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Open Data from LIGO, Virgo, and KAGRA through the First Part of the Fourth Observing Run
No full textInternational audienceLIGO, Virgo, and KAGRA form a network of gravitational-wave observatories. Data and analysis results from this network are made publicly available through the Gravitational Wave Open Science Center. This paper describes open data from this network, including the addition of data from the first part of the fourth observing run (O4a) and selected periods from the preceding engineering run, collected from May 2023 to January 2024. The public data set includes calibrated strain time series for each instrument, data from additional channels used for noise subtraction and detector characterization, and analysis data products from version 4.0 of the Gravitational-Wave Transient Catalog
Association between physical activity with disease activity and functional disability in patients with inflammatory bowel disease
No full textInternational audienceBackground and aims: The impact of Physical activity (PA) on the activity of inflammatory bowel disease (IBD) remains unclear.Patients and methods: A descriptive cross-sectional study included consecutive patients with Crohn's disease (CD), ulcerative colitis (UC). PA was assessed using the short International Physical Activity Questionnaire. PA was classified as low, medium or high PA. PA was also assessed according to WHO recommendations. IBD activity was evaluated using PRO-2, while IBD-related disability was assessed with the IBD-disk questionnaire.Results: Among a total of 2514 patients (1715 CD), only 28.8% met the WHO recommendations on PA (49.8% had low PA, 35.2% had medium PA, and 15.0% had high PA). Medium and high PA levels were associated with a higher rate of patient-reported clinical remission in patients with CD (OR 1.30 [1.08-1.57] for medium PA, and 1.33 [1.03-1.72] for high PA vs. low PA; p-trend=0.02) but not in those with UC. Higher PA levels were associated with less IBD-related disability in both CD, and UC.Conclusion: In a large cohort of IBD patients, moderate and high PA was associated with higher rates of clinical remission in patients with CD and lower IBD-related disability in both CD and UC patients
GWTC-4.0: Constraints on the Cosmic Expansion Rate and Modified Gravitational-wave Propagation
No full textInternational audienceWe analyze data from 142 of the 218 gravitational-wave (GW) sources in the fourth LIGO-Virgo-KAGRA Collaboration (LVK) Gravitational-Wave Transient Catalog (GWTC-4.0) to estimate the Hubble constant jointly with the population properties of merging compact binaries. We measure the luminosity distance and redshifted masses of GW sources directly; in contrast, we infer GW source redshifts statistically through i) location of features in the compact object mass spectrum and merger rate evolution, and ii) identifying potential host galaxies in the GW localization volume. Probing the relationship between source luminosity distances and redshifts obtained in this way yields constraints on cosmological parameters. We also constrain parameterized deviations from general relativity which affect GW propagation, specifically those modifying the dependence of a GW signal on the source luminosity distance. Assuming our fiducial model for the source-frame mass distribution and using GW candidates detected up to the end of the fourth observing run (O4a), together with the GLADE+ all-sky galaxy catalog, we estimate km s Mpc. This value is reported as a median with 68.3% (90%) symmetric credible interval, and includes combination with the measurement from GW170817 and its electromagnetic counterpart. Using a parametrization of modified GW propagation in terms of the magnitude parameter , we estimate , where recovers the behavior of general relativity
Rethinking glacial cirque evolution: interglacial sediment contributions in Quaternary cirque widening, Westfjords, Iceland
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GWTC-4.0: Population Properties of Merging Compact Binaries
No full textInternational audienceWe detail the population properties of merging compact objects using 158 mergers from the cumulative Gravitational-Wave Transient Catalog 4.0, which includes three types of binary mergers: binary neutron star, neutron star--black hole binary, and binary black hole mergers. We resolve multiple over- and under-densities in the black hole mass distribution: features persist at primary masses of and with a possible third feature at . These are departures from an otherwise power-law-like continuum that steepens above . Binary black holes with primary masses near are more likely to have less massive secondaries, with a mass ratio distribution peaking at , potentially a signature of stable mass transfer during binary evolution. Black hole spins are inferred to be non-extremal, with 90% of black holes having , and preferentially aligned with binary orbits, implying many merging binaries form in isolation. However, we find a significant fraction, 0.24-0.42, of binaries have negative effective inspiral spins, suggesting many could be formed dynamically in gas-free environments. We find evidence for correlation between effective inspiral spin and mass ratio, though it is unclear if this is driven by variation in the mode of the distribution or the width. (Abridged
Updated Bounds on the Minimal Left-Right Symmetric Model from LHC Dilepton Resonance Searches
No full textInternational audienceThe Left-Right model is a popular extension of the Standard Model that features three new neutral gauge bosons, and . Collider searches for a Left-Right symmetry are often concentrated on the charged right-handed current, but in this work, we take advantage of the dilepton data at the LHC with center-of-mass energy of 13 TeV and 139 fb of integrated luminosity to place lower mass bounds in the mass based on the process. We vary the gauge coupling from to , and impose TeV and TeV, respectively. Lastly, we put our findings into perspective with searches at the LHC and show that our limits cover an unexplored region of parameter space, where the right-handed neutrino is heavier than the boson
What We Can Learn From the Sensor-to-Plasma Coupling Resistance Measurements in the Earth Ionosphere
No full textInternational audienceMeasurements of electric potentials and currents in the Earth’s ionosphere are primarily influenced by the thermal plasma properties and the intensity of photoelectron emission from sunlit spacecraft surfaces. These measurements can be significantly affected by a plasma sheath that forms around the satellite to neutralize surface electric charging in contact with the ambient plasma. In the ionosphere, this sheath typically ranges from a few to several tens of centimeters in thickness and contains plasma that slightly differ from the surrounding undisturbed environment. Therefore, accurately characterizing the electrical properties of the sheath is essential for reliable data interpretation. In this study, we analyze ion plasma and electric field measurements taken at an altitude of 700 km by the Centre National d’Etudes Spatiales (CNES) detection of electro-magnetic emissions transmitted from earthquake region (DEMETER) microsatellite. The data were collected during specific orbital passes when onboard instruments operated in calibration mode. During these sequences, electric currents were intentionally injected from the electric field sensors into the surrounding plasma, enabling estimation of the sensor-to-plasma coupling resistance across the sheath. Plasma parameters obtained by fitting the resistance–current curve with a standard orbital-motion-limited (OML) model are compared with those derived from the ion instrument on the same spacecraft. The dataset confirms the consistency of plasma measurements performed by the two instruments
To what extent are the IASI water vapour profiles representative of the conditions in the autumn before the HPE? Lessons learned from the WaLiNeAs campaign
No full textInternational audienceThe WaLiNeAs campaign took place along the north-western Mediterranean coast between October 2022 and January 2023. This period was marked by unusual weather conditions associated with dry autumn and winter. In such conditions and for the first time, eight ground-based stations equipped with water vapour Raman lidars were strategically deployed by four European countries. We studied the consistency of this network with the water vapour mixing ratio (WVMR) products derived from the Infrared Atmospheric Sounding Interferometer (IASI) and the European Centre for Medium-Range Weather Forecasts (ECMWF) Reanalysis (ERA5), which assimilate IASI radiances. The statistical metrics used in the comparison are the mean bias (MB, defined as lidar -IASI or ERA5), the root mean square error (RMSE) and the correlation coefficient (COR). A positive MB of approximately 0.9 g kg -1 (respectively 0.6 g kg⁻¹) between 0.2 and 5 km above mean sea level (amsl) indicates a systematic underestimation of the WVMR by IASI (respectively ERA5). RMSE values range from 1 to 2 g kg -1 across all lidar stations for IASI and ERA5, while the measurement uncertainties of the lidars are typically below 0.4 g kg -1 . COR presents little variation between stations, it ranges from 0.7 to 0.8 and remains almost constant between 0.2 and 5 km amsl. Both the IASI and the ERA5 products appear to accurately reproduce the temporal variability of the vertical structure of water vapour in the low troposphere. Nevertheless, they show MB and RMSE significantly above the uncertainties of lidar measurements
Dark Energy Survey Year 6 Results: Galaxy-galaxy lensing
No full textInternational audienceWe present galaxy--galaxy lensing (GGL) measurements from the full six years of data from the Dark Energy Survey (DES Y6), covering and used in the DES Y6 pt cosmological analysis. We use the MagLim++ lens sample, containing million galaxies divided into six redshift bins, and the Metadetection source catalog, including million galaxies divided into four redshift bins. The mean tangential shear signal achieves a total signal-to-noise ratio (S/N) of , corresponding to a improvement over DES Y3. After applying the scale cuts used in the cosmological analysis, with () for the linear (nonlinear) galaxy-bias model, the S/N is reduced to (90). A comprehensive suite of validation tests demonstrates that the measurement is robust against observational and astrophysical systematics at the statistical precision required for the DES Y6 analysis. Although not used in the main cosmological analysis, we extract high--signal-to-noise geometric shear-ratio measurements from the galaxy--galaxy lensing signal on small angular scales. These measurements provide an internal consistency check on the photometric redshift distributions and shear calibration used in the pt analysis
Scaling laws for amplitude surrogates
No full textInternational audienceScaling laws describing the dependence of neural network performance on the amount of training data, the spent compute, and the network size have emerged across a huge variety of machine learning task and datasets. In this work, we systematically investigate these scaling laws in the context of amplitude surrogates for particle physics. We show that the scaling coefficients are connected to the number of external particles of the process. Our results demonstrate that scaling laws are a useful tool to achieve desired precision targets