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A combined analysis of 3D weak lensing, Lyman-α forest and WMAP year three data

Lesgourgues, J. and Viel, M. and Haehnelt, M. G. and Massey, R. (2007) A combined analysis of 3D weak lensing, Lyman-α forest and WMAP year three data. Journal of Cosmology and Astroparticle Physics, 2007 (11). Art. No. 008. ISSN 1475-7516. https://resolver.caltech.edu/CaltechAUTHORS:LESjcap07

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Abstract

We present constraints on the amplitude and shape of the matter power spectrum and the density of dark matter within the framework of a standard ΛCDM model. We use a Markov chain Monte Carlo approach to combine independent measurements of the three-dimensional weak gravitational lensing shear field by the COSMOS survey, of low- and high-resolution Lyman-α (Lyα) forest flux power spectrum by SDSS and LUQAS, and of cosmic microwave background temperature and polarization anisotropies by WMAP. We note good agreement between the amplitude of the matter power spectrum on intermediate and small scales as inferred from Lyα forest and lensing data. The Lyα forest data help to break the σ8–Ω0m degeneracy characteristic of weak lensing results, yielding σ8 = 0.876 ± 0.048 for COSMOS plus Lyα SDSS data. This is somewhat larger than the value preferred by the WMAP year three CMB data. Combining all three data sets significantly tightens the constraints on σ8, the spectral index of primordial density fluctuation ns, a possible running of the spectral index nrun and the matter density Ω0m. Assuming no running, the joint constraints for COSMOS, SDSS and WMAP are σ8 = 0.800 ± 0.023, ns = 0.971 ± 0.011, Ω0m = 0.247 ± 0.016 (1-σ error bars).


Item Type:Article
Additional Information:Copyright © SISSA and IOP Publishing Limited 2007. Received 7 May 2007, accepted for publication 8 October 2007. Published 9 November 2007. Computations were done at the UK National Cosmology Supercomputer Center funded by PPARC, HEFCE and Silicon Graphics/Cray Research and at the HPCF (Cambridge High Performance Computer Cluster), as well as on the MUST cluster in LAPP, Annecy (CNRS & Université de Savoie). JL acknowledges partial support from the EU 6th Framework Marie Curie Research and Training network 'UniverseNet' (MRTN-CT-2006-035863). E-print number: 0705.0533
Subject Keywords:CMBR experiments; classical tests of cosmology; gravitational lensing; power spectrum
Issue or Number:11
Record Number:CaltechAUTHORS:LESjcap07
Persistent URL:https://resolver.caltech.edu/CaltechAUTHORS:LESjcap07
Alternative URL:http://dx.doi.org/10.1088/1475-7516/2007/11/008
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:9198
Collection:CaltechAUTHORS
Deposited By: Archive Administrator
Deposited On:20 Nov 2007
Last Modified:02 Oct 2019 23:58

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