The recent discovery by Advanced LIGO and Advanced Virgo of a gravitational wave signal from a binary neutron star inspiral has enabled tests of general relativity (GR) with this new type of source. This source, for the first time, permits tests of strong-field dynamics of compact binaries in the presence of matter. In this Letter, we place constraints on the dipole radiation and possible deviations from GR in the post-Newtonian coefficients that govern the inspiral regime.
View Article and Find Full Text PDFWe analyze the impact of a proposed tidal instability coupling p modes and g modes within neutron stars on GW170817. This nonresonant instability transfers energy from the orbit of the binary to internal modes of the stars, accelerating the gravitational-wave driven inspiral. We model the impact of this instability on the phasing of the gravitational wave signal using three parameters per star: an overall amplitude, a saturation frequency, and a spectral index.
View Article and Find Full Text PDFWe present the first Advanced LIGO and Advanced Virgo search for ultracompact binary systems with component masses between 0.2 M_{⊙}-1.0 M_{⊙} using data taken between September 12, 2015 and January 19, 2016.
View Article and Find Full Text PDFOn 17 August 2017, the LIGO and Virgo observatories made the first direct detection of gravitational waves from the coalescence of a neutron star binary system. The detection of this gravitational-wave signal, GW170817, offers a novel opportunity to directly probe the properties of matter at the extreme conditions found in the interior of these stars. The initial, minimal-assumption analysis of the LIGO and Virgo data placed constraints on the tidal effects of the coalescing bodies, which were then translated to constraints on neutron star radii.
View Article and Find Full Text PDFBackground: Early after neonatal cardiac surgery hemodynamic dysfunction may be evident. However, still is not clear if dysfunction and outcome is related to visible myocardial alterations. The aim of the present study was the histological analysis of myocardial tissue of neonatal piglets after cardiopulmonary bypass (CPB) and cardioplegic arrest.
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