Dark energy, integrated Sachs-Wolfe effect and large-scale magnetic
  fields
  The impact of large-scale magnetic fields on the interplay between the
ordinary and integrated Sachs-Wolfe effects is investigated in the presence of
a fluctuating dark energy component. The modified initial conditions of the
Einstein-Boltzmann hierarchy allow for the simultaneous inclusion of dark
energy perturbations and of large-scale magnetic fields. The temperature and
polarization angular power spectra are compared with the results obtained in
the magnetized version of the (minimal) concordance model. Purported
compensation effects arising at large scales are specifically investigated. The
fluctuating dark energy component modifies, in a computable manner, the shapes
of the 1- and 2-$\sigma$ contours in the parameter space of the magnetized
background. The allowed spectral indices and magnetic field intensities turn
out to be slightly larger than those determined in the framework of the
magnetized concordance model where the dark energy fluctuations are absent.
