Efficient Evaluation of Cosmological Angular Statistics

Understand

Angular statistics of cosmological observables are hard to compute.

• The main difficulty is due to the presence of highly-oscillatory Bessel functions which need to be integrated over.
• In this paper, we provide a simple and fast method to compute the angular power spectrum and bispectrum of any observable.
• The method is based on using an FFTlog algorithm to decompose the momentum-space statistics onto a basis of power-law functions.