MAPPING GROWTH AND GRAVITY WITH ROBUST REDSHIFT SPACE DISTORTIONS

Journal Article · Sun Apr 01 04:00:00 EDT 2012 · Astrophysical Journal

DOI:https://doi.org/10.1088/0004-637X/748/2/78· OSTI ID:22016130

Kwan, Juliana; Lewis, Geraint F ^[1]; Linder, Eric V ^[2]

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1. Sydney Institute for Astronomy, School of Physics, A28, University of Sydney, NSW 2006 (Australia)
2. Berkeley Lab, University of California, Berkeley, CA 94720 (United States)

Redshift space distortions (RSDs) 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{sup -1}. This bias propagates to estimates of the gravitational growth index as well as {Omega}{sub m} and the equation-of-state parameter and presents a significant challenge to modeling RSDs. We also determine an accurate fitting function for a combination of line-of-sight damping and higher order angular dependence that allows robust modeling of the redshift space power spectrum to substantially higher k.

• OSTI ID: 22016130
• Journal Information: Astrophysical Journal, Journal Name: Astrophysical Journal Journal Issue: 2 Vol. 748; ISSN ASJOAB; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
COMPUTERIZED SIMULATION
COSMOLOGICAL MODELS
COSMOLOGY
EQUATIONS OF STATE
GALAXIES
GENERAL RELATIVITY THEORY
GRAVITATION
PERTURBATION THEORY
RED SHIFT
SPECTRA
UNIVERSE