When the cosmic microwave photons scatter electrons just prior to the
decoupling of matter and radiation, magnetic fields do contribute to the Stokes
matrix as well as to the scalar, vector and tensor components of the transport
equations for the brightness perturbations. The magnetized electron-photon
scattering is hereby discussed in general terms by including, for the first
time, the contribution of magnetic fields with arbitrary direction and in the
presence of the scalar, vector and tensor modes of the geometry. The
propagation of relic vectors and relic gravitons is discussed for a varying
magnetic field orientation and for different photon directions. The source
terms of the transport equations in the presence of the relativistic
fluctuations of the geometry are also explicitly averaged over the magnetic
field orientations and the problem of a consistent account of the small-scale
and large-scale magnetic field is briefly outlined.Comment: 32 pages, 3 figure
