To the study of non-Gaussianity in two-field slow-roll inflation

Abstract

The general expression for the second order large scale curvature perturbation in the form of a functional over a background solution is derived. The explicit expressions was obtained for two special forms of the inflationary potential. In the considered cases, it is shown that a significant level of non-Gaussianity can be generated during the super-Hubble evolution only if nonadiabatic perturbations are non-negligible at the end of inflation.

arXiv comment15 pages,v2: more careful consideration in section 4, abstract and conclusion corrected, references added