynamic properties of asymptotically anti-de Sitter black holes in d=4 Einstein-Yang-Mills theory
We investigate the thermodynamics of spherically symmetric black hole solutions in a four-dimensional Einstein-Yang-Mills-SU(2) theory with a negative cosmological constant. Special attention is paid to configurations with a unit magnetic charge. We find that a set of Reissner-Nordstrom-Anti-de Sitter black holes can become unstable to forming non-Abelian hair. However, the hairy black holes are never thermodynamically favoured over the full set of abelian monopole solutions. The thermodynamics of the generic configurations possessing a noninteger magnetic charge is also discussed. (C) 2015 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY license
Test of the Gravitational Redshift with Galileo Satellites in an Eccentric Orbit
On August 22, 2014, the satellites GSAT-0201 and GSAT-0202 of the European GNSS Galileo were unintentionally launched into eccentric orbits. Unexpectedly, this has become a fortunate scientific opportunity since the onboard hydrogen masers allow for a sensitive test of the redshift predicted by the theory of general relativity. In the present Letter, we describe an analysis of approximately three years of data from these satellites including three different clocks. For one of these, we determine the test parameter quantifying a potential violation of the combined effects of the gravitational redshift and the relativistic Doppler shift. The uncertainty of our result is reduced by more than a factor 4 as compared to the values of Gravity Probe A obtained in 1976