Cosmological Parameters from a re-analysis of the WMAP-7 low resolution
  maps
  Cosmological parameters from WMAP 7 year data are re-analyzed by substituting
a pixel-based likelihood estimator to the one delivered publicly by the WMAP
team. Our pixel based estimator handles exactly intensity and polarization in a
joint manner, allowing to use low-resolution maps and noise covariance matrices
in $T,Q,U$ at the same resolution, which in this work is 3.6$^\circ$. We
describe the features and the performances of the code implementing our
pixel-based likelihood estimator. We perform a battery of tests on the
application of our pixel based likelihood routine to WMAP publicly available
low resolution foreground cleaned products, in combination with the WMAP
high-$\ell$ likelihood, reporting the differences on cosmological parameters
evaluated by the full WMAP likelihood public package. The differences are not
only due to the treatment of polarization, but also to the marginalization over
monopole and dipole uncertainties implemented in the WMAP 7 year pixel
likelihood code for temperature. The credible central value for the
cosmological parameters change below the 1 $\sigma$ level with respect to the
evaluation by the full WMAP 7 year likelihood code, with the largest difference
in a shift to smaller values of the scalar spectral index $n_S$.
