On the evolution of non-Gaussianity
Mulryne, David (Queen Mary, University of London)

We study the evolution of of non-Gaussianity in multiple-field models of inflation. We discuss how particular features such as ridges and valleys can cause the magnitude of $\fnl$ to grow to significant values during the evolution, showing the expected sign of $\fnl$ in these cases and giving simple estimates for the peak value. Using numerical simulations as well as analytic arguments, we further discuss the fate of $\fnl$ as an adiabatic limit is reached. We consider a number of examples which illustrate different possibilities for when and how this limit is established -- including potentials which allow a natural convergence within the slow-roll phase, and potentials for which no natural convergence is possible and reheating is required to establish an adiabatic limit -- and which exhibit a large limiting value of non-Gaussianity.