Cosmology from cosmic shear with Dark Energy Survey Science Verification data
File(s)
Accepted version
Author(s)
Type
Journal Article
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
.
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
.
Date Issued
2016-07-06
Date Acceptance
2016-07-01
Citation
Physical Review D: Particles, Fields, Gravitation and Cosmology, 2016, 94 (2), pp.022001 – 1-022001 – 22
ISSN
1550-2368
Publisher
American Physical Society
Start Page
022001 – 1
End Page
022001 – 22
Journal / Book Title
Physical Review D: Particles, Fields, Gravitation and Cosmology
Volume
94
Issue
2
Copyright Statement
© 2016 American Physical Society
Identifier
http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000379682300001&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=1ba7043ffcc86c417c072aa74d649202
Subjects
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
Publication Status
Published
Article Number
ARTN 022001
Date Publish Online
2016-07-06