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

Journal Article · Wed Feb 01 04:00:00 EST 2017 · Journal of Cosmology and Astroparticle Physics

DOI:https://doi.org/10.1088/1475-7516/2017/02/030· OSTI ID:22680025

Fang, Xiao; Blazek, Jonathan A.; McEwen, Joseph E.

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.

• OSTI ID: 22680025
• Journal Information: Journal of Cosmology and Astroparticle Physics, Journal Name: Journal of Cosmology and Astroparticle Physics Journal Issue: 02 Vol. 2017; ISSN 1475-7516
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
ALGORITHMS
BARYONS
COSMOLOGICAL MODELS
DENSITY
DISTURBANCES
GALAXIES
NONLINEAR PROBLEMS
PERTURBATION THEORY
POLARIZATION
RED SHIFT
RELICT RADIATION
SPACE
SPECTRA
STATISTICS
TENSORS
TORQUE