Understanding redshift space distortions in density-weighted peculiar velocity

Journal Article · Fri Jul 01 04:00:00 EDT 2016 · Journal of Cosmology and Astroparticle Physics

DOI:https://doi.org/10.1088/1475-7516/2016/07/001· OSTI ID:22679664

Sugiyama, Naonori S. ^[1]; Okumura, Teppei ^[2]

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1. Department of Physics, School of Science, The University of Tokyo, Tokyo 113-0033 (Japan)
2. Kavli Institute for the Physics and Mathematics of the Universe (WPI), Todai Institutes for Advanced Study, The University of Tokyo, Chiba 277-8582 (Japan)

Observations of the kinetic Sunyaev-Zel'dovich (kSZ) effect measure the density-weighted velocity field, a potentially powerful cosmological probe. This paper presents an analytical method to predict the power spectrum and two-point correlation function of the density-weighted velocity in redshift space, the direct observables in kSZ surveys. We show a simple relation between the density power spectrum and the density-weighted velocity power spectrum that holds for both dark matter and halos. Using this relation, we can then extend familiar perturbation expansion techniques to the kSZ power spectrum. One of the most important features of density-weighted velocity statistics in redshift space is the change in sign of the cross-correlation between the density and density-weighted velocity at mildly small scales due to nonlinear redshift space distortions. Our model can explain this characteristic feature without any free parameters. As a result, our results can precisely predict the non-linear behavior of the density-weighted velocity field in redshift space up to ∼ 30 h {sup -1} Mpc for dark matter particles at the redshifts of z =0.0, 0.5, and 1.0.

• OSTI ID: 22679664
• Journal Information: Journal of Cosmology and Astroparticle Physics, Journal Name: Journal of Cosmology and Astroparticle Physics Journal Issue: 07 Vol. 2016; ISSN 1475-7516
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
CORRELATION FUNCTIONS
CORRELATIONS
COSMOLOGY
DENSITY
DISTURBANCES
EXPANSION
NONLINEAR PROBLEMS
NONLUMINOUS MATTER
PERTURBATION THEORY
POWER DENSITY
RED SHIFT
SPACE
SPECTRA
STATISTICS
VELOCITY