Abstract

Cosmic microwave background provides valuable information on the origin of the Universe. Its two-point correlation function, i.e. power spectrum, has verified the basic predictions of the inflationary paradigm. Namely, the density perturbations that seed the large scale structure of the Universe are primordial, and they are approximately scale-invariant and Gaussian. Nonetheless, there are much more information in higher-point correlation functions, i.e. non-Gaussianities, which are the targets of many modern experiments. They encode the details of the inflationary dynamics, thus can help us to turn the paradigm into explicit models. In this talk, I will first review how various interacting dynamics during inflation can be associated with distinctive signatures in large primordial non-Gaussianities. Then I will introduce the concept of quasi-single field inflation models that predict a novel class of non-Gaussian signatures.