B polarization of the CMB from Faraday rotation

Journal Article · Wed Sep 15 04:00:00 EDT 2004 · Physical Review. D, Particles Fields

DOI:https://doi.org/10.1103/PhysRevD.70.063003· OSTI ID:20705191

Scoccola, Claudia; Harari, Diego; Mollerach, Silvia ^[1]

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1. Facultad de Ciencias Astronomicas y Geofisicas, Universidad Nacional de La Plata, Paseo del Bosque S/N, 1900 La Plata (Argentina)

We study the effect of Faraday rotation due to a uniform magnetic field on the polarization of the cosmic microwave background. Scalar fluctuations give rise only to parity-even E-type polarization of the cosmic microwave background. However in the presence of a magnetic field, a nonvanishing parity-odd B-type polarization component is produced through Faraday rotation. We derive the exact solution for the E and B modes generated by scalar perturbations including the Faraday rotation effect of a uniform magnetic field, and evaluate their cross correlations with temperature anisotropies. We compute the angular autocorrelation function of the B-modes in the limit that the Faraday rotation is small. We find that uniform primordial magnetic fields of present strength around B{sub 0}=10{sup -9} G rotate E-modes into B-modes with amplitude comparable to those due to the weak gravitational lensing effect at frequencies around {nu}=30 GHz. The strength of B-modes produced by Faraday rotation scales as B{sub 0}/{nu}{sup 2}. We evaluate also the depolarizing effect of Faraday rotation upon the cross correlation between temperature anisotropy and E-type polarization.

• OSTI ID: 20705191
• Journal Information: Physical Review. D, Particles Fields, Journal Name: Physical Review. D, Particles Fields Journal Issue: 6 Vol. 70; ISSN PRVDAQ; ISSN 0556-2821
• Country of Publication: United States
• Language: English

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
AMPLITUDES
ANISOTROPY
CORRELATIONS
COSMIC RADIATION
COSMOLOGY
DISTURBANCES
EXACT SOLUTIONS
FARADAY EFFECT
FLUCTUATIONS
GHZ RANGE
MAGNETIC FIELDS
PARITY
POLARIZATION
RADIOWAVE RADIATION
RELICT RADIATION
SCALARS