Recently WMAP and BOOMERanG experiments have set stringent constraints on the polarization angle of photons propagating in an expanding universe: Δα = (-2.41.9)°. The polarization of the Cosmic Microwave Background radiation (CMB) is reviewed in the context of nonlinear electrodynamics (NLED). We compute the polarization angle of photons propagating in a cosmological background with planar symmetry. For this purpose, we use the Pagels-Tomboulis (PT) Lagrangian density describing NLED, which has the form L ∼ (X/Λ4)δ-1X, where X = F αβFαβ, and δ the parameter featuring the non-Maxwellian character of the PT nonlinear description of the electromagnetic interaction. After looking at the polarization components in the plane orthogonal to the (x)-direction of propagation of the CMB photons, the polarization angle is defined in terms of the eccentricity of the universe, a geometrical property whose evolution on cosmic time (from the last scattering surface to the present) is constrained by the strength of magnetic fields over extragalactic distances.
|Titolo:||Nonlinear electrodynamics and CMB polarization|
|Autori interni:||LAMBIASE, Gaetano|
|Data di pubblicazione:||2011|
|Rivista:||JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS|
|Appare nelle tipologie:||1.1.1 Articolo su rivista con DOI|