2005/06/30 by David Seery, James E. Lidsey · 1 citation
Physics and Astronomy · #astro-ph #gr-qc #hep-th
paper · pdf · doi:10.1088/1475-7516/2005/09/011
published as JCAP0509:011,2005 · 24 pages, JCAP LaTeX style; replaced with version accepted by JCAP. Some corrections to Sections 2 and 5, conclusions unchanged
arxiv created 2005/09/21 · arxiv updated 2009/12/01
We calculate the three-point correlation function evaluated at horizon crossing for a set of interacting scalar fields coupled to gravity during inflation. This provides the initial condition for the three-point function of the curvature perturbation in the Sasaki--Stewart δN formulation. We find that the effect is small, of the order of a slow-roll parameter, and that the non-gaussianity can be determined on large scales once the unperturbed background evolution is known. As an example of the use of our formalism, we calculate the primordial non-gaussianity arising in a model of assisted inflation.