  The formation of the microwave background polarization anisotropies is
investigated when the stochastic Faraday rate is stationary, random and
Markovian. The scaling properties of the polarization power spectra and of
their nonlinear combinations are scrutinized as a function of the comoving
frequency. It is argued that each frequency channel of a given experiment
measuring simultaneously the E-mode and the B-mode spectra can be analyzed in
this framework with the aim of testing the physical origin of the polarization
in a model-independent perspective.
