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arXiv · 1309.7473

A fast map-making preconditioner for regular scanning patterns

Sigurd Næss·Thibaut Louis
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Abstract

High-resolution Maximum Likelihood map-making of the Cosmic Microwave Background is usually performed using Conjugate Gradients with a preconditioner that ignores noise correlations. We here present a new preconditioner that approximates the map noise covariance as circulant, and show that this results in a speedup of up to 400% for a realistic scanning pattern from the Atacama Cosmology Telescope. The improvement is especially large for polarized maps.

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Sigurd Næss, Thibaut Louis. 2014-07-02. A fast map-making preconditioner for regular scanning patterns. https://doi.org/10.1088/1475-7516%2F2014%2F08%2F045

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