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Other version: http://stacks.iop.org/14757516/2014/i=05/a=003?key=crossref.2c4d98fae4ad1ca38083738c54e59320
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Title 
Peculiar velocities in redshift space: formalism, Nbody simulations and perturbation theory 

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Published in  Journal of Cosmology and Astroparticle Physics. 2014, vol. 05, no. 003, p. 45  
Abstract  Direct measurements of peculiar velocities of galaxies and clusters of galaxies can in principle provide explicit information on the three dimensional mass distribution, but this information is modulated by the fact that velocity field is sampled at galaxy positions, and is thus probing galaxy momentum. We derive expressions for the cross power spectrum between the density and momentum field and the auto spectrum of the momentum field in redshift space, by extending the distribution function method to these statistics. The resulting momentum cross and auto power spectra in redshift space are expressed as infinite sums over velocity moment correlators in real space, as is the case for the density power spectrum in redshift space. We compute each correlator using Eulerian perturbation theory (PT) and halo biasing model and compare the resulting redshiftspace velocity statistics to those measured from Nbody simulations for both dark matter and halos. We find that in redshift space linear theory predictions for the densitymomentum cross power spectrum as well as for the momentum auto spectrum fail to predict the Nbody results at very large scales. On the other hand, our nonlinear PT prediction for these velocity statistics, together with realspace power spectrum for dark matter from simulations, improves the accuracy for both dark matter and halos. We also present the same analysis in configuration space, computing the redshiftspace pairwise mean infall velocities and velocity correlation function and compare to nonlinear PT.  
Keywords  Redshift surveys — Galaxy clustering — Cosmological perturbation theory — Power spectrum  
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Citation (ISO format)  OKUMURA, Teppei et al. Peculiar velocities in redshift space: formalism, Nbody simulations and perturbation theory. In: Journal of Cosmology and Astroparticle Physics, 2014, vol. 05, n° 003, p. 45. https://archiveouverte.unige.ch/unige:40526 