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Title: One-point remapping of Lagrangian perturbation theory in the mildly non-linear regime of cosmic structure formation

On the smallest scales, three-dimensional large-scale structure surveys contain a wealth of cosmological information which cannot be trivially extracted due to the non-linear dynamical evolution of the density field. Lagrangian perturbation theory (LPT) is widely applied to the generation of mock halo catalogs and data analysis. In this work, we compare topological features of the cosmic web such as voids, sheets, filaments and clusters, in the density fields predicted by LPT and full numerical simulation of gravitational large-scale structure formation. We propose a method designed to improve the correspondence between these density fields, in the mildly non-linear regime. We develop a computationally fast and flexible tool for a variety of cosmological applications. Our method is based on a remapping of the approximately-evolved density field, using information extracted from N-body simulations. The remapping procedure consists of replacing the one-point distribution of the density contrast by one which better accounts for the full gravitational dynamics. As a result, we obtain a physically more pertinent density field on a point-by-point basis, while also improving higher-order statistics predicted by LPT. We quantify the approximation error in the power spectrum and in the bispectrum as a function of scale and redshift. Our remapping procedure improvesmore » one-, two- and three-point statistics at scales down to 8 Mpc/h.« less
Authors:
; ;  [1] ;  [2]
  1. Institut d'Astrophysique de Paris (IAP), UMR 7095, CNRS - UPMC Université Paris 6, 98bis boulevard Arago, F-75014 Paris (France)
  2. Institute of Cosmology and Gravitation, University of Portsmouth, Dennis Sciama Building, Portsmouth PO1 3FX (United Kingdom)
Publication Date:
OSTI Identifier:
22369906
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Cosmology and Astroparticle Physics; Journal Volume: 2013; Journal Issue: 11; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; APPROXIMATIONS; COMPARATIVE EVALUATIONS; COMPUTERIZED SIMULATION; DATA ANALYSIS; DENSITY; GEOCHEMICAL SURVEYS; GEOPHYSICAL SURVEYS; LAGRANGIAN FUNCTION; PERTURBATION THEORY; STATISTICS; TOPOLOGY