Bispectrum-window convolution via Hankel transform. Issue 10 (1st October 2022)

• Record Type: Journal Article
• Authors: Pardede, Kevin; Rizzo, Federico; Biagetti, Matteo; Castorina, Emanuele; Sefusatti, Emiliano; Monaco, Pierluigi
• Is Part Of: Journal of cosmology and astroparticle physics. Volume 2022:Issue 10(2022)
• Publication Date: 2022-10-01
• Subjects: cosmological parameters from LSS -- galaxy clustering -- redshift surveys -- dark energy experiments; Cosmology -- Periodicals; Astrophysics -- Periodicals; 523.0105
• DOI: 10.1088/1475-7516/2022/10/066
• Languages: English
• ISSNs: 1475-7516

Abstract

Abstract: We present a method to perform the exact convolution of the model prediction for bispectrum multipoles in redshift space with the survey window function. We extend a widely applied method for the power spectrum convolution to the bispectrum, taking advantage of a 2D-FFTlog algorithm. As a preliminary test of its accuracy, we consider the toy model of a spherical window function in real space. This setup provides an analytical evaluation of the 3-point function of the window, and therefore it allows to isolate and quantify possible systematic errors of the method. We find that our implementation of the convolution in terms of a mixing matrix shows differences at the percent level in comparison to the measurements from a very large set of mock halo catalogs. It is also able to recover unbiased constraints on halo bias parameters in a likelihood analysis of a set of numerical simulations with a total volume of 100 h -3 Gpc 3 . For the level of accuracy required by these tests, the multiplication with the mixing matrix is performed in the time of one second or less.