CMB anisotropies generated by a stochastic background of primordial magnetic fields with non-zero helicity
Abstract
We consider the impact of a stochastic background of primordial magnetic fields with non-vanishing helicity on CMB anisotropies in temperature and polarization. We compute the exact expressions for the scalar, vector and tensor part of the energy-momentum tensor including the helical contribution, by assuming a power-law dependence for the spectra and a comoving cutoff which mimics the damping due to viscosity. We also compute the parity-odd correlator between the helical and non-helical contribution which generate the TB and EB cross-correlation in the CMB pattern. We finally show the impact of including the helical term on the power spectra of CMB anisotropies up to multipoles with ℓ ~ 𝒪(103).
- Publication:
-
Journal of Cosmology and Astroparticle Physics
- Pub Date:
- October 2015
- DOI:
- 10.1088/1475-7516/2015/10/031
- arXiv:
- arXiv:1412.1836
- Bibcode:
- 2015JCAP...10..031B
- Keywords:
-
- Astrophysics - Cosmology and Nongalactic Astrophysics
- E-Print:
- 25 pages, 30 figures