Skip to main content

Research Repository

Advanced Search

Modelling redshift space distortions in hierarchical cosmologies

Jennings, Elise; Baugh, Carlton M.; Pascoli, Silvia

Modelling redshift space distortions in hierarchical cosmologies Thumbnail


Elise Jennings


The anisotropy of clustering in redshift space provides a direct measure of the growth rate of large-scale structure in the Universe. Future galaxy redshift surveys will make high-precision measurements of these distortions, and will potentially allow us to distinguish between different scenarios for the accelerating expansion of the Universe. Accurate predictions are needed in order to distinguish between competing cosmological models. We study the distortions in the redshift space power spectrum in Lambda cold dark matter (ΛCDM) and quintessence dark energy models, using large-volume N-body simulations, and test predictions for the form of the redshift space distortions. We find that the linear perturbation theory prediction is a poor fit to the measured distortions, even on surprisingly large scales k≥ 0.05 h Mpc−1. An improved model for the redshift space power spectrum, including the non-linear velocity divergence power spectrum, is presented and agrees with the power spectra measured from the simulations up to k∼ 0.2 h Mpc−1. We have found a density–velocity relation which is cosmology independent and which relates the non-linear velocity divergence spectrum to the non-linear matter power spectrum. We provide a formula which generates the non-linear velocity divergence P(k) at any redshift, using only the non-linear matter power spectrum and the linear growth factor at the desired redshift. This formula is accurate to better than 5 per cent on scales k < 0.2 h Mpc−1 for all the cosmological models discussed in this paper. Our results will extend the statistical power of future galaxy surveys.


Jennings, E., Baugh, C. M., & Pascoli, S. (2011). Modelling redshift space distortions in hierarchical cosmologies. Monthly Notices of the Royal Astronomical Society, 410(3), 2081-2094.

Journal Article Type Article
Publication Date Jan 1, 2011
Deposit Date Jan 31, 2012
Publicly Available Date Apr 28, 2015
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 2081-2094
Keywords Methods: numerical, Cosmology: theory, Large-scale structure of Universe.


Published Journal Article (1.6 Mb)

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.

You might also like

Downloadable Citations