FFTLog-and-beyond: Generalized FFTLog algorithm
Abstract
FFTLog-and-beyond takes the FFTLog algorithm for single-Bessel integrals and generalizes it for integrals containing a derivative of the Bessel function to solve the non-Limber integrals. The full non-Limber angular power spectrum integral is simplified by noting the small contribution from unequal-time nonlinear terms; this significantly reduces the computation and avoids the double-Bessel integral. The original FFTLog algorithm is also extended to compute integrals containing derivatives of Bessel functions, which can be used to efficiently compute angular power spectra including redshift-space distortions (RSD) and Doppler effects. C and Python versions of the code are available.
- Publication:
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Astrophysics Source Code Library
- Pub Date:
- November 2019
- Bibcode:
- 2019ascl.soft11022F
- Keywords:
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- Software