62 research outputs found
Comment on the new AdS universe
We show that Bonnor's new Anti-de Sitter (AdS) universe and its D-dimensional
generalization is the previously studied AdS soliton.Comment: 2 pages; version 2: major changes including the titl
Static Cylindrical Matter Shells
Static cylindrical shells composed of massive particles arising from matching
of two different Levi-Civita space-times are studied for the shell satisfying
either isotropic or anisotropic equation of state. We find that these solutions
satisfy the energy conditions for certain ranges of the parameters.Comment: 9 pages, 3 figures, Latex; Final version, To appear in General
Relativity and Gravitatio
Notes on static cylindrical shells
Static cylindrical shells made of various types of matter are studied as
sources of the vacuum Levi-Civita metrics. Their internal physical properties
are related to the two essential parameters of the metrics outside. The total
mass per unit length of the cylinders is always less than 1/4. The results are
illustrated by a number of figures.Comment: 14 pages, 8 figure
First test of an enriched CdWO scintillating bolometer for neutrinoless double-beta-decay searches
For the first time, a cadmium tungstate crystal scintillator enriched in
Cd has been succesfully tested as a scintillating bolometer. The
measurement was performed above ground at a temperature of 18 mK. The crystal
mass was 34.5 g and the enrichment level ~82 %. Despite a substantial pile-up
effect due to above-ground operation, the detector demonstrated a high energy
resolution (2-7 keV FWHM in 0.2-2.6 MeV energy range), a powerful
particle identification capability and a high level of internal radiopurity.
These results prove that cadmium tungstate is an extremely promising detector
material for a next-generation neutrinoless double-beta decay bolometric
experiment, like that proposed in the CUPID project (CUORE Upgrade with
Particle IDentification)
Exact Relativistic Static Charged Dust Disks and Non-axisymmetric Structures
The well-known ``displace, cut and reflect'' method used to generate disks
from given solutions of Einstein field equations is applied to the
superposition of twoextreme Reissner-Nordstrom black holes to construct disks
made of charged dust and alsonon-axisymmetric planar distributions of charged
dust on the z=0 plane. They are symmetric with respect to twoor one coordinate
axes, depending whether the black holes have equal or unequal masses,
respectively.For these non-axisymmetric distributions of matter we also study
the effective potential for geodesic motion of neutral test particles.Comment: Classical and Quantum Gravity (in press). 15 pages, LaTex, 8 .eps
fig
Algebraically special axisymmetric solutions of the higher-dimensional vacuum Einstein equation
A d-dimensional spacetime is "axisymmetric" if it possesses an SO(d-2)
isometry group whose orbits are (d-3)-spheres. In this paper, algebraically
special, axisymmetric solutions of the higher dimensional vacuum Einstein
equation (with cosmological constant) are investigated. Necessary and
sufficient conditions for static axisymmetric solutions to belong to different
algebraic classes are presented. Then general (possibly time-dependent)
axisymmetric solutions are discussed. All axisymmetric solutions of algebraic
types II, D, III and N are obtained.Comment: 28 page
Gravitation: following the Prague inspiration : a volume in celebration of the 60th birthday of Jiri Bicak
This volume is dedicated to Jirí Bicák on the occasion of his 60th birthday. The authors are his former students who currently work in the fields of general relativity, astrophysics, theoretical physics and cosmology. Unlike in traditional Festschrifts with many short contributions, they present several comprehensive surveys and elaborate original works. The subjects range from the motion of stars in galactic nuclei to quantum mechanics on a boundary, and include current topics such as cosmological perturbations, effects of a repulsive cosmological constant, discs around black holes and gravi
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