Full metadata record
DC Field | Value | Language |
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dc.contributor.author | Uros Seljak | - |
dc.date.accessioned | 2016-08-28T12:08:02Z | - |
dc.date.available | 2016-08-28T12:08:02Z | - |
dc.date.issued | 2012 | - |
dc.identifier.issn | 1475-7516 | - |
dc.identifier.other | OAK-8548 | - |
dc.identifier.uri | https://dspace.ewha.ac.kr/handle/2015.oak/222436 | - |
dc.description.abstract | Measurement of redshift-space distortions (RSD) offers an attractive method to directly probe the cosmic growth history of density perturbations. A distribution function approach where RSD can be written as a sum over density weighted velocity moment correlators has recently been developed. In this paper we use results of N-body simulations to investigate the individual contributions and convergence of this expansion for dark matter. If the series is expanded as a function of powers of μ, cosine of the angle between the Fourier mode and line of sight, then there are a finite number of terms contributing at each order. We present these terms and investigate their contribution to the total as a function of wavevector k. For μ 2 the correlation between density and momentum dominates on large scales. Higher order corrections, which act as a Finger-of-God (FoG) term, contribute 1% at k ∼ 0.015hMpc -1, 10% at k ∼ 0.05hMpc -1 at z = 0, while for k > 0.15hMpc -1 they dominate and make the total negative. These higher order terms are dominated by density-energy density correlations which contributes negatively to the power, while the contribution from vorticity part of momentum density auto-correlation adds to the total power, but is an order of magnitude lower. For μ 4 term the dominant term on large scales is the scalar part of momentum density auto-correlation, while higher order terms dominate for k > 0.15hMpc -1. For μ 6 and μ 8 we find it has very little power for k < 0.15hMpc -1, shooting up by 2-3 orders of magnitude between k < 0.15hMpc -1 and k < 0.4hMpc -1. We also compare the expansion to the full 2-d P ss(k,μ), as well as to the monopole, quadrupole, and hexadecapole integrals of P ss(k,μ). For these statistics an infinite number of terms contribute and we find that the expansion achieves percent level accuracy for kμ < 0.15hMpc -1 at 6-th order, but breaks down on smaller scales because the series is no longer perturbative. We explore resummation of the terms into FoG kernels, which extend the convergence up to a factor of 2 in scale. We find that the FoG kernels are approximately Lorentzian with velocity dispersions around 600 km/s at z = 0. © 2012 IOP Publishing Ltd and SISSA. | - |
dc.language | English | - |
dc.title | Distribution function approach to redshift space distortions. Part II: N-body simulations | - |
dc.type | Article | - |
dc.relation.issue | 2 | - |
dc.relation.volume | 2012 | - |
dc.relation.index | SCIE | - |
dc.relation.index | SCOPUS | - |
dc.relation.journaltitle | Journal of Cosmology and Astroparticle Physics | - |
dc.identifier.doi | 10.1088/1475-7516/2012/02/010 | - |
dc.identifier.wosid | WOS:000301176000011 | - |
dc.identifier.scopusid | 2-s2.0-84857822645 | - |
dc.author.google | Okumura T. | - |
dc.author.google | Seljak U. | - |
dc.author.google | McDonald P. | - |
dc.author.google | Desjacques V. | - |
dc.contributor.scopusid | Uros Seljak(55508271200) | - |
dc.date.modifydate | 20230613102228 | - |