Answers are grounded in this paper and cite their sources.
The results are given of accurate computations of the polarization of the cosmic micro-wave background radiation in homogenous anisotropic universes with flat spacelike hyper-surfaces. The degree of polarization never exceeds twice the maximum temperature quadrupole anisotropy, and its value is found to be very sensitive both to the mass fraction in the form of hydrogen and to its ionization history. There is no spectral distortion to first order.
No takes yet. Share an insight, caveat, or question.
Negroponte et al. (1980) studied this question.
Synapse has enriched 10 related papers. Consider them for comparative context: