Mitigation of DESI fiber assignment incompleteness effect on two-point clustering with small angular scale truncated estimators
Abstract
We present a method to mitigate the effects of fiber assignment incompleteness in two-point power spectrum and correlation function measurements from galaxy spectroscopic surveys, by truncating small angular scales from estimators. We derive the corresponding modified correlation function and power spectrum windows to account for the small angular scale truncation in the theory prediction. We validate this approach on simulations reproducing the Dark Energy Spectroscopic Instrument (DESI) Data Release 1 (DR1) with and without fiber assignment. We show that we recover unbiased cosmological constraints using small angular scale truncated estimators from simulations with fiber assignment incompleteness, with respect to standard estimators from complete simulations. Additionally, we present an approach to remove the sensitivity of the fits to high modes in the theoretical power spectrum, by applying a transformation to the data vector and window matrix. We find that our method efficiently mitigates the effect of fiber assignment incompleteness in two-point correlation function and power spectrum measurements, at low computational cost and with little statistical loss.
Cite
@article{arxiv.2406.04804,
title = {Mitigation of DESI fiber assignment incompleteness effect on two-point clustering with small angular scale truncated estimators},
author = {M. Pinon and A. de Mattia and P. McDonald and E. Burtin and V. Ruhlmann-Kleider and M. White and D. Bianchi and A. J. Ross and J. Aguilar and S. Ahlen and D. Brooks and R. N. Cahn and E. Chaussidon and T. Claybaugh and S. Cole and A. de la Macorra and B. Dey and P. Doel and K. Fanning and J. E. Forero-Romero and E. Gaztañaga and S. Gontcho A Gontcho and C. Howlett and D. Kirkby and T. Kisner and A. Kremin and A. Lambert and M. Landriau and J. Lasker and L. Le Guillou and M. E. Levi and M. Manera and P. Martini and A. Meisner and R. Miquel and J. Moustakas and A. D. Myers and G. Niz and N. Palanque-Delabrouille and W. J. Percival and C. Poppett and G. Rossi and E. Sanchez and D. Schlegel and M. Schubnell and H. Seo and D. Sprayberry and G. Tarlé and M. Vargas-Magaña and B. A. Weaver and P. Zarrouk and R. Zhou and H. Zou},
journal= {arXiv preprint arXiv:2406.04804},
year = {2025}
}
Comments
36 pages, 23 figures. Small typos corrected, references added. Matches the published version