The V-mode polarization of the Cosmic Microwave Background
  The V-mode polarization of the Cosmic Microwave Background is discussed in a
weakly magnetized plasma. The VV and VT angular power spectra are computed for
adiabatic initial conditions of the Einstein-Boltzmann hierarchy. Depending
upon the frequency channel and upon the magnetic field intensity, the VT power
spectra of the circular polarization can even be seven orders of magnitude
larger than a putative B-mode polarization stemming from the lensing of the
primary anisotropies. Specific programs aimed at the direct detection of the
V-mode polarization of the Cosmic Microwave Background could provide a new
observational tool for the scrutiny of pre-decoupling physics.
