Fast CMB lensing using statistical interpolation on the sphere

Abstract

We describe a accurate and fast pixel-based statistical method to interpolate fields of arbitrary spin on the sphere. We call this method Fast and Lean Interpolation on the Sphere (FLINTS). The method predicts the optimal interpolated values based on the theory of isotropic Gaussian random fields and provides an accurate error estimate at no additional cost. We use this method to compute lensed Cosmic Microwave Background (CMB) maps precisely and quickly, achieving a relative precision of 0.02% at a HEALPix resolution of Nside=4096, for a bandlimit of l_max=4096 in the same time it takes to simulate the original, unlensed CMB map. The method is suitable for efficient, distributed memory parallelization. The power spectra of our lensed maps are accurate to better than 0.5% at l=3000 for the temperature, the E and B mode of the polarization. As expected theoretically, we demonstrate that, on realistic cases, this method is between two to three orders of magnitude more precise than other known interpolation methods for the same computational cost.

13 pages, 8 figures, published by ApJS

References in corpus (18)

• HEALPix -- a Framework for High Resolution Discretization, and Fast Analysis of Data Distributed on the Sphere
• Efficient Computation of CMB anisotropies in closed FRW models
• An All-Sky Analysis of Polarization in the Microwave Background
• CMB Anisotropies: Total Angular Momentum Method
• Detection of Gravitational Lensing in the Cosmic Microwave Background
• A limit on the detectability of the energy scale of inflation
• Likelihood Analysis of CMB Temperature and Polarization Power Spectra
• Separation of Gravitational-Wave and Cosmic-Shear Contributions to Cosmic Microwave Background Polarization
• Determining Neutrino Mass from the CMB Alone
• Correlation of CMB with large-scale structure: II. Weak lensing
• Lensed CMB power spectra from all-sky correlation functions
• Lensed CMB simulation and parameter estimation
• Probing neutrino masses with CMB lensing extraction
• Neutrino Mass and Dark Energy from Weak Lensing
• Cosmological Information from Lensed CMB Power Spectra
• Cross-correlation of CMB with large-scale structure: weak gravitational lensing
• A Large Sky Simulation of the Gravitational Lensing of the Cosmic Microwave Background
• What can be learned from the lensed cosmic microwave background B-mode polarization power spectrum?

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• Bayesian delensing of CMB temperature and polarization
• CMB-S4: Iterative Internal Delensing and $r$ Constraints
• Improved cosmic microwave background (de-)lensing using general spherical harmonic transforms
• Lensing Simulation and Power Spectrum Estimation for High Resolution CMB Polarization Maps
• High precision simulations of weak lensing effect on Cosmic Microwave Background polarization
• Comparison of delensing methodologies and assessment of the delensing capabilities of future experiments
• Optimal bispectrum estimator and simulations of the the CMB Lensing-ISW non-Gaussian signal
• Lensing simulations by Taylor expansion -- not so inefficient after all