Non-Gaussianity in the Cosmic Microwave Background Anisotropies at Recombination in the Squeezed limit

Abstract

We estimate analytically the second-order cosmic microwave background temperature anisotropies at the recombination epoch in the squeezed limit and we deduce the contamination to the primordial local non-Gaussianity. We find that the level of contamination corresponds to f_NL^{con}=O(1) which is below the sensitivity of present experiments and smaller than the value O(5) recently claimed in the literature.

LaTeX file; 15 pages. Slightly revised version. Main result unchanged