1,990 research outputs found

    The Dark Energy Survey: Cosmology Results With ~1500 New High-redshift Type Ia Supernovae Using The Full 5-year Dataset

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    International audienceWe present cosmological constraints from the sample of Type Ia supernovae (SN Ia) discovered during the full five years of the Dark Energy Survey (DES) Supernova Program. In contrast to most previous cosmological samples, in which SN are classified based on their spectra, we classify the DES SNe using a machine learning algorithm applied to their light curves in four photometric bands. Spectroscopic redshifts are acquired from a dedicated follow-up survey of the host galaxies. After accounting for the likelihood of each SN being a SN Ia, we find 1635 DES SN in the redshift range 0.100.50.100.5 SNe compared to the previous leading compilation of Pantheon+, and results in the tightest cosmological constraints achieved by any SN data set to date. To derive cosmological constraints we combine the DES supernova data with a high-quality external low-redshift sample consisting of 194 SNe Ia spanning 0.025<z<0.100.025<z<0.10. Using SN data alone and including systematic uncertainties we find ΩM=0.352±0.017\Omega_{\rm M}=0.352\pm 0.017 in a flat Λ\LambdaCDM model, and (ΩM,w)=(0.2640.096+0.074,0.800.16+0.14)(\Omega_{\rm M},w)=(0.264^{+0.074}_{-0.096},-0.80^{+0.14}_{-0.16}) in a flat wwCDM model. For a flat w0waw_0w_aCDM model, we find (ΩM,w0,wa)=(0.4950.043+0.033,0.360.30+0.36,8.84.5+3.7)(\Omega_{\rm M},w_0,w_a)=(0.495^{+0.033}_{-0.043},-0.36^{+0.36}_{-0.30},-8.8^{+3.7}_{-4.5}), consistent with a constant equation of state to within 2σ\sim2 \sigma. Including Planck CMB data, SDSS BAO data, and DES 3×23\times2-point data gives (ΩM,w)=(0.321±0.007,0.941±0.026)(\Omega_{\rm M},w)=(0.321\pm0.007,-0.941\pm0.026). In all cases dark energy is consistent with a cosmological constant to within 2σ\sim2\sigma. In our analysis, systematic errors on cosmological parameters are subdominant compared to statistical errors; these results thus pave the way for future photometrically classified supernova analyses

    The Dark Energy Survey: Cosmology Results With ~1500 New High-redshift Type Ia Supernovae Using The Full 5-year Dataset

    No full text
    International audienceWe present cosmological constraints from the sample of Type Ia supernovae (SN Ia) discovered during the full five years of the Dark Energy Survey (DES) Supernova Program. In contrast to most previous cosmological samples, in which SN are classified based on their spectra, we classify the DES SNe using a machine learning algorithm applied to their light curves in four photometric bands. Spectroscopic redshifts are acquired from a dedicated follow-up survey of the host galaxies. After accounting for the likelihood of each SN being a SN Ia, we find 1635 DES SN in the redshift range 0.100.50.100.5 SNe compared to the previous leading compilation of Pantheon+, and results in the tightest cosmological constraints achieved by any SN data set to date. To derive cosmological constraints we combine the DES supernova data with a high-quality external low-redshift sample consisting of 194 SNe Ia spanning 0.025<z<0.100.025<z<0.10. Using SN data alone and including systematic uncertainties we find ΩM=0.352±0.017\Omega_{\rm M}=0.352\pm 0.017 in a flat Λ\LambdaCDM model, and (ΩM,w)=(0.2640.096+0.074,0.800.16+0.14)(\Omega_{\rm M},w)=(0.264^{+0.074}_{-0.096},-0.80^{+0.14}_{-0.16}) in a flat wwCDM model. For a flat w0waw_0w_aCDM model, we find (ΩM,w0,wa)=(0.4950.043+0.033,0.360.30+0.36,8.84.5+3.7)(\Omega_{\rm M},w_0,w_a)=(0.495^{+0.033}_{-0.043},-0.36^{+0.36}_{-0.30},-8.8^{+3.7}_{-4.5}), consistent with a constant equation of state to within 2σ\sim2 \sigma. Including Planck CMB data, SDSS BAO data, and DES 3×23\times2-point data gives (ΩM,w)=(0.321±0.007,0.941±0.026)(\Omega_{\rm M},w)=(0.321\pm0.007,-0.941\pm0.026). In all cases dark energy is consistent with a cosmological constant to within 2σ\sim2\sigma. In our analysis, systematic errors on cosmological parameters are subdominant compared to statistical errors; these results thus pave the way for future photometrically classified supernova analyses

    The Dark Energy Survey Supernova Program: Cosmological Analysis and Systematic Uncertainties

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    International audienceWe present the full Hubble diagram of photometrically-classified Type Ia supernovae (SNe Ia) from the Dark Energy Survey supernova program (DES-SN). DES-SN discovered more than 20,000 SN candidates and obtained spectroscopic redshifts of 7,000 host galaxies. Based on the light-curve quality, we select 1635 photometrically-identified SNe Ia with spectroscopic redshift 0.100.50.5 supernovae by a factor of five. In a companion paper, we present cosmological results of the DES-SN sample combined with 194 spectroscopically-classified SNe Ia at low redshift as an anchor for cosmological fits. Here we present extensive modeling of this combined sample and validate the entire analysis pipeline used to derive distances. We show that the statistical and systematic uncertainties on cosmological parameters are σΩM,stat+sysΛCDM=\sigma_{\Omega_M,{\rm stat+sys}}^{\Lambda{\rm CDM}}=0.017 in a flat Λ\LambdaCDM model, and (σΩM,σw)stat+syswCDM=(\sigma_{\Omega_M},\sigma_w)_{\rm stat+sys}^{w{\rm CDM}}=(0.082, 0.152) in a flat wwCDM model. Combining the DES SN data with the highly complementary CMB measurements by Planck Collaboration (2020) reduces uncertainties on cosmological parameters by a factor of 4. In all cases, statistical uncertainties dominate over systematics. We show that uncertainties due to photometric classification make up less than 10% of the total systematic uncertainty budget. This result sets the stage for the next generation of SN cosmology surveys such as the Vera C. Rubin Observatory's Legacy Survey of Space and Time

    The Dark Energy Survey Supernova Program: Cosmological Analysis and Systematic Uncertainties

    No full text
    International audienceWe present the full Hubble diagram of photometrically-classified Type Ia supernovae (SNe Ia) from the Dark Energy Survey supernova program (DES-SN). DES-SN discovered more than 20,000 SN candidates and obtained spectroscopic redshifts of 7,000 host galaxies. Based on the light-curve quality, we select 1635 photometrically-identified SNe Ia with spectroscopic redshift 0.100.50.5 supernovae by a factor of five. In a companion paper, we present cosmological results of the DES-SN sample combined with 194 spectroscopically-classified SNe Ia at low redshift as an anchor for cosmological fits. Here we present extensive modeling of this combined sample and validate the entire analysis pipeline used to derive distances. We show that the statistical and systematic uncertainties on cosmological parameters are σΩM,stat+sysΛCDM=\sigma_{\Omega_M,{\rm stat+sys}}^{\Lambda{\rm CDM}}=0.017 in a flat Λ\LambdaCDM model, and (σΩM,σw)stat+syswCDM=(\sigma_{\Omega_M},\sigma_w)_{\rm stat+sys}^{w{\rm CDM}}=(0.082, 0.152) in a flat wwCDM model. Combining the DES SN data with the highly complementary CMB measurements by Planck Collaboration (2020) reduces uncertainties on cosmological parameters by a factor of 4. In all cases, statistical uncertainties dominate over systematics. We show that uncertainties due to photometric classification make up less than 10% of the total systematic uncertainty budget. This result sets the stage for the next generation of SN cosmology surveys such as the Vera C. Rubin Observatory's Legacy Survey of Space and Time

    Gene Therapy to Treat Osteopenia Associated With Chronic Ethanol Consumption and Aldehyde Dehydrogenase 2 Deficiency

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    ABSTRACT Aldehyde dehydrogenase 2 (ALDH2) deficiency affects 35% to 45% of East Asians and 8% of the world population. ALDH2 is the second enzyme in the ethanol metabolism pathway. The common genetic variant ALDH2*2 allele has a glutamic acid‐to‐lysine substitution at position 487 (E487K) that reduces the enzyme activity, resulting in an accumulation of acetaldehyde after ethanol consumption. The ALDH2*2 allele is associated with increased risk of osteoporosis and hip fracture. Our prior study showed that administration of an adeno‐associated virus (AAV) serotype rh.10 gene transfer vector expressing the human ALDH2 cDNA (AAVrh.10hALDH2) before initiation of ethanol consumption prevented bone loss in ALDH2‐deficient homozygous knockin mice carrying the E487K mutation (Aldh2E487K+/+). We hypothesized that AAVrh.10hALDH2 administration after establishment of osteopenia would be able to reverse bone loss due to ALDH2 deficiency and chronic ethanol consumption. To test this hypothesis, male and female Aldh2E487K+/+ mice (n = 6) were given ethanol in the drinking water for 6 weeks to establish osteopenia and then administered AAVrh.10hALDH2 (1011 genome copies). Mice were evaluated for an additional 12 weeks. AAVrh.10hALDH2 administration after osteopenia was established corrected weight loss and locomotion phenotypes and, importantly, increased midshaft femur cortical bone thickness, the most important component of bone in the resistance to fractures, and showed a trend toward increased trabecular bone volume. AAVrh.10hALDH2 is a promising therapeutic for osteoporosis in ALDH2‐deficient individuals. © 2023 The Authors. JBMR Plus published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research

    La prova privilegiata «sbiadita» e le ambizioni frustrate del contraente a valle.Spunti per una presunzione legale iuris tantum

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    L'A. esamina criticamente l'orientamente recentemente emerso in giurisprudenza e da ultimo confermato dal Collegio di Coordinaento ABF, secondo cui l'accertamento della violazione concorrenziale, condotto dall'Autorità antimonopolistica competente e cristallizzato in provvedimento divenuto definitivo, non potrebbe comunque valere quale prova privilegiata in relazione a fattispecie contrattuali perfezionate successivamente alla sua emanazione. Nel rilevarne la contraddittorietà con l'interpretazione avallata dalle Sezioni Unite della Cassazione, che vuole i contratti di fideiussione omnibus, a valle di NBU, fulminati da nullità paziale, l'A. argomenta invece l'esistenza nel sistema di una presunzione legale iuris tantum circa l'esistenza della violazione già accertata

    First Double-Differential Measurement of Kinematic Imbalance in Neutrino Interactions with the MicroBooNE Detector

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    We report the first measurement of flux-integrated double-differential quasielasticlike neutrino-argon cross sections, which have been made using the Booster Neutrino Beam and the MicroBooNE detector at Fermi National Accelerator Laboratory. The data are presented as a function of kinematic imbalance variables which are sensitive to nuclear ground-state distributions and hadronic reinteraction processes. We find that the measured cross sections in different phase-space regions are sensitive to different nuclear effects. Therefore, they enable the impact of specific nuclear effects on the neutrino-nucleus interaction to be isolated more completely than was possible using previous single-differential cross section measurements. Our results provide precision data to help test and improve neutrino-nucleus interaction models. They further support ongoing neutrino-oscillation studies by establishing phase-space regions where precise reaction modeling has already been achieved

    First demonstration of O (1 ns) timing resolution in the MicroBooNE liquid argon time projection chamber

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    MicroBooNE is a neutrino experiment located in the Booster Neutrino Beamline (BNB) at Fermilab, which collected data from 2015 to 2021. MicroBooNE's liquid argon time projection chamber (LArTPC) is accompanied by a photon detection system consisting of 32 photomultiplier tubes used to measure the argon scintillation light and determine the timing of neutrino interactions. Analysis techniques combining light signals and reconstructed tracks are applied to achieve a neutrino interaction time resolution of O(1 ns). The result obtained allows MicroBooNE to access the nanosecond beam structure of the BNB for the first time. The timing resolution achieved will enable significant enhancement of cosmic background rejection for all neutrino analyses. Furthermore, the ns timing resolution opens new avenues to search for long-lived-particles such as heavy neutral leptons in MicroBooNE, as well as in future large LArTPC experiments, namely the SBN program and DUNE

    First constraints on light sterile neutrino oscillations from combined appearance and disappearance searches with the MicroBooNE detector

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    We present a search for eV-scale sterile neutrino oscillations in the MicroBooNE liquid argon detector, simultaneously considering all possible appearance and disappearance effects within the 3+1 active-to-sterile neutrino oscillation framework. We analyze the neutrino candidate events for the recent measurements of charged-current ν_{e} and ν_{μ} interactions in the MicroBooNE detector, using data corresponding to an exposure of 6.37×10^{20} protons on target from the Fermilab booster neutrino beam. We observe no evidence of light sterile neutrino oscillations and derive exclusion contours at the 95% confidence level in the plane of the mass-squared splitting Δm_{41}^{2} and the sterile neutrino mixing angles θ_{μe} and θ_{ee}, excluding part of the parameter space allowed by experimental anomalies. Cancellation of ν_{e} appearance and ν_{e} disappearance effects due to the full 3+1 treatment of the analysis leads to a degeneracy when determining the oscillation parameters, which is discussed in this Letter and will be addressed by future analyses
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