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arXiv · 2001.01757

Statistics of CMB polarization angles

James Creswell·Nadia Dachlythra·Hao Liu·Pavel Naselsky·Per Rex Christensen
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Abstract

We study the distribution functions of the CMB polarization angle $ψ$, focusing on the Planck 2018 CMB maps. We extend the model of Preece & Battye (2014) of Gaussian correlated $Q$ and $U$ Stokes parameters to allow nonzero means. When the variances of $Q$ and $U$ are equal and their covariance and means are zero, the polarization angle is uniformly distributed. Otherwise the uniform distribution will be modulated by harmonics with $2ψ$ and $4ψ$ phases. These modulations are visible in the Planck 2018 CMB maps. Furthermore, the mean value of $U$ is peculiar compared to the power spectrum.

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James Creswell, Nadia Dachlythra, Hao Liu, Pavel Naselsky, Per Rex Christensen. 2020-01-06. Statistics of CMB polarization angles. https://doi.org/10.1088/1475-7516%2F2020%2F02%2F001

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