Cosmological birefringence constraints from CMB and astrophysical
  polarization data
  Cosmological birefringence is a rotation of the polarization plane of photons
coming from sources of astrophysical and cosmological origin. The rotation can
also depend on the energy of the photons and not only on the distance of the
source and on the cosmological evolution of the underlying theoretical model.
In this work, we constrain few selected models for cosmological birefringence,
combining CMB and astrophysical data at radio, optical, X and gamma
wavelengths, taking into account the specific energy and distance dependences.
