CMB anisotropies generated by a stochastic background of primordial magnetic fields with non-zero helicity

Journal Article · Thu Oct 01 00:00:00 EDT 2015 · Journal of Cosmology and Astroparticle Physics

DOI:https://doi.org/10.1088/1475-7516/2015/10/031· OSTI ID:22525243

Ballardini, Mario ^[1]; Finelli, Fabio; Paoletti, Daniela ^[2]

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1. DIFA, Dipartimento di Fisica e Astronomia, Alma Mater Studiorum, Università degli Studi di Bologna, viale Berti Pichat 6/2, I-40127 Bologna (Italy)
2. INAF/IASF-BO, Istituto di Astrofisica Spaziale e Fisica Cosmica di Bologna, via Gobetti 101, I-40129 Bologna (Italy)

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(10{sup 3})

• OSTI ID: 22525243
• Journal Information: Journal of Cosmology and Astroparticle Physics, Vol. 2015, Issue 10; Other Information: Country of input: International Atomic Energy Agency (IAEA); ISSN 1475-7516
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTROPHYSICS
COSMOLOGY AND ASTRONOMY
ANISOTROPY
ASTROPHYSICS
CORRELATIONS
DAMPING
ENERGY SPECTRA
ENERGY-MOMENTUM TENSOR
HELICITY
MAGNETIC FIELDS
MULTIPOLES
PARITY
POLARIZATION
RELICT RADIATION
SCALARS
STOCHASTIC PROCESSES
VECTORS
VISCOSITY