Non-linear corrections to inflationary power spectrum

We study non-linear contributions to the power spectrum of the curvature perturbation on super-horizon scales, produced during slow-roll inflation driven by a canonical single scalar field. We find that on large scales the linear power spectrum completely dominates and leading non-linear corrections remain totally negligible, indicating that we can safely rely on linear perturbation theory to study inflationary power spectrum. We also briefly comment on the infrared and ultraviolet behaviour of the non-linear corrections.
Comment: (v1) 14 pages, 2 figures; (v2) references added and discussions expanded, including a new version of Figure 2, to appear in Journal of Cosmology and Astroparticle Physics