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FAST-PT II: an algorithm to calculate convolution integrals of general tensor quantities in cosmological perturbation theory

Authors :
Fang, Xiao
Blazek, Jonathan A.
McEwen, Joseph E.
Hirata, Christopher M.
Source :
JCAP 02(2017)030
Publication Year :
2016

Abstract

Cosmological perturbation theory is a powerful tool to predict the statistics of large-scale structure in the weakly non-linear regime, but even at 1-loop order it results in computationally expensive mode-coupling integrals. Here we present a fast algorithm for computing 1-loop power spectra of quantities that depend on the observer's orientation, thereby generalizing the FAST-PT framework (McEwen et al., 2016) that was originally developed for scalars such as the matter density. This algorithm works for an arbitrary input power spectrum and substantially reduces the time required for numerical evaluation. We apply the algorithm to four examples: intrinsic alignments of galaxies in the tidal torque model; the Ostriker-Vishniac effect; the secondary CMB polarization due to baryon flows; and the 1-loop matter power spectrum in redshift space. Code implementing this algorithm and these applications is publicly available at https://github.com/JoeMcEwen/FAST-PT .<br />Comment: 32 pages, 5 figures, 4 tables. Minor changes. Published in JCAP. Code available at https://github.com/JoeMcEwen/FAST-PT

Details

Database :
arXiv
Journal :
JCAP 02(2017)030
Publication Type :
Report
Accession number :
edsarx.1609.05978
Document Type :
Working Paper
Full Text :
https://doi.org/10.1088/1475-7516/2017/02/030