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

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

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

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

Pensar lo social : pluralismo teórico en América Latina

Este libro permite, entre otras cosas, acercarse a la mayor parte de los desarrollos, las tendencias y los intereses teóricos que ocupan actualmente a los cientistas sociales en América Latina. Es un mapa capaz de mostrar mucho de lo que se está haciendo en el campo de la teoría social, y capaz también de mostrar mucho de lo que queda por hacer. Uno de los rasgos más notables de este mapa es su pluralidad. Se constata aquí que las más diversas tradiciones de pensamiento transitan por nuestro continente, y que son reelaboradas por nuevas lecturas de un modo tan vital como riguroso y consistente. Queda por saber si este pluralismo existente se irá todavía ampliando, si llegará a albergar más cabalmente tradiciones no tradicionales de pensamiento. Es decir, si podrá abrirse con más fuerza a un diálogo con puntos de vista sobre lo social, lo político y lo cultural provenientes de las epistemes no occidentales, o no completamente occidentales, que habitan el sur global

Pensar lo social : pluralismo teórico en América Latina

Este libro permite, entre otras cosas, acercarse a la mayor parte de los desarrollos, las tendencias y los intereses teóricos que ocupan actualmente a los cientistas sociales en América Latina. Es un mapa capaz de mostrar mucho de lo que se está haciendo en el campo de la teoría social, y capaz también de mostrar mucho de lo que queda por hacer. Uno de los rasgos más notables de este mapa es su pluralidad. Se constata aquí que las más diversas tradiciones de pensamiento transitan por nuestro continente, y que son reelaboradas por nuevas lecturas de un modo tan vital como riguroso y consistente. Queda por saber si este pluralismo existente se irá todavía ampliando, si llegará a albergar más cabalmente tradiciones no tradicionales de pensamiento. Es decir, si podrá abrirse con más fuerza a un diálogo con puntos de vista sobre lo social, lo político y lo cultural provenientes de las epistemes no occidentales, o no completamente occidentales, que habitan el sur global

Search for intermediate-mass black hole binaries in the third observing run of Advanced LIGO and Advanced Virgo

International audienceIntermediate-mass black holes (IMBHs) span the approximate mass range 100−105 M⊙, between black holes (BHs) that formed by stellar collapse and the supermassive BHs at the centers of galaxies. Mergers of IMBH binaries are the most energetic gravitational-wave sources accessible by the terrestrial detector network. Searches of the first two observing runs of Advanced LIGO and Advanced Virgo did not yield any significant IMBH binary signals. In the third observing run (O3), the increased network sensitivity enabled the detection of GW190521, a signal consistent with a binary merger of mass ∼150 M⊙ providing direct evidence of IMBH formation. Here, we report on a dedicated search of O3 data for further IMBH binary mergers, combining both modeled (matched filter) and model-independent search methods. We find some marginal candidates, but none are sufficiently significant to indicate detection of further IMBH mergers. We quantify the sensitivity of the individual search methods and of the combined search using a suite of IMBH binary signals obtained via numerical relativity, including the effects of spins misaligned with the binary orbital axis, and present the resulting upper limits on astrophysical merger rates. Our most stringent limit is for equal mass and aligned spin BH binary of total mass 200 M⊙ and effective aligned spin 0.8 at 0.056 Gpc−3 yr−1 (90% confidence), a factor of 3.5 more constraining than previous LIGO-Virgo limits. We also update the estimated rate of mergers similar to GW190521 to 0.08 Gpc−3 yr−1.Key words: gravitational waves / stars: black holes / black hole physicsCorresponding author: W. Del Pozzo, e-mail: [email protected]† Deceased, August 2020