2008/07/29 by Nishant Agarwal, Pankaj Jain, Douglas W. McKay +1
Physics and Astronomy · #Astrophysics and Cosmic Phenomena #Cosmology and Gravitation Theories #Dark Matter and Cosmic Phenomena #astro-ph #hep-ph
paper · pdf · doi:10.1103/physrevd.78.085028
published as Phys.Rev.D78:085028,2008 · 17 pages, 5 figures
arxiv created 2008/07/29 · openalex publication_date 2008/10/29 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/28
We study the effect of photon and ultralight pseudoscalar mixing on the propagation of electromagnetic radiation through the extragalactic medium. The medium is modeled as a large number of uncorrelated magnetic domains. We obtain an analytic expression for the different Stokes parameters in the limit of a small mixing angle. Stokes parameters are found to change linearly with the number of domains. We verify this result by direct numerical simulations. We use the formalism to estimate the effect of pseudoscalar-photon mixing on the cosmic microwave background (CMB) polarization. We impose limits on the model parameters consistent with CMB observations. We find that the currently allowed parameter range admits a CMB circular polarization up to order 10^\ensuremath-7.