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Fast Calculation of Nonlinear Redshift-space Galaxy Power Spectrum Including Selection Bias

Research paper by Joseph Tomlinson, Henry S. Grasshorn Gebhardt, Donghui Jeong

Indexed on: 09 Apr '20Published on: 07 Apr '20Published in: arXiv - Astrophysics - Cosmology and Nongalactic Astrophysics



Abstract

We present a fast implementation of the next-to-leading order (1-loop) redshift-space galaxy power spectrum by using FFTlog-based methods. [V. Desjacques, D. Jeong, and F. Schmidt, JCAP 1812 (12), 035] have shown that the 1-loop galaxy power spectrum in redshift space can be computed with 28 independent loop integrals with 22 bias parameters. Analytical calculation of the angular part of the loop integrals leaves the radial part in the form of a spherical Bessel transformation that is ready to be integrated numerically by using the FFTLog transformation. We find that the original 28 loop integrals can be solved with a total of 85 unique FFTLog transformations, yet leading to a few orders of magnitude speed up over traditional multi-dimensional integration. The code used in this work is publicly available at https://github.com/JosephTomlinson/GeneralBiasPk