Cosmic microwave background polarization data and galactic foregrounds: estimation of cosmological parameters

We estimate the accuracy with which various cosmological parameters can be determined from the cosmic microwave background (CMB) temperature and polar ization data when various galactic unpolarized and polarized foregrounds ar e included and marginalized using the multi-frequency Wiener filtering tech nique. We use the specifications of the future CMB missions MAP and Planck for our study. Our results are in qualitative agreement with earlier result s obtained without foregrounds, though the errors in most parameters are hi gher because of degradation of the extraction of polarization signal in the presence of foregrounds.