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Cosmology from cosmic shear with Dark Energy Survey Science Verification data

Abbott, T; Abdalla, FB; Allam, S; Amara, A; Annis, J; Armstrong, R; Bacon, D; ... Zuntz, J; + view all (2016) Cosmology from cosmic shear with Dark Energy Survey Science Verification data. Physical Review D , 94 (2) , Article 022001. 10.1103/PhysRevD.94.022001. Green open access

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Abstract

We present the first constraints on cosmology from the Dark Energy Survey (DES), using weak lensing measurements from the preliminary Science Verification (SV) data. We use 139 square degrees of SV data, which is less than 3% of the full DES survey area. Using cosmic shear 2-point measurements over three redshift bins we find σ 8 ( Ω m / 0.3 ) 0.5 = 0.81 ± 0.06 (68% confidence), after marginalizing over 7 systematics parameters and 3 other cosmological parameters. We examine the robustness of our results to the choice of data vector and systematics assumed, and find them to be stable. About 20% of our error bar comes from marginalizing over shear and photometric redshift calibration uncertainties. The current state-of-the-art cosmic shear measurements from CFHTLenS are mildly discrepant with the cosmological constraints from Planck CMB data; our results are consistent with both data sets. Our uncertainties are ∼ 30 % larger than those from CFHTLenS when we carry out a comparable analysis of the two data sets, which we attribute largely to the lower number density of our shear catalogue. We investigate constraints on dark energy and find that, with this small fraction of the full survey, the DES SV constraints make negligible impact on the Planck constraints. The moderate disagreement between the CFHTLenS and Planck values of σ 8 ( Ω m / 0.3 ) 0.5 is present regardless of the value of w .

Type: Article
Title: Cosmology from cosmic shear with Dark Energy Survey Science Verification data
Open access status: An open access version is available from UCL Discovery
DOI: 10.1103/PhysRevD.94.022001
Publisher version: http://doi.org/10.1103/PhysRevD.94.022001
Language: English
Additional information: © 2016 American Physical Society
Keywords: Science & Technology, Physical Sciences, Astronomy & Astrophysics, Physics, Particles & Fields, Physics, MATTER POWER SPECTRUM, WEAK-LENSING TOMOGRAPHY, LARGE-SCALE STRUCTURE, BARYON ACOUSTIC-OSCILLATIONS, INTRINSIC ALIGNMENTS, PARAMETER CONSTRAINTS, GALAXY ELLIPTICITIES, PRECISION COSMOLOGY, COVARIANCE-MATRIX, HUBBLE CONSTANT
UCL classification: UCL
UCL > Provost and Vice Provost Offices > UCL BEAMS
UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences
UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences > Dept of Physics and Astronomy
URI: https://discovery.ucl.ac.uk/id/eprint/1504353
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