Now showing items 2056-2075 of 10832

    • dadi.CUDA: Accelerating Population Genetics Inference with Graphics Processing Units

      Gutenkunst, Ryan N; Department of Molecular and Cellular Biology, University of Arizona (Oxford University Press, 2021)
      dadi is a popular but computationally intensive program for inferring models of demographic history and natural selection from population genetic data. I show that running dadi on a Graphics Processing Unit can dramatically speed computation compared with the CPU implementation, with minimal user burden. Motivated by this speed increase, I also extended dadi to four- and five-population models. This functionality is available in dadi version 2.1.0, https://bitbucket.org/gutenkunstlab/dadi/. © 2021 The Author(s).
    • DAGLα Inhibition as a Non-invasive and Translational Model of Episodic Headache

      Levine, A.; Liktor-Busa, E.; Karlage, K.L.; Giancotti, L.; Salvemini, D.; Vanderah, T.W.; Largent-Milnes, T.M.; Department of Pharmacology, University of Arizona (Frontiers Media S.A., 2021)
      Recent findings suggested that Clinical Endocannabinoid Deficiency underlies the pathophysiology of pain disorders, including migraine and headache. In models of medication overuse headache induced by sustained administration of sumatriptan or morphine, 2-AG levels were selectively depleted in the periaqueductal gray (PAG) and anandamide (AEA) increased in the cortex suggesting distinct regulation of the endocannabinoid system during headache pain. These results led to the hypothesis that blockade of DAGL, to reduce 2-AG levels would induce headache-like behaviors as a new, translationally relevant model of episodic headache. Our study investigated whether non-selective and selective blockade of DAGL, the main biosynthetic enzyme for 2-AG, induced periorbital and hind-paw allodynia, photophobia, anxiety-like behaviors, responsivity to abortive anti-migraine agents, and 2-AG/AEA levels. Injection of non-selective DAGL (DH376, 10 mg/kg, IP) and selective DAGLα (LEI106, 20 mg/kg, IP) inhibitors, but not DAGLβ agents, induced facial sensitivity in 100% and ∼60% of female and male rats, respectively, without induction of peripheral sensitivity. Notably, male rats showed significantly less sensitivity than female rats after DAGLα inhibition, suggesting sexual dimorphism in this mechanism. Importantly, LEI106 induced periorbital allodynia was attenuated by administration of the clinically available abortive antimigraine agents, sumatriptan and olcegepant. Selective DAGLα inhibition induced significant photophobia as measured by the light-dark box, without anxiety like behaviors or changes in voluntary movement. Analysis of AEA and 2-AG levels at the time of peak pain sensitivity revealed reductions in 2-AG in the visual cortex and periaqueductal gray (PAG), without altering anandamide or significantly increasing diacylglycerol levels. These results provide foundational evidence for DAGL-2AG in the induction of headache-like pain and photophobia without extracephalic allodynia, thus modeling the clinical episodic migraine. Mechanistically, behavioral measures of headache sensitivity after DAGL inhibition suggests that reduced 2-AG signaling in the cortex and PAG, but not the trigeminal nucleus caudalis or trigeminal ganglia, drives headache initiation. Therefore, episodic DAGL inhibition, which reduces the time, cost, and invasiveness of currently accepted models of headache, may fill the need for episodic migraine/headache models mirroring clinical presentation. Moreover, use of this approach may provide an avenue to study the transition from episodic to chronic headache. © Copyright © 2021 Levine, Liktor-Busa, Karlage, Giancotti, Salvemini, Vanderah and Largent-Milnes.
    • Daily intermittent fasting in mice enhances morphine-induced antinociception while mitigating reward, tolerance, and constipation

      Duron, David I; Hanak, Filip; Streicher, John M; Univ Arizona, Coll Med, Dept Pharmacol (LIPPINCOTT WILLIAMS & WILKINS, 2020-10)
      The opioid epidemic has plagued the United States with high levels of abuse and poor quality of life for chronic pain patients requiring continuous use of opioids. New drug discovery efforts have been implemented to mitigate this epidemic; however, new medications are still limited by low efficacy and/or high side effect and abuse potential. Intermittent fasting (IF) has recently been shown to improve a variety of pathological states, including stroke and neuroinflammation. Numerous animal and human studies have shown the benefits of IF in these disease states, but not in pain and opioid treatment. We thus subjected male and female CD-1 mice to 18-hour fasting intervals followed by 6-hour feed periods with standard chow for 1 week. Mice that underwent this diet displayed an enhanced antinociceptive response to morphine both in efficacy and duration using thermal tail-flick and postoperative paw incision pain models. While showing enhanced antinociception, IF mice also demonstrated no morphine reward and reduced tolerance and constipation. Seeking a mechanism for these improvements, we found that the mu-opioid receptor showed enhanced efficacy and reduced tolerance in the spinal cord and periaqueductal gray, respectively, from IF mice using a(35)S-GTP gamma S coupling assay. These improvements in receptor function were not due to changes in mu-opioid receptor protein expression. These data suggest that a daily IF diet may improve the therapeutic index of acute and chronic opioid therapies for pain patients in the clinic, providing a novel tool to improve patient therapy and reduce potential abuse.
    • Daily Morning Blue Light Therapy for Post-mTBI Sleep Disruption: Effects on Brain Structure and Function

      Raikes, Adam C.; Dailey, Natalie S.; Forbeck, Brittany; Alkozei, Anna; Killgore, William D. S.; Center for Innovation in Brain Science, University of Arizona; Social, Cognitive, and Affective Neuroscience Lab, University of Arizona (Frontiers Media S.A., 2021-02-05)
      Background: Mild traumatic brain injuries (mTBIs) are associated with novel or worsened sleep disruption. Several studies indicate that daily morning blue light therapy (BLT) is effective for reducing post-mTBI daytime sleepiness and fatigue. Studies demonstrating changes in brain structure and function following BLT are limited. The present study's purpose is to identify the effect of daily morning BLT on brain structure and functional connectivity and the association between these changes and self-reported change in post-mTBI daytime sleepiness. Methods: A total of 62 individuals recovering from a mTBI were recruited from two US cities to participate in a double-blind placebo-controlled trial. Eligible individuals were randomly assigned to undergo 6 weeks of 30 min daily morning blue or placebo amber light therapy (ALT). Prior to and following treatment all individuals completed a comprehensive battery that included the Epworth Sleepiness Scale as a measure of self-reported daytime sleepiness. All individuals underwent a multimodal neuroimaging battery that included anatomical and resting-state functional magnetic resonance imaging. Atlas-based regional change in gray matter volume (GMV) and region-to-region functional connectivity from baseline to post-treatment were the primary endpoints for this study. Results: After adjusting for pre-treatment GMV, individuals receiving BLT had greater GMV than those receiving amber light in 15 regions of interest, including the right thalamus and bilateral prefrontal and orbitofrontal cortices. Improved daytime sleepiness was associated with greater GMV in 74 ROIs, covering many of the same general regions. Likewise, BLT was associated with increased functional connectivity between the thalamus and both prefrontal and orbitofrontal cortices. Improved daytime sleepiness was associated with increased functional connectivity between attention and cognitive control networks as well as decreased connectivity between visual, motor, and attention networks (all FDR corrected p < 0.05). Conclusions: Following daily morning BLT, moderate to large increases in both gray matter volume and functional connectivity were observed in areas and networks previously associated with both sleep regulation and daytime cognitive function, alertness, and attention. Additionally, these findings were associated with improvements in self-reported daytime sleepiness. Further work is needed to identify the personal characteristics that may selectively identify individuals recovering from a mTBI for whom BLT may be optimally beneficial.
    • The Dalton-Zamoranos: Intimacy, Intermarriage, and Conquest in the U.S.-Mexico Borderlands

      Pérez, Erika; Univ Arizona, Hist; Univ Arizona, Gender & Womens Studies (UNIV CALIFORNIA PRESS, 2020-02-01)
      Relying on the experiences of the Dalton-Zamorano family of Rancho Azusa in Southern California, this article examines how a Californio family fared socially and economically from the mid-nineteenth century to the turn of the twentieth century, a period undergoing rapid social, political, economic, and cultural change. It focuses on the social and geographic borders that the Dalton-Zamoranos crossed culturally, racially, and spatially to pursue upward mobility and social integration. I argue that the Dalton-Zamoranos are a representative case study of biethnic families in Southern California and of the adaptations these families made following the geopolitical regime change. Outlined here is a story not only about struggle and misfortune but also of negotiation and survival by a once-prominent, ethnically mixed family whose trials and tribulations reflected rapid societal changes ushered by a new emergent industrial and capitalist order in the Southwest.
    • Damage inside borosilicate glass by a single picosecond laser pulse

      Cheng, W.; Pieterse, J.-W.; Liang, R.; Wyant College of Optical Sciences, University of Arizona (MDPI AG, 2021)
      We investigate damage inside the bulk of borosilicate glass by a single shot of IR picosecond laser pulse both experimentally and numerically. In our experiments, bulk damage of borosilicate glass with aspect ratio of about 1:10 is generated. The shape and size of the damage site are shown to correspond to an electron cloud with density of about 1020 cm−3 . The underlying mechanism of electron generation by multiphoton ionization and avalanche ionization is numerically investigated. The multiphoton ionization rate and avalanche ionization rate are determined by fitting experimental results. The relative role of multiphoton ionization and avalanche ionization are numerically studied and the percentage of electron contribution from each ionization channel is determined. © 2021 by the authors. Licensee MDPI, Basel, Switzerland.
    • Damage localization in piezo-ceramic using ultrasonic waves excited by dual point contact excitation and detection scheme

      Agarwal, V.; Shelke, A.; Ahluwalia, B.S.; Melandsø, F.; Kundu, T.; Habib, A.; Univ Arizona, Dept Civil & Architectural Engn & Mech (Elsevier BV, 2020-12)
      A novel experimental technique based on point contact and Coulomb coupling is devised and optimized for ultrasonic imaging of bulk and guided waves propagation in piezo-ceramics. The Coulomb coupling technique exploits the coupling and transfer of electric field to mechanical vibrations by excitation of phonons. The point contact excitation and detection technique facilitates the spatial-temporal imaging of ultrasonic waves. The motivation of this research is the diagnosis and localization of surface cracks in the piezoelectric sensors and actuators. The underlying principle of the detection scheme is that any discontinuity on the surface causes high localization of electric gradient. The localized electric field at the defect boundaries enables then to behave as secondary passive ultrasonic sources resulting in strong back reflections. However, due to the interference between transmitted and reflected wave components from rigid boundaries and defect, the resolution on the localization of the damage is challenging. Therefore, an algorithm based on the two-dimensional spectral decomposition is utilized for selective suppression of the transmitted wave. The algorithm includes data transformation and vectorization in polar coordinates for efficient spectral decomposition. In the spectral domain, the complex wave component (phase and amplitude) are suppressed for the transmitted wave field. The reflected wave component in the spectral domain is retained and retrieved back using inverse spectral transformation. The algorithm is successful in retaining and exemplifying only the reflected wave sources arising from the strong scattering of ultrasonic waves from the surface and sub-surface defects. In summary, a novel experimental technique based on Coulomb coupling and spectral decomposition technique has been implemented for localization of surface defect in piezo-ceramic structures.
    • Damming the rivers of the Amazon basin

      Latrubesse, Edgardo M.; Arima, Eugenio Y.; Dunne, Thomas; Park, Edward; Baker, Victor R.; d’Horta, Fernando M.; Wight, Charles; Wittmann, Florian; Zuanon, Jansen; Baker, Paul A.; et al. (NATURE PUBLISHING GROUP, 2017-06-14)
      More than a hundred hydropower dams have already been built in the Amazon basin and numerous proposals for further dam constructions are under consideration. The accumulated negative environmental effects of existing dams and proposed dams, if constructed, will trigger massive hydrophysical and biotic disturbances that will affect the Amazon basin's floodplains, estuary and sediment plume. We introduce a Dam Environmental Vulnerability Index to quantify the current and potential impacts of dams in the basin. The scale of foreseeable environmental degradation indicates the need for collective action among nations and states to avoid cumulative, far-reaching impacts. We suggest institutional innovations to assess and avoid the likely impoverishment of Amazon rivers.
    • The Dangers of Reading Globally

      Short, Kathy G.; Univ Arizona, Coll Educ (JOHNS HOPKINS UNIVERSITY PRESS FOR INT BOARD BOOKS YOUNG PEOPLE, 2019)
      This article is based on a keynote delivered at the 36th IBBY International Congress in Athens, Greece, on August 31, 2018. IBBY members are committed to the potentials offered by global literature for opening minds to multiple ways of living in the world and creating intercultural understanding. Asking readers to read outside their comfort zones, however, can instead hold danger and perpetuate stereotypes and misunderstandings. This article proposes that we can address these dangers through acting on our social responsibilities as bookmakers, readers, and educators to balance individual voice with group responsibility and to determine if our actions could cause harm to readers' understandings of a culture.
    • A DARK ENERGY CAMERA SEARCH FOR AN OPTICAL COUNTERPART TO THE FIRST ADVANCED LIGO GRAVITATIONAL WAVE EVENT GW150914

      Soares-Santos, M.; Kessler, R.; Berger, E.; Annis, J.; Brout, D.; Buckley-Geer, E.; Chen, H.; Cowperthwaite, P. S.; Diehl, H. T.; Doctor, Z.; et al. (IOP PUBLISHING LTD, 2016-05-27)
      We report the results of a deep search for an optical counterpart to the gravitational wave (GW) event GW150914, the first trigger from the Advanced LIGO GW detectors. We used the Dark Energy Camera (DECam) to image a 102 deg(2) area, corresponding to 38% of the initial trigger high-probability sky region and to 11% of the revised high-probability region. We observed in the i and z bands at 4-5, 7, and 24 days after the trigger. The median 5 sigma point-source limiting magnitudes of our search images are i = 22.5 and z = 21.8 mag. We processed the images through a difference-imaging pipeline using templates from pre-existing Dark Energy Survey data and publicly available DECam data. Due to missing template observations and other losses, our effective search area subtends 40 deg(2), corresponding to a 12% total probability in the initial map and 3% in the final map. In this area, we search for objects that decline significantly between days 4-5 and day 7, and are undetectable by day 24, finding none to typical magnitude limits of i = 21.5, 21.1, 20.1 for object colors (i - z) = 1, 0, - 1, respectively. Our search demonstrates the feasibility of a dedicated search program with DECam and bodes well for future research in this emerging field.
    • A DARK ENERGY CAMERA SEARCH FOR MISSING SUPERGIANTS IN THE LMC AFTER THE ADVANCED LIGO GRAVITATIONAL-WAVE EVENT GW150914

      Annis, J.; Soares-Santos, M.; Berger, E.; Brout, D.; Chen, H.; Chornock, R.; Cowperthwaite, P. S.; Diehl, H. T.; Doctor, Z.; Drlica-Wagner, A.; et al. (IOP PUBLISHING LTD, 2016-05-27)
      The collapse of a stellar core is expected to produce gravitational waves (GWs), neutrinos, and in most cases a luminous supernova. Sometimes, however, the optical event could be significantly less luminous than a supernova and a direct collapse to a black hole, where the star just disappears, is possible. The GW event GW150914 was detected by the LIGO Virgo Collaboration via a burst analysis that gave localization contours enclosing the Large Magellanic Cloud (LMC). Shortly thereafter, we used DECam to observe 102 deg(2) of the localization area, including 38 deg(2) on the LMC for a missing supergiant search. We construct a complete catalog of LMC luminous red supergiants, the best candidates to undergo invisible core collapse, and collected catalogs of other candidates: less luminous red supergiants, yellow supergiants, blue supergiants, luminous blue variable stars, and Wolf-Rayet stars. Of the objects in the imaging region, all are recovered in the images. The timescale for stellar disappearance is set by the free-fall time, which is a function of the stellar radius. Our observations at 4 and 13 days after the event result in a search sensitive to objects of up to about 200 solar radii. We conclude that it is unlikely that GW150914 was caused by the core collapse of a relatively compact supergiant in the LMC, consistent with the LIGO Collaboration analyses of the gravitational waveform as best interpreted as a high mass binary black hole merger. We discuss how to generalize this search for future very nearby core-collapse candidates.
    • Dark Energy Survey identification of a low-mass active galactic nucleus at redshift 0.823 from optical variability

      Guo, Hengxiao; Burke, Colin J; Liu, Xin; Phadke, Kedar A; Zhang, Kaiwen; Chen, Yu-Ching; Gruendl, Robert A; Lidman, Christopher; Shen, Yue; Morganson, Eric; et al. (OXFORD UNIV PRESS, 2020-06-23)
      We report the identification of a low-mass active galactic nucleus (AGN), DES J0218-0430, in a redshift z = 0.823 galaxy in the Dark Energy Survey (DES) Supernova field. We select DES J0218-0430 as an AGN candidate by characterizing its long-term optical variability alone based on DES optical broad-band light curves spanning over 6 yr. An archival optical spectrum from the fourth phase of the Sloan Digital Sky Survey shows both broad MgII and broad H beta lines, confirming its nature as a broad-line AGN. Archival XMM-Newton X-ray observations suggest an intrinsic hard X-ray luminosity of L2-12 keV approximate to 7.6 +/- 0.4 x 10(43) erg s(-1), which exceeds those of the most X-ray luminous starburst galaxies, in support of an AGN driving the optical variability. Based on the broad H beta from SDSS spectrum, we estimate a virial black hole (BH) mass of M-circle approximate to 10(6.43) - 10(6.72) M-circle dot (with the error denoting the systematic uncertainty from different calibrations), consistent with the estimation from OzDES, making it the lowest mass AGN with redshift > 0.4 detected in optical. We estimate the host galaxy stellar mass to be M-* approximate to 10(10.5 +/- 0.3) M-circle dot based on modelling the multiwavelength spectral energy distribution. DES J0218-0430 extends the M-circle-M-* relation observed in luminous AGNs at z similar to 1 to masses lower than being probed by previous work. Our work demonstrates the feasibility of using optical variability to identify low-mass AGNs at higher redshift in deeper synoptic surveys with direct implications for the upcoming Legacy Survey of Space and Time at Vera C. Rubin Observatory.
    • Dark energy survey operations: years 4 and 5

      Diehl, H. Thomas; Neilsen, Eric; Gruendl, Robert A.; Abbott, Timothy M. C.; Allam, Sahar; Alvarez, Otto; Annis, James; Balbinot, Eduardo; Bhargava, Sunayana; Bechtol, Keith; et al. (SPIE-INT SOC OPTICAL ENGINEERING, 2018-07-10)
      The Dark Energy Survey (DES) is an operating optical survey aimed at understanding the accelerating expansion of the universe using four complementary methods: weak gravitational lensing, galaxy cluster counts, baryon acoustic oscillations, and Type Ia supernovae. To perform the 5000 sq-degree wide field and 30 sq-degree supernova surveys, the DES Collaboration built the Dark Energy Camera (DECam), a 3 square-degree, 570-Megapixel CCD camera that was installed at the prime focus of the Blanco 4-meter telescope at the Cerro Tololo Inter-American Observatory (CTIO). DES has completed its third observing season out of a nominal five. This paper describes DES "Year 4" (Y4) and "Year 5" (Y5), the survey strategy, an outline of the survey operations procedures, the efficiency of operations and the causes of lost observing time. It provides details about the quality of these two-season's data, a summary of the overall status, and plans for the final survey season.
    • Dark Energy Survey Year 1 Results: Cosmological constraints from cluster abundances and weak lensing

      DES Collaboration; Univ Arizona, Dept Astron; Univ Arizona, Dept Phys (AMER PHYSICAL SOC, 2020)
      We perform a joint analysis of the counts and weak lensing signal of redMaPPer clusters selected from the Dark Energy Survey (DES) Year 1 dataset. Our analysis uses the same shear and source photometric redshifts estimates as were used in the DES combined probes analysis. Our analysis results in surprisingly low values for S-8 = sigma(8)(Omega(m)/0.3)(0.5) = 0.65 0.04, driven by a low matter density parameter, Omega(m) = 0.179(-0.038)(+0.031), with sigma(8) - Omega(m) posteriors in 2.4 sigma tension with the DES Y1 3x2pt results, and in 5.6 sigma with the Planck CMB analysis. These results include the impact of post-unblinding changes to the analysis, which did not improve the level of consistency with other data sets compared to the results obtained at the unblinding. The fact that multiple cosmological probes (supernovae, baryon acoustic oscillations, cosmic shear, galaxy clustering and CMB anisotropies), and other galaxy cluster analyses all favor significantly higher matter densities suggests the presence of systematic errors in the data or an incomplete modeling of the relevant physics. Cross checks with x-ray and microwave data, as well as independent constraints on the observable -mass relation from Sunyaev-Zeldovich selected clusters, suggest that the discrepancy resides in our modeling of the weak lensing signal rather than the cluster abundance. Repeating our analysis using a higher richness threshold (lambda >= 30) significantly reduces the tension with other probes, and points to one or more richness -dependent effects not captured by our model.
    • Dark Energy Survey Year 1 Results: Cosmological Constraints from Cluster Abundances, Weak Lensing, and Galaxy Correlations

      DES Collaboration; Department of Astronomy/Steward Observatory, Department of Physics, University of Arizona, (American Physical Society, 2021)
      We present the first joint analysis of cluster abundances and auto or cross-correlations of three cosmic tracer fields: galaxy density, weak gravitational lensing shear, and cluster density split by optical richness. From a joint analysis (4×2pt+N) of cluster abundances, three cluster cross-correlations, and the auto correlations of the galaxy density measured from the first year data of the Dark Energy Survey, we obtain ωm=0.305-0.038+0.055 and σ8=0.783-0.054+0.064. This result is consistent with constraints from the DES-Y1 galaxy clustering and weak lensing two-point correlation functions for the flat νΛCDM model. Consequently, we combine cluster abundances and all two-point correlations from across all three cosmic tracer fields (6×2pt+N) and find improved constraints on cosmological parameters as well as on the cluster observable-mass scaling relation. This analysis is an important advance in both optical cluster cosmology and multiprobe analyses of upcoming wide imaging surveys. © 2021 American Physical Society.
    • Dark Energy Survey Year 1 results: Cosmological constraints from cosmic shear

      Troxel, M. A.; MacCrann, N.; Zuntz, J.; Eifler, T. F.; Krause, E.; Dodelson, S.; Gruen, D.; Blazek, J.; Friedrich, O.; Samuroff, S.; et al. (AMER PHYSICAL SOC, 2018-08-27)
      We use 26 x 10(6) galaxies from the Dark Energy Survey (DES) Year 1 shape catalogs over 1321 deg(2) of the sky to produce the most significant measurement of cosmic shear in a galaxy survey to date. We constrain cosmological parameters in both the flat Lambda CDM and the wCDM models, while also varying the neutrino mass density. These results are shown to be robust using two independent shape catalogs, two independent photo-z calibration methods, and two independent analysis pipelines in a blind analysis. We find a 3.5% fractional uncertainty on sigma(8) (Omega(m)/0.3)(0.5) = 0.782(- 0.027)(+0.027) at 68% C. L., which is a factor of 2.5 improvement over the fractional constraining power of our DES Science Verification results. In wCDM, we find a 4.8% fractional uncertainty on sigma(8) (Omega(m)/0.3)(0.5) = 0.777(-0.038)(+0.036) and a dark energy equation-of-state w = -0.95(-0.39)(+0.33) . We find results that are consistent with previous cosmic shear constraints in sigma(8)-Omega(m), and we see no evidence for disagreement of our weak lensing data with data from the cosmic microwave background. Finally, we find no evidence preferring a wCDM model allowing w not equal -1. We expect further significant improvements with subsequent years of DES data, which will more than triple the sky coverage of our shape catalogs and double the effective integrated exposure time per galaxy.
    • Dark Energy Survey year 1 results: Cosmological constraints from galaxy clustering and weak lensing

      Abbott, T. M. C.; Abdalla, F. B.; Alarcon, A.; Aleksić, J.; Allam, S.; Allen, S.; Amara, A.; Annis, J.; Asorey, J.; Avila, S.; et al. (AMER PHYSICAL SOC, 2018-08-27)
      We present cosmological results from a combined analysis of galaxy clustering and weak gravitational lensing, using 1321 deg(2) of griz imaging data from the first year of the Dark Energy Survey (DES Y1). We combine three two-point functions: (i) the cosmic shear correlation function of 26 million source galaxies in four redshift bins, (ii) the galaxy angular autocorrelation function of 650,000 luminous red galaxies in five redshift bins, and (iii) the galaxy-shear cross-correlation of luminous red galaxy positions and source galaxy shears. To demonstrate the robustness of these results, we use independent pairs of galaxy shape, photometric-redshift estimation and validation, and likelihood analysis pipelines. To prevent confirmation bias, the bulk of the analysis was carried out while "blind" to the true results; we describe an extensive suite of systematics checks performed and passed during this blinded phase. The data are modeled in flat Lambda CDM and wCDM cosmologies, marginalizing over 20 nuisance parameters, varying 6 (for Lambda CDM) or 7 (for wCDM) cosmological parameters including the neutrino mass density and including the 457 x 457 element analytic covariance matrix. We find consistent cosmological results from these three two-point functions and from their combination obtain S-8 equivalent to sigma(8) (Omega(m)/0.3)(0.5) = 0.773(-0.020)(+0.026) and Omega(m) = 0.267(-0.017)(+0.030) for Lambda CDM; for wCDM, we find S-8 = 0.782(-0.024)(+0.036) , Omega(m) = 0.284(-0.030)(+0.033), and w = -0.82(-0.20)(+0.21) at 68% C.L. The precision of these DES Y1 constraints rivals that from the Planck cosmic microwave background measurements, allowing a comparison of structure in the very early and late Universe on equal terms. Although the DES Y1 best-fit values for S-8 and Omega(m) are lower than the central values from Planck for both Lambda CDM and wCDM, the Bayes factor indicates that the DES Y1 and Planck data sets are consistent with each other in the context of Lambda CDM. Combining DES Y1 with Planck, baryonic acoustic oscillation measurements from SDSS, 6dF, and BOSS and type Ia supernovae from the Joint Lightcurve Analysis data set, we derive very tight constraints on cosmological parameters: S-8 = 0.802 +/- 0.012 and Omega(m) = 0.298 +/- 0.007 in Lambda CDM and w = -1.00(-0.04)(+0.05) in wCDM. Upcoming Dark Energy Survey analyses will provide more stringent tests of the Lambda CDM model and extensions such as a time-varying equation of state of dark energy or modified gravity.
    • Dark Energy Survey Year 1 Results: Cross-correlation between Dark Energy Survey Y1 galaxy weak lensing and South Pole Telescope+Planck CMB weak lensing

      Rozo, E.; Marrone, D. P.; Univ Arizona, Dept Phys; Univ Arizona, Steward Observ (AMER PHYSICAL SOC, 2019-08-12)
      We cross-correlate galaxy weak lensing measurements from the Dark Energy Survey (DES) year-one data with a cosmic microwave background (CMB) weak lensing map derived from South Pole Telescope (SPT) and Planck data, with an effective overlapping area of 1289 deg(2). With the combined measurements from four source galaxy redshift bins, we obtain a detection significance of 5.8 sigma. We fit the amplitude of the correlation functions while fixing the cosmological parameters to a fiducial Lambda CDM model, finding A = 0.99 +/- 0.17. We additionally use the correlation function measurements to constrain shear calibration bias, obtaining constraints that are consistent with previous DES analyses. Finally, when performing a cosmological analysis under the Lambda CDM model, we obtain the marginalized constraints of Omega(m) = 0.261(-0.051)(+0.070) and S-8 = sigma(8)root Omega(m)/0.3 = 0.660(-0.100)(+0.085). These measurements are used in a companion work that presents cosmological constraints from the joint analysis of two-point functions among galaxies, galaxy shears, and CMB lensing using DES, SPT, and Planck data.
    • Dark Energy Survey Year 1 results: cross-correlation redshifts – methods and systematics characterization

      Gatti, M; Vielzeuf, P; Davis, C; Cawthon, R; Rau, M M; DeRose, J; De Vicente, J; Alarcon, A; Rozo, E; Gaztanaga, E; et al. (OXFORD UNIV PRESS, 2018-06)
      We use numerical simulations to characterize the performance of a clustering-based method to calibrate photometric redshift biases. In particular, we cross-correlate the weak lensing source galaxies from the Dark Energy Survey Year 1 sample with redMaGiC galaxies (luminous red galaxies with secure photometric redshifts) to estimate the redshift distribution of the former sample. The recovered redshift distributions are used to calibrate the photometric redshift bias of standard photo-z methods applied to the same source galaxy sample. We apply the method to two photo-z codes run in our simulated data: Bayesian Photometric Redshift and Directional Neighbourhood Fitting. We characterize the systematic uncertainties of our calibration procedure, and find that these systematic uncertainties dominate our error budget. The dominant systematics are due to our assumption of unevolving bias and clustering across each redshift bin, and to differences between the shapes of the redshift distributions derived by clustering versus photo-zs. The systematic uncertainty in the mean redshift bias of the source galaxy sample is Delta z less than or similar to 0.02, though the precise value depends on the redshift bin under consideration. We discuss possible ways to mitigate the impact of our dominant systematics in future analyses.
    • Dark Energy Survey Year 1 results: curved-sky weak lensing mass map

      Chang, C; Pujol, A; Mawdsley, B; Bacon, D; Elvin-Poole, J; Melchior, P; Kovács, A; Jain, B; Leistedt, B; Giannantonio, T; et al. (OXFORD UNIV PRESS, 2018-04)
      We construct the largest curved-sky galaxy weak lensing mass map to date from the DES first-year (DES Y1) data. The map, about 10 times larger than the previous work, is constructed over a contiguous approximate to 1500 deg(2), covering a comoving volume of approximate to 10 Gpc(3). The effects of masking, sampling, and noise are tested using simulations. We generate weak lensing maps from two DES Y1 shear catalogues, METACALIBRATION and IM3SHAPE, with sources at red-shift 0.2 < z < 1.3, and in each of four bins in this range. In the highest signal-to-noise map, the ratio between the mean signal to noise in the E-mode map and the B-mode map is similar to 1.5 (similar to 2) when smoothed with a Gaussian filter of sigma(G) = 30 (80) arcmin. The second and third moments of the convergence kappa in the maps are in agreement with simulations. We also find no significant correlation of kappa with maps of potential systematic contaminants. Finally, we demonstrate two applications of the mass maps: (1) cross-correlation with different foreground tracers of mass and (2) exploration of the largest peaks and voids in the maps.