High precision simulations of weak lensing effect on Cosmic Microwave Background polarization

Abstract

We study accuracy, robustness and self-consistency of pixel-domain simulations of the gravitational lensing effect on the primordial CMB anisotropies due to the large-scale structure of the Universe. In particular, we investigate dependence of the results precision on some crucial parameters of such techniques and propose a semi-analytic framework to determine their values so the required precision is a priori assured and the numerical workload simultaneously optimized. Our focus is on the B-mode signal but we discuss also other CMB observables, such as total intensity, T, and E-mode polarization, emphasizing differences and similarities between all these cases. Our semi-analytic considerations are backed up by extensive numerical results. Those are obtained using a code, nicknamed lenS2HAT -- for Lensing using Scalable Spherical Harmonic Transforms (S2HAT) -- which we have developed in the course of this work. The code implements a version of the pixel-domain approach of Lewis (2005) and permits performing the simulations at very high resolutions and data volumes, thanks to its efficient parallelization provided by the S2HAT library -- a parallel library for a calculation of the spherical harmonic transforms. The code is made publicly available.

20 pages, 14 figures, submitted to A&A, matches version accepted for publication in A&A

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Cited by in corpus (18)

• Full covariance of CMB and lensing reconstruction power spectra
• CMB weak-lensing beyond the Born approximation: a numerical approach
• CMB lensing reconstruction biases in cross-correlation with large-scale structure probes
• Lensing Reconstruction in Post-Born Cosmic Microwave Background Weak Lensing
• The Accuracy of Weak Lensing Simulations
• Internal delensing of Cosmic Microwave Background polarization B-modes with the POLARBEAR experiment
• Impact of Polarized Galactic Foreground Emission on CMB Lensing Reconstruction and Delensing of B-Modes
• Maps of CMB lensing deflection from N-body simulations in Coupled Dark Energy Cosmologies
• Multiple Lensing of the Cosmic Microwave Background anisotropies
• MillimeterDL: Deep Learning Simulations of the Microwave Sky
• Comparison of delensing methodologies and assessment of the delensing capabilities of future experiments
• CMB lensing reconstruction biases from masking extragalactic sources
• Probing the statistical properties of CMB $B$-mode polarization through Minkowski Functionals
• Planck intermediate results. XLI. A map of lensing-induced B-modes
• Lensing simulations by Taylor expansion -- not so inefficient after all
• Detecting chiral gravity with the pure pseudospectrum reconstruction of the cosmic microwave background polarized anisotropies
• An algorithm for the numerical evaluation of the associated Legendre functions that runs in time independent of degree and order
• Cross-correlation of POLARBEAR CMB Polarization Lensing with High-$z$ Sub-mm Herschel-ATLAS galaxies