Ionization History of the Cosmic Plasma in the Light of the Recent Cosmic Background Imager and FuturePlanckData

This paper is devoted to the methods of the determination of cosmological parameters and distortions of ionization history from recent cosmic microwave background (CMB) observations. We show that the more complex models of kinetics of recombination with a few "missing" parameters describing the recombination process provide better agreement between the measured and the expected characteristics of the CMB anisotropy. In particular, we consider external sources of resonance and ionizing radiation and a model with strong clustering of the baryonic component. These factors can constrain the estimates of the cosmological parameters usually discussed. We also demonstrate that the measurements of the CMB polarization can improve these estimates and, for the precision expected from the Planck mission, allow the discrimination of a wide class of models.