# CMB Constraints on a Stochastic Background of Primordial Magnetic Fields - Astrophysics > Cosmology and Nongalactic Astrophysics

CMB Constraints on a Stochastic Background of Primordial Magnetic Fields - Astrophysics > Cosmology and Nongalactic Astrophysics - Descarga este documento en PDF. Documentación en PDF para descargar gratis. Disponible también para leer online.

Abstract: We constrain a stochastic background of primordial magnetic field PMF byits contribution to the angular power spectrum of cosmic microwave backgroundanisotropies. We parametrize such stochastic background by a power-law spectrumwith index $n B$ and by its Gaussian smoothed amplitude $B \lambda$ on acomoving length $\lambda$. We give an approximation for the spectra of therelevant correlators of the energy-momentum of the stochastic background of PMFfor any $n B$. By using the WMAP 7 year data in combination with ACBAR, BICEPand QUAD we obtain the constraint $B {1 { m Mpc}} < 5.0$ nG at 95% confidencelevel for a stochastic background of non-helical PMF. We discuss the relativeimportance of the scalar and vector contribution to CMB anisotropies inobtaining these constraints. We then forecast {\sc Planck} capabilities inconstraining $B {1 { m Mpc}}$.

Autor: Daniela Paoletti, Fabio Finelli

Fuente: https://arxiv.org/