Cosmological parameters, shear maps and power spectra from CFHTLenS using Bayesian hierarchical inference

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Title: Cosmological parameters, shear maps and power spectra from CFHTLenS using Bayesian hierarchical inference
Author(s): Alsing, J
Heavens, A
Jaffe, AH
Item Type: Journal Article
Abstract: We apply two Bayesian hierarchical inference schemes to infer shear power spectra, shear maps and cosmological parameters from the Canada–France–Hawaii Telescope (CFHTLenS) weak lensing survey – the first application of this method to data. In the first approach, we sample the joint posterior distribution of the shear maps and power spectra by Gibbs sampling, with minimal model assumptions. In the second approach, we sample the joint posterior of the shear maps and cosmological parameters, providing a new, accurate and principled approach to cosmological parameter inference from cosmic shear data. As a first demonstration on data, we perform a two-bin tomographic analysis to constrain cosmological parameters and investigate the possibility of photometric redshift bias in the CFHTLenS data. Under the baseline ΛCDM (Λ cold dark matter) model, we constrain S8=σ8(Ωm/0.3)0.5=0.67+0.03−0.03 S8=σ8(Ωm/0.3)0.5=0.67−0.03+0.03 (68 per cent), consistent with previous CFHTLenS analyses but in tension with Planck. Adding neutrino mass as a free parameter, we are able to constrain ∑mν < 4.6 eV (95 per cent) using CFHTLenS data alone. Including a linear redshift-dependent photo-z bias Δz = p2(z − p1), we find p1=−0.25+0.53−0.60 p1=−0.25−0.60+0.53 and p2=−0.15+0.17−0.15 p2=−0.15−0.15+0.17 , and tension with Planck is only alleviated under very conservative prior assumptions. Neither the non-minimal neutrino mass nor photo-z bias models are significantly preferred by the CFHTLenS (two-bin tomography) data.
Publication Date: 10-Dec-2016
Date of Acceptance: 2-Dec-2016
URI: http://hdl.handle.net/10044/1/47998
DOI: https://dx.doi.org/10.1093/mnras/stw3161
ISSN: 0035-8711
Publisher: Oxford University Press
Start Page: 3272
End Page: 3292
Journal / Book Title: MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
Volume: 466
Issue: 3
Copyright Statement: © 2016 The Author(s). Published by Oxford University Press on behalf of the Royal Astronomical Society.
Keywords: Science & Technology
Physical Sciences
Astronomy & Astrophysics
gravitational lensing: weak
methods: statistical
cosmological parameters
large-scale structure of Universe
MICROWAVE BACKGROUND DATA
TELESCOPE LENSING SURVEY
COSMIC SHEAR
REDSHIFT DISTRIBUTIONS
GALAXY SURVEYS
PLANCK CMB
LIKELIHOOD
APPROXIMATION
CONSTRAINTS
DISCORDANCE
Astronomy & Astrophysics
0201 Astronomical And Space Sciences
Publication Status: Published
Appears in Collections:Physics
Astrophysics
Faculty of Natural Sciences



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