941 research outputs found
Gravitational wave detectors
The existence of gravitational radiation is a prediction of Einstein's general theory of relativity. Gravitational waves are perturbations in the curvature of spacetime caused by accelerated masses. Since the 1960s gravitational wave detectors have been built and constantly improved. The present-day generation of resonant mass antennas and laser interferometers has reached the necessary sensitivity to detect gravitational waves from sources in the Milky Way. Within a few years, the next generation of detectors will open the field of gravitational wave astronomy. © IOP Publishing Ltd and Deutsche Physikalische Gesellschaft
The Red Sea Rangers: a case study of using spatial collections and remote sensing to protect aquatic resources
pp. 113-13
Broadband squeezing of quantum noise in a Michelson interferometer with Twin-Signal-Recycling
Twin-Signal-Recycling (TSR) builds on the resonance doublet of two optically
coupled cavities and efficiently enhances the sensitivity of an interferometer
at a dedicated signal frequency. We report on the first experimental
realization of a Twin-Signal-Recycling Michelson interferometer and also its
broadband enhancement by squeezed light injection. The complete setup was
stably locked and a broadband quantum noise reduction of the interferometers
shot noise by a factor of up to 4\,dB was demonstrated. The system was
characterized by measuring its quantum noise spectra for several tunings of the
TSR cavities. We found good agreement between the experimental results and
numerical simulations
Geological setting as an important factor in mangrove plantation site selection in the Red Sea
pp. 107-12
Ein Horchposten ins Universum
Erst seit wenigen Jahren ist es möglich, Gravitationswellen nachzuweisen. Ein neu entwickelter Gravitationswellendetektor zeichnet sich durch besondere Empfindlichkeit aus. Mit seiner Hilfe lassen sich wichtige Informationen über Schwarze Löcher, dunkle Materie und den Ursprung des Alls gewinne
Hartree-Fock-Bogoliubov calculation of charge radii of Sn, Ba, Yb, and Pb isotopes
Charge radii of Sn, Ba, Yb, and Pb isotopes are calculated within
Hartree-Fock-Bogoliubov theory with a Skyrme force and a density-dependent
delta-force pairing. We investigate mean field effects of the pairing upon
odd-even staggering of isotope shifts. HFB equations are solved in the
canonical basis. Odd nuclei are treated in the blocking approximation.Comment: 10 pages including 20 postscript figures, to be published in Nuclear
Physics
Search for Gravitational Waves Associated with Gamma-Ray Bursts during the First Advanced LIGO Observing Run and Implications for the Origin of GRB 150906B
We present the results of the search for gravitational waves (GWs) associated with γ-ray bursts detected during the first observing run of the Advanced Laser Interferometer Gravitational-Wave Observatory (LIGO). We find no evidence of a GW signal for any of the 41 γ-ray bursts for which LIGO data are available with sufficient duration. For all γ-ray bursts, we place lower bounds on the distance to the source using the optimistic assumption that GWs with an energy of were emitted within the – Hz band, and we find a median 90% confidence limit of 71 Mpc at 150 Hz. For the subset of 19 short/hard γ-ray bursts, we place lower bounds on distance with a median 90% confidence limit of 90 Mpc for binary neutron star (BNS) coalescences, and 150 and 139 Mpc for neutron star–black hole coalescences with spins aligned to the orbital angular momentum and in a generic configuration, respectively. These are the highest distance limits ever achieved by GW searches. We also discuss in detail the results of the search for GWs associated with GRB 150906B, an event that was localized by the InterPlanetary Network near the local galaxy NGC 3313, which is at a luminosity distance of Mpc (z = 0.0124). Assuming the γ-ray emission is beamed with a jet half-opening angle , we exclude a BNS and a neutron star–black hole in NGC 3313 as the progenitor of this event with confidence >99%. Further, we exclude such progenitors up to a distance of 102 Mpc and 170 Mpc, respectively.United States National Science Foundation (NSF)Science and Technology Facilities Council (STFC) of the United KingdomMax-Planck-Society (MPS)State of NiedersachsenAustralian Research CouncilItalian Istituto Nazionale di Fisica Nucleare (INFN)French Centre National de la Recherche Scientifique (CNRS)Netherlands Organisation for Scientific ResearchCouncil of Scientific and Industrial Research of IndiaScience & Engineering Research Board (SERB), IndiaMinistry of Human Resource Development, IndiaSpanish Ministerio de EconomÃa y CompetitividadConselleria d’Economia i CompetitivitatConselleria d’Educació Cultura i Universitats of the Govern de les Illes BalearsNational Science Centre of PolandEuropean CommissionRoyal SocietyScottish Funding CouncilScottish Universities Physics AllianceHungarian Scientific Research Fund (OTKA)Lyon Institute of Origins (LIO)National Research Foundation of KoreaIndustry CanadaProvince of OntarioBrazilian Ministry of ScienceFundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Russian Foundation for Basic ResearchLeverhulme TrustMinistry of Science and Technology (MOST)Kavli FoundationNASA/NNX15AU74GRFBR/15-02-00532-iRFBR/16-29-13009-ofi-
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