Venue: Maths 103
Inflationary predictions for the power spectrum of the curvature perturbation have been verified to an excellent degree, leaving many models compatible with observations. Higher-order correlations, if detected or constrained by Planck, will allow one to further distinguish between inflationary models. In this talk I will review the theory of gauge-invariant non-linear cosmological perturbations in the context of two-field inflation as well as the properties of the local bispectrum produced in these models. I will also present the methods I have developed and used for this purpose, which are the long-wavelength formalism and the cubic action of the adiabatic and isocurvature perturbations, and illustrate their use with explicit applications.