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Small-Scale Cosmic Microwave Background Polarization from Reionization

Daniel Baumann·Asantha Cooray·Marc Kamionkowski
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Abstract

We discuss fluctuations in the cosmic microwave background (CMB) polarization due to scattering from reionized gas at low redshifts. Polarization is produced by re-scattering of the primordial temperature anisotropy quadrupole and of the kinematic quadrupole that arises from gas motion transverse to the line of sight. We show that both effects produce equal E- and B-parity polarization, and are, in general, several orders of magnitude below the dominant polarization contributions at the last scattering surface to E-modes or the gravitational-lensing contribution to B-modes at intermediate redshifts. These effects are also several orders of magnitude below the B polarization due to lensing even after subtraction with higher-order correlations, and are thus too small to constitute a background for searches for the polarization signature of inflationary gravitational waves.

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Daniel Baumann, Asantha Cooray, Marc Kamionkowski. 2002-08-28. Small-Scale Cosmic Microwave Background Polarization from Reionization. https://doi.org/10.1016/s1384-1076(03)00050-2

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