Decomposing CMB lensing power with simulation

Abstract

The reconstruction of the CMB lensing potential is based on a Taylor expansion of lensing effects which is known to have poor convergence properties. For lensing of temperature fluctuations, an understanding of the higher order terms in this expansion which is accurate enough for current experimental sensitivity levels has been developed in Hanson et. al. (2010), as well as a slightly modified Okamoto and Hu quadratic estimator which incorporates lensed rather than unlensed spectra into the estimator weights to mitigate the effect of higher order terms. We extend these results in several ways: (1) We generalize this analysis to the full set of quadratic temperature/polarization lensing estimators, (2) We study the effect of higher order terms for more futuristic experimental noise levels, (3) We show that the ability of the modified quadratic estimator to mitigate the effect of higher order terms relies on a delicate cancellation which occurs only when the true lensed spectra are known. We investigate the sensitivity of this cancellation to uncertainties in or knowledge of these spectra. We find that higher order terms in the Taylor expansion can impact projected error bars at experimental sensitivities similar to those found in future ACTpol/SPTpol experiments.

References in corpus (2)

• A measurement of gravitational lensing of the microwave background using South Pole Telescope data
• CMB temperature lensing power reconstruction

Cited by in corpus (12)

• A bias to CMB lensing measurements from the bispectrum of large-scale structure
• Lensing Reconstruction in Post-Born Cosmic Microwave Background Weak Lensing
• On the effect of non-Gaussian lensing deflections on CMB lensing measurements
• Bias-Hardened CMB Lensing with Polarization
• Lensing reconstruction from a patchwork of polarization maps
• CMB lensing reconstruction using cut sky polarization maps and pure-$B$ modes
• A numerical study of observational systematic errors in lensing analysis of CMB polarization
• Simulations for 21 cm radiation lensing at EoR redshifts
• Imitating intrinsic alignments: A bias to the CMB lensing-galaxy shape cross-correlation power spectrum induced by the large-scale structure bispectrum
• Higher-Order Gravitational Lensing Reconstruction using Feynman Diagrams
• Approximate Likelihood Approaches for Detecting the Influence of Primordial Gravitational Waves in Cosmic Microwave Background Polarization
• Systematic effects on lensing reconstruction from a patchwork of CMB polarization maps