PUB - Publikationen an der Universität Bielefeld

We calculate the power spectra of primordial curvature and isocurvatureperturbations from a general two field inflation model at next-to-leading ordercorrection in a slow-roll expansion. In particular we calculate the spectralindices to second order in slow-roll parameters. We show that thecross-correlation of the curvature and isocurvature perturbations at the timeof Hubble-exit during inflation is non-zero at first-order in slow-rollparameters. We apply our results to different classes of inflation, includinginflaton and curvaton scenarios. The spectrum of primordial gravitationalwaves, curvature and isocurvature perturbations obey generalised consistencyrelations in two-field inflation models. We give the first two consistencyrelations in an infinite hierarchy.