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Author Audren, Benjamin ♦ Lesgourgues, Julien
Source CERN Document Server
Content type Text
File Format PDF
Date Created 2011-06-15
Language English
Subject Domain (in DDC) Natural sciences & mathematics ♦ Physics ♦ Modern physics ♦ Technology ♦ Engineering & allied operations ♦ Applied physics
Subject Keyword Astrophysics and Astronomy
Abstract We address the issue of computing the non-linear matter power spectrum on mildly non-linear scales with efficient semi-analytic methods. We implemented M. Pietroni's Time Renormalization Group (TRG) method and its Dynamical 1-Loop (D1L) limit in a numerical module for the new Boltzmann code CLASS. Our publicly released module is valid for LCDM models, and optimized in such a way to run in less than a minute for D1L, or in one hour (divided by number of nodes) for TRG. A careful comparison of the D1L, TRG and Standard 1-Loop approaches reveals that results depend crucially on the assumed initial bispectrum at high redshift. When starting from a common assumption, the three methods give roughly the same results, showing that the partial resumation of diagrams beyond one loop in the TRG method improves one-loop results by a negligible amount. A comparison with highly accurate simulations by M. Sato & T. Matsubara shows that all three methods tend to over-predict non-linear corrections by the same amount on small wavelengths. Percent precision is achieved until k 0.2 h/Mpc for z>2, or until k 0.14 h/Mpc at z=1.
Description Presented at: JCAP 10 (2011) 037
Learning Resource Type Article
Publisher Date 2011-01-01
Rights License Preprint: © 2011-2018 CERN (License: CC-BY-3.0)
Page Count 24