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SuperFaB: a fabulous code for Spherical Fourier-Bessel decomposition

Grasshorn Gebhardt, Henry S. and Doré, Olivier (2021) SuperFaB: a fabulous code for Spherical Fourier-Bessel decomposition. . (Unpublished)

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The spherical Fourier-Bessel (SFB) decomposition is a natural choice for the radial/angular separation that allows optimal extraction of cosmological information from large volume galaxy surveys. In this paper we develop a SFB power spectrum estimator that allows the measurement of the largest angular and radial modes with the next generation of galaxy surveys. The code measures the pseudo-SFB power spectrum, and takes into account mask, selection function, pixel window, and shot noise. We show that the local average effect is significant only in the largest-scale mode, and we provide an analytical covariance matrix. By imposing boundary conditions at the minimum and maximum radius encompassing the survey volume, the estimator does not suffer from the numerical instabilities that have proven challenging in the past. The estimator is demonstrated on simplified Roman-like, SPHEREx-like, and Euclid-like mask and selection functions. For intuition and validation, we also explore the SFB power spectrum in the Limber approximation. We release the associated public code written in Julia.

Item Type:Report or Paper (Discussion Paper)
Related URLs:
URLURL TypeDescription Paper
Grasshorn Gebhardt, Henry S.0000-0002-8158-0523
Doré, Olivier0000-0002-5009-7563
Additional Information:Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0). The authors thank Katarina Markovic, Christopher Hirata, Lado Samushia, Chen Heinrich, and the Nancy Grace Roman Telescope Cosmology with the High Latitude Survey Science Investigation Team (SIT) for discussions and providing selection functions and masks. Part of this work was done at Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration. This work was supported by NASA grant 15-WFIRST15-0008 Cosmology with the High Latitude Survey Roman Science Investigation Team (SIT). Henry S. G. Gebhardt’s research was supported by an appointment to the NASA Postdoctoral Program at the Jet Propulsion Laboratory, administered by Universities Space Research Association under contract with NASA.
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NASA Postdoctoral ProgramUNSPECIFIED
Subject Keywords:cosmology; large-scale structure
Record Number:CaltechAUTHORS:20210422-103123396
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Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:108802
Deposited By: Tony Diaz
Deposited On:23 Apr 2021 17:47
Last Modified:23 Apr 2021 17:47

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