  Large-scale magnetic fields affect the scalar modes of the geometry whose
ultimate effect is to determine the anisotropies of the Cosmic Microwave
Background (CMB in what follows). For the first time, a consistent numerical
approach to the magnetized CMB anisotropies is pursued with the aim of
assessing the angular power spectra of temperature and polarization when the
scalar modes of the geometry and a stochastic background of inhomogeneous
magnetic fields are simultaneously present in the plasma. The effects related
to the magnetized nature of the plasma are taken into account both at the level
of the dynamical equations and at the level of the initial conditions of the
Einstein-Boltzmann hierarchy. The temperature and polarization observables are
exploited to infer the peculiar signatures of a pre-equality magnetic field.
Using the extrapolated best fit to the three year WMAP data the increase and
distortions of the first seven peaks in the TT autocorrelations are monitored
for different values of the regularized magnetic field intensity and for the
physical range of spectral indices. Similar analyses are also conducted for the
first few anticorrelation (and corrrelation) peaks of the TE power spectra.
Possible interesting degeneracies and stimulating perspectives are pointed out
and explored.
