8 research outputs found

    Search for eccentric black hole coalescences during the third observing run of LIGO and Virgo

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    Despite the growing number of confident binary black hole coalescences observed through gravitational waves so far, the astrophysical origin of these binaries remains uncertain. Orbital eccentricity is one of the clearest tracers of binary formation channels. Identifying binary eccentricity, however, remains challenging due to the limited availability of gravitational waveforms that include effects of eccentricity. Here, we present observational results for a waveform-independent search sensitive to eccentric black hole coalescences, covering the third observing run (O3) of the LIGO and Virgo detectors. We identified no new high-significance candidates beyond those that were already identified with searches focusing on quasi-circular binaries. We determine the sensitivity of our search to high-mass (total mass M>70 M⊙) binaries covering eccentricities up to 0.3 at 15 Hz orbital frequency, and use this to compare model predictions to search results. Assuming all detections are indeed quasi-circular, for our fiducial population model, we place an upper limit for the merger rate density of high-mass binaries with eccentricities 0<e≤0.3 at 0.33 Gpc−3 yr−1 at 90\% confidence level

    Observation of gravitational waves from the coalescence of a 2.5−4.5 M⊙ compact object and a neutron star

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    Ultralight vector dark matter search using data from the KAGRA O3GK run

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    Among the various candidates for dark matter (DM), ultralight vector DM can be probed by laser interferometric gravitational wave detectors through the measurement of oscillating length changes in the arm cavities. In this context, KAGRA has a unique feature due to differing compositions of its mirrors, enhancing the signal of vector DM in the length change in the auxiliary channels. Here we present the result of a search for U(1)B−L gauge boson DM using the KAGRA data from auxiliary length channels during the first joint observation run together with GEO600. By applying our search pipeline, which takes into account the stochastic nature of ultralight DM, upper bounds on the coupling strength between the U(1)B−L gauge boson and ordinary matter are obtained for a range of DM masses. While our constraints are less stringent than those derived from previous experiments, this study demonstrates the applicability of our method to the lower-mass vector DM search, which is made difficult in this measurement by the short observation time compared to the auto-correlation time scale of DM

    Search for gravitational-lensing signatures in the full third observing run of the LIGO-Virgo network

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    Gravitational lensing by massive objects along the line of sight to the source causes distortions of gravitational wave-signals; such distortions may reveal information about fundamental physics, cosmology and astrophysics. In this work, we have extended the search for lensing signatures to all binary black hole events from the third observing run of the LIGO--Virgo network. We search for repeated signals from strong lensing by 1) performing targeted searches for subthreshold signals, 2) calculating the degree of overlap amongst the intrinsic parameters and sky location of pairs of signals, 3) comparing the similarities of the spectrograms amongst pairs of signals, and 4) performing dual-signal Bayesian analysis that takes into account selection effects and astrophysical knowledge. We also search for distortions to the gravitational waveform caused by 1) frequency-independent phase shifts in strongly lensed images, and 2) frequency-dependent modulation of the amplitude and phase due to point masses. None of these searches yields significant evidence for lensing. Finally, we use the non-detection of gravitational-wave lensing to constrain the lensing rate based on the latest merger-rate estimates and the fraction of dark matter composed of compact objects

    Arteria coronaria descendente anterior doble: reporte de un caso y revisión de la literatura

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    La arteria coronaria descendente anterior es la arteria coronaria con el trayecto más constante; sin embargo en algunas ocasiones puede presentarse un sistema doble. Se reporta y se realiza una revisión de la literatura de un caso de un paciente con arteria coronaria descendente anterior doble tipo 1, con bloqueo de rama izquierda pero sin lesiones ateromatosas significativas

    Implante percutáneo de prótesis aórticas torácicas y abdominales en pacientes de alto riesgo quirúrgico

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    el aneurisma aórtico es frecuente; su ruptura depende del diámetro. La cirugía es el manejo de elección; como alternativa está el implante intraluminal de stents. Objetivo: analizar el impacto del implante percutáneo de los stents aórticos en pacientes de alto riesgo quirúrgico con seguimiento mínimo de un año. Método: estudio descriptivo llevado a cabo desde diciembre de 2005 hasta marzo de 2010, en el que se incluyeron 125 pacientes con aneurisma de aorta torácica o abdominal, criterio quirúrgico por su diámetro y que además fueron rechazados por cirugía dado su alto riesgo. Los desenlaces fueron: muerte intraoperatoria, por cualquier causa y relacionada con el aneurisma a uno, seis y doce meses. Las complicaciones se definieron como las vasculares ocurridas durante los primeros treinta días. Resultados: el aneurisma abdominal fue más frecuente (70,4%). La mortalidad total a un seguimiento de 25,7 meses fue 14,8%; de este porcentaje 5,2% fallecieron por causas relacionadas con el aneurisma. Un paciente falleció durante la intervención. Se reintervinieron 4,3% por fugas. Hubo mayor mortalidad relacionada con el aneurisma en los torácicos (14,7 vs. 1,2% p = 0,003) y tendencia en los de mayor diámetro (6,9 vs. 5,7 cm p = 0,210). No hubo relación entre mortalidad y diabetes mellitus, tabaquismo, enfermedad coronaria, hipertensión arterial o dislipidemia. Conclusiones: la mortalidad relacionada con el aneurisma en pacientes intervenidos con stent graft aórtico es baja. Ésta se asoció a la torácica y al mayor diámetro aneurismático. Las complicaciones no significaron un aumento en mortalidad. En conclusión, en pacientes con aneurisma aórtico y alto riesgo quirúrgico rechazados para cirugía abierta, el abordaje percutáneo es un tratamiento seguro y eficaz a un seguimiento a mediano plazo

    Erratum to: Guidelines for the use and interpretation of assays for monitoring autophagy (3rd edition) (Autophagy, 12, 1, 1-222, 10.1080/15548627.2015.1100356

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    Guidelines for the use and interpretation of assays for monitoring autophagy (3rd edition)

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