On the bin sensitivity of the transverse BAO

Abstract

We investigate the transverse BAO projection effect caused by redshift binning uncertainty ($z_c$). For SKA HI and DESI LRG surveys, we compare Gaussian, top-hat, and semi-Gaussian bins over widths $0.01<{\sigma }_z<0.1$, and propose a statistical correction using adjacent redshifts. The semi-Gaussian bin best recovers the BAO signal for ${\sigma }_z<0.04$, despite higher shot noise. Constraints are survey-dependent: Gaussian binning is weakest for SKA, while for DESI semi-Gaussian is tightest for ${\sigma }_z<0.04$ (otherwise comparable). The semi-Gaussian scheme offers the optimal balance between cosmological parameter constraints and BAO fidelity, making it robust for multi-probe analyses.

arXiv commentAccepted for publication by JCAP. 35 pages, 27 figures