This drop of course corresponds to a lack of large angle power in the polarization. However its form at low depends on geometric aspects of the projection from k to . In these models, the large angle polarization is dominated by projection aliasing of power from small scales . The asymptotic expressions of Eqn. Seeded models thus predict a more rapid reduction in the scalar polarization for the same background cosmology.
Polarization can also help separate the three types of fluctuations.
Differences also arise in the temperature-polarization cross power spectra shown in Fig. 9 . The sign test to distinguish scalars from tensors must thus be performed on scales larger than twice the first peak. Independent of the nature of the sources, the cross power at angles larger than that subtended by the horizon at last scattering is negative for the scalars and vectors and positive for the tensors. The more complex structure for the scalars at small angular scales reflects the correlation between the acoustic effective temperature and velocity at last scattering. Because of the late generation of metric fluctuations in these models, the peak in the polarization spectra is also shifted with x c .