Also just on the issue of cosmic variance. If you were trying to measure the true spatial curvature underlying of the universe, at and around the $10^{-5}$ level, on horizon scales you would be unable to separate contributions to it from inflationary perturbations because you only have one...
Hi all. As one of the authors of this paper I might be well placed to answer some of the questions about it.
As has been stated before this is just a short summary of calculations found in a longer paper that is currently at the advanced draft stage (we need to check for typos etc. and...