Mapping Growth and Gravity with Robust Redshift Space Distortions
Abstract
Redshift space distortions caused by galaxy peculiar velocities provide a window onto the growth rate of large scale structure and a method for testing general relativity. We investigate through a comparison of N-body simulations to various extensions of perturbation theory beyond the linear regime, the robustness of cosmological parameter extraction, including the gravitational growth index, \gamma. We find that the Kaiser formula and some perturbation theory approaches bias the growth rate by 1-sigma or more relative to the fiducial at scales as large as k > 0.07 h/Mpc. This bias propagates to estimates of the gravitational growth index as well as \Omega_m and the equation of state parameter and presents a significant challenge to modelling redshift space distortions. We also determine an accurate fitting function for a combination of line of sight damping and higher order angular dependence that allows robust modelling of the redshift space power spectrum to substantially higher k.
Keywords
Cite
@article{arxiv.1105.1194,
title = {Mapping Growth and Gravity with Robust Redshift Space Distortions},
author = {Juliana Kwan and Geraint F. Lewis and Eric V. Linder},
journal= {arXiv preprint arXiv:1105.1194},
year = {2015}
}
Comments
15 pages, 10 figures, changed to match version accepted for publication in ApJ