Non-Gaussianities in Cosmological Perturbations and Inflation

Abstract

Primordial fluctuations are thought to be the origin of rich structures in the universe such as galaxies and clusters of galaxies. For this reason, generation of quantum fluctuations in the early universe is one of the most important research subjects in theoretical cosmology. In particular, motivated by forecasted detectability in the near future, non-Gaussianities in cosmological perturbations have been extensively studied in recent years. This article reviews non-Gaussianities in the early universe, based on the effective field theory of quantum fluctuations during cosmic inflation.