Photon-photon interactions can be a source of CMB circular polarization

Abstract

Photon-photon interactions, as described by the standard Heisenberg-Euler interaction, can transform plane polarization of the CMB into circular polarization, in the period right after last scattering. We estimate the standard deviation of the resulting circular polarization parameter, as constrained by confining observations to angular regions of large plane polarization, and find results of the order of $10^{-9}$ for the Stokes parameter $V$.

Replaces 1205.4969, which was flawed beyond repair. 5 pages

Cited by in corpus (2)

• Physics Beyond The Standard Model with Circular Polarization in the CMB and CMB-21cm Cross-Correlation
• Generation of CMB B-mode Polarization from Circular Polarization