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Effects of cosmological model assumptions on galaxy redshift survey measurements

Samushia, L.; Percival, W.J.; Guzzo, L.; Wang, Y.; Cimatti, A.; Baugh, C.; Geach, J.E.; Lacey, C.; Majerotto, E.; Mukherjee, P.; Orsi, A.

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L. Samushia

W.J. Percival

L. Guzzo

Y. Wang

A. Cimatti

J.E. Geach

E. Majerotto

P. Mukherjee

A. Orsi


The clustering of galaxies observed in future redshift surveys will provide a wealth of cosmological information. Matching the signal at different redshifts constrains the dark energy driving the acceleration of the expansion of the Universe. In tandem with these geometrical constraints, redshift-space distortions depend on the build up of large-scale structure. As pointed out by many authors, measurements of these effects are intrinsically coupled. We investigate this link and argue that it strongly depends on the cosmological assumptions adopted when analysing data. Using representative assumptions for the parameters of the Euclid survey in order to provide a baseline future experiment, we show how the derived constraints change due to different model assumptions. We argue that even the assumption of a Friedman–Robertson–Walker space–time is sufficient to reduce the importance of the coupling to a significant degree. Taking this idea further, we consider how the data would actually be analysed and argue that we should not expect to be able to simultaneously constrain multiple deviations from the standard Λ cold dark matter (ΛCDM) model. We therefore consider different possible ways in which the Universe could deviate from the ΛCDM model, and show how the coupling between geometrical constraints and structure growth affects the measurement of such deviations.


Samushia, L., Percival, W., Guzzo, L., Wang, Y., Cimatti, A., Baugh, C., …Orsi, A. (2011). Effects of cosmological model assumptions on galaxy redshift survey measurements. Monthly Notices of the Royal Astronomical Society, 410(3), 1993-2002.

Journal Article Type Article
Publication Date Jan 21, 2011
Deposit Date Jan 31, 2012
Publicly Available Date Dec 15, 2014
Journal Monthly Notices of the Royal Astronomical Society
Print ISSN 0035-8711
Electronic ISSN 1365-2966
Publisher Royal Astronomical Society
Peer Reviewed Peer Reviewed
Volume 410
Issue 3
Pages 1993-2002
Keywords Cosmological parameters, Cosmology: observations, Dark energy, Distance scale, Large-scale structure of Universe.
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Published Journal Article (797 Kb)

Copyright Statement
This article has been accepted for publication in Monthly Notices of the Royal Astronomical Society © 2010 The Authors. Journal compilation © 2010 RAS. Published by Oxford University Press on behalf of the Royal Astronomical Society. All rights reserved.

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