Bibcode
Scóccola, Claudia; Harari, Diego; Mollerach, Silvia
Referencia bibliográfica
Physical Review D, vol. 70, Issue 6, id. 063003
Fecha de publicación:
9
2004
Revista
Número de citas
76
Número de citas referidas
68
Descripción
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 B0=10-9 G rotate E-modes
into B-modes with amplitude comparable to those due to the weak
gravitational lensing effect at frequencies around ν=30 GHz. The
strength of B-modes produced by Faraday rotation scales as
B0/ν2. We evaluate also the depolarizing effect
of Faraday rotation upon the cross correlation between temperature
anisotropy and E-type polarization.