Birefringence, CMB polarization and magnetized B-mode

Abstract

Even in the absence of a sizable tensor contribution, a B-mode polarization can be generated because of the competition between a pseudo-scalar background and pre-decoupling magnetic fields. By investigating the dispersion relations of a magnetoactive plasma supplemented by a pseudo-scalar interaction, the total B-mode polarization is shown to depend not only upon the plasma and Larmor frequencies but also on the pseudo-scalar rotation rate. If the (angular) frequency channels of a given experiment are larger than the pseudo-scalar rotation rate, the only possible source of (frequency dependent) B-mode autocorrelations must be attributed to Faraday rotation. In the opposite case the pseudo-scalar contribution dominates and the total rate becomes, in practice, frequency-independent. The B-mode cross-correlations can be used, under certain conditions, to break the degeneracy by disentangling the two birefringent contributions.

8 pages, 2 figures

References in corpus (14)

• Five-Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Cosmological Interpretation
• Five-Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Data Processing, Sky Maps, and Basic Results
• Five-Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Likelihoods and Parameters from the WMAP data
• Seven-Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Galactic Foreground Emission
• Correlation of CMB with large-scale structure: II. Weak lensing
• Five-Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Galactic Foreground Emission
• Second and third season QUaD CMB temperature and polarization power spectra
• New Measurements of Fine-Scale CMB Polarization Power Spectra from CAPMAP at Both 40 and 90 GHz
• Magnetized CMB observables: a dedicated numerical approach
• Faraday rotation, stochastic magnetic fields and CMB maps
• Tight coupling expansion and fully inhomogeneous magnetic fields
• Semi-analytical approach to magnetized temperature autocorrelations
• Transfer matrices for magnetized CMB anisotropies
• A magnetized completion of the $\Lambda$CDM paradigm

Cited by in corpus (11)

• New Constraints on the Primordial Magnetic Field
• Generation of circular polarization of the CMB
• Primordial Magnetism in the CMB: Exact Treatment of Faraday Rotation and WMAP7 Bounds
• Estimating relic magnetic fields from CMB temperature correlations
• Including birefringence into time evolution of CMB: current and future constraints
• Parameter dependence of magnetized CMB observables
• Large-Scale Magnetic Fields, Dark Energy and QCD
• Probing large-scale magnetism with the Cosmic Microwave Background
• Dark energy, integrated Sachs-Wolfe effect and large-scale magnetic fields
• Gradient expansion, curvature perturbations and magnetized plasmas
• Birefringence induced by pp-wave modes in an electromagnetically active dynamic aether