Mitigation of DESI fiber assignment incompleteness effect on two-point clustering with small angular scale truncated estimators

Understand

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.