A numerical study of observational systematic errors in lensing analysis of CMB polarization

TL;DR

This paper uses numerical simulations to study how observational systematic errors like gain, angle, and pointing inaccuracies affect CMB polarization lensing analysis, showing that expected error levels won't significantly impair delensing.

Contribution

It provides a detailed numerical assessment of systematic errors' impact on CMB lensing and delensing, highlighting their effects on $B$-modes and reconstruction accuracy.

Findings

Systematic errors influence $B$-mode amplitude and scale.

Expected near-future error levels do not significantly degrade delensing.

Lensing reconstruction remains robust against typical systematic errors.

Abstract

Impacts of observational systematic errors on the lensing analysis of the cosmic microwave background (CMB) polarization are investigated by numerical simulations. We model errors of gain, angle, and pointing in observation of the CMB polarization and simulate polarization fields modulated by the errors. We discuss the response of systematics-induced $B$-modes to amplitude and spatial scale of the imposed errors and show that the results of the lensing reconstruction and delensing analysis behave according to it. It is observed that error levels expected in the near future lead to no significant degradation in delensing efficiency.