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The WiggleZ Dark Energy Survey: probing the epoch of radiation domination using large-scale structure

Poole, Gregory B. and Forster, Karl and Martin, D. Christopher and Wyder, Ted K. (2013) The WiggleZ Dark Energy Survey: probing the epoch of radiation domination using large-scale structure. Monthly Notices of the Royal Astronomical Society, 429 (3). pp. 1902-1912. ISSN 0035-8711.

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We place the most robust constraint to date on the scale of the turnover in the cosmological matter power spectrum using data from the WiggleZ Dark Energy Survey. We find this feature to lie at a scale of k_0 = 0.0160^(+ 0.0035)_(− 0.0041) (h Mpc^−1) (68 per cent confidence) for an effective redshift of z_(eff) = 0.62 and obtain from this the first ever turnover-derived distance and cosmology constraints: a measure of the cosmic distance–redshift relation in units of the horizon scale at the redshift of radiation–matter equality (r_H) of D_V(z_(eff) = 0.62)/r_H = 18.3^(+6.3)_(−3.3) and, assuming a prior on the number of extra relativistic degrees of freedom N_(eff) = 3, constraints on the cosmological matter density parameter Ω_M h^2 = 0.136^(+0.026)_(−0.052) and on the redshift of matter–radiation equality z_(eq) = 3274^(+631)_(−1260). We stress that these results are obtained within the theoretical framework of Gaussian primordial fluctuations and linear large-scale bias. With this caveat, all results are in excellent agreement with the predictions of standard ΛCDM models. Our constraints on the logarithmic slope of the power spectrum on scales larger than the turnover are bounded in the lower limit with values only as low as −1 allowed, with the prediction of P(k) ∝ k from standard ΛCDM models easily accommodated by our results. Finally, we generate forecasts to estimate the achievable precision of future surveys at constraining k_0, Ω_M h^2, z_(eq) and N_(eff). We find that the Baryon Oscillation Spectroscopic Survey should substantially improve upon the WiggleZ turnover constraint, reaching a precision on k_0 of ±9 per cent (68 per cent confidence), translating to precisions on Ω_M h^2 and z_(eq) of ±10 per cent (assuming a prior N_(eff) = 3) and on Neff of + 78− 56 per cent (assuming a prior Ω_M h^2 = 0.135). This represents sufficient precision to sharpen the constraints on N_(eff) from WMAP, particularly in its upper limit. For Euclid, we find corresponding attainable precisions on (k_0, Ω_M h^2, N_(eff)) of (3, 4,^(+ 17)_(− 21)) per cent. This represents a precision approaching our forecasts for the Planck Surveyor.

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Forster, Karl0000-0001-5800-5531
Martin, D. Christopher0000-0002-8650-1644
Additional Information:© 2013 The Authors. Published by Oxford University Press on behalf of the Royal Astronomical Society. First published online: January 4, 2013. Accepted 2012 November 16. Received 2012 November 16; in original form 2012 August 31. We thank Francesco Montesano for his constructive and insightful examination of our manuscript. We acknowledge financial support from the Australian Research Council through Discovery Project grants DP0772084 and DP1093738 and Linkage International travel grant LX0881951. GBP thanks Simon Mutch for his help with developing the MCMC code used for the analysis in this study. CB acknowledges the support of the Australian Research Council through the award of a Future Fellowship. SC and DJC acknowledge the support of Australian Research Council QEII Fellowships. MJD and TD thank the Gregg Thompson Dark Energy Travel Fund for financial support. The Galaxy Evolution Explorer (GALEX) is a NASA Small Explorer, launched in 2003 April. We gratefully acknowledge NASAÕ’s support for construction, operation and science analysis for the GALEX mission, developed in cooperation with the Centre National d'Etudes Spatiales of France and the Korean Ministry of Science and Technology.We thank the Anglo-Australian Telescope Allocation Committee for supporting theWiggleZ survey over nine semesters, and we are very grateful for the dedicated work of the staff of the Australian Astronomical Observatory in the development and support of the AAOmega spectrograph, and the running of the Anglo-Australian Telescope.We are also grateful for support from the Centre for All-sky Astrophysics, an Australian Research Council Centre of Excellence funded by grant CE11000102.
Group:Space Astrophysics Laboratory
Funding AgencyGrant Number
Australian Research Council Discovery ProjectDP0772084
Australian Research Council Discovery ProjectDP1093738
Linkage International Travel GrantLX0881951
Australian Research Council Future FellowshipUNSPECIFIED
Australian Research Council QEII FellowshipsUNSPECIFIED
Gregg Thompson Dark Energy Travel FundUNSPECIFIED
Australian Research Council Centre of ExcellenceCE110001020
Subject Keywords: surveys cosmological parameters large-scale structure of Universe
Issue or Number:3
Record Number:CaltechAUTHORS:20130625-101556024
Persistent URL:
Official Citation: Gregory B. Poole, Chris Blake, David Parkinson, Sarah Brough, Matthew Colless, Carlos Contreras, Warrick Couch, Darren J. Croton, Scott Croom, Tamara Davis, Michael J. Drinkwater, Karl Forster, David Gilbank, Mike Gladders, Karl Glazebrook, Ben Jelliffe, Russell J. Jurek, I-hui Li, Barry Madore, D. Christopher Martin, Kevin Pimbblet, Michael Pracy, Rob Sharp, Emily Wisnioski, David Woods, Ted K. Wyder, and H. K. C. Yee The WiggleZ Dark Energy Survey: probing the epoch of radiation domination using large-scale structure MNRAS (March 1, 2013) Vol. 429 1902-1912 first published online January 4, 2013 doi:10.1093/mnras/sts431
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:39074
Deposited By: Ruth Sustaita
Deposited On:25 Jun 2013 18:06
Last Modified:09 Mar 2020 23:41

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