62 research outputs found

    Comment on the new AdS universe

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    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

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    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

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    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 116^{116}CdWO4_4 scintillating bolometer for neutrinoless double-beta-decay searches

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    For the first time, a cadmium tungstate crystal scintillator enriched in 116^{116}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 γ\gamma 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

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    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

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    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

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    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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