Choose to smooth: Gaussian streaming with the truncated Zel'dovich approximation

Abstract

We calculate the dark matter halo correlation function in redshift space using the Gaussian streaming model (GSM). To determine the scale dependent functions entering the streaming model we use local Lagrangian bias together with Convolution Lagrangian perturbation theory (CLPT) which constitutes an approximation to the Post-Zel'dovich approximation. On the basis of N-body simulations we demonstrate that a smoothing of the initial conditions with the Lagrangian radius improves the Zel'dovich approximation and its ability to predict the displacement field of proto-halos. Based on this observation we implement a "truncated" CLPT by smoothing the initial power spectrum and investigate the dependence of the streaming model ingredients on the smoothing scale. We find that the real space correlation functions of halos and their mean pairwise velocity are optimised if the coarse graining scale is chosen to be 1 Mpc/h at z=0, while the pairwise velocity dispersion is optimised if the smoothing scale is chosen to be the Lagrangian size of the halo. We compare theoretical results for the halo correlation function in redshift space to measurements within the Horizon Run 2 N-body simulation halo catalog. We find that this simple two-filter smoothing procedure in the spirit of the truncated Zel'dovich approximation significantly improves the GSM+CLPT prediction of the redshift space halo correlation function over the whole mass range from large galaxy to galaxy cluster-sized halos.

24 pages, 18 figures

References in corpus (15)

• Introducing the Illustris Project: the evolution of galaxy populations across cosmic time
• A test of the nature of cosmic acceleration using galaxy redshift distortions
• The 2dF-SDSS LRG and QSO Survey: The LRG 2-Point Correlation Function and Redshift-Space Distortions
• Nonlinear Perturbation Theory Integrated with Nonlocal Bias, Redshift-space Distortions, and Primordial Non-Gaussianity
• Detection of the kinematic Sunyaev-Zel'dovich effect with DES Year 1 and SPT
• Probing dark energy with cluster counts and cosmic shear power spectra: including the full covariance
• Baryon acoustic signature in the clustering of density maxima
• Lagrangian perturbations and the matter bispectrum I: fourth-order model for non-linear clustering
• Tests of redshift-space distortions models in configuration space for the analysis of the BOSS final data release
• Improving the modelling of redshift-space distortions: I. A bivariate Gaussian description for the galaxy pairwise velocity distributions
• Perturbation theory approach for the power spectrum: from dark matter in real space to massive haloes in redshift space
• Excursion Set Halo Mass Function and Bias in a Stochastic Barrier Model of Ellipsoidal Collapse
• Lagrangian perturbations and the matter bispectrum II: the resummed one-loop correction to the matter bispectrum
• sCOLA: The N-body COLA Method Extended to the Spatial Domain
• Coarse-grained cosmological perturbation theory: stirring up the dust model

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