Primordial Perturbation Has Non-Gaussianity?

Abstract

Non-Gaussianity in primordial density field provides a key probe of physics in early universe. Cosmic Microwave Background (CMB) measurement of WMAP satellite allows us to measure primordial non-Gaussianity in unprecedented accuracy. A possible detection of primordial non-Gaussianity shall rule out all of single field inflation models. Primordial non-Gaussianity has recently attracted much attention and has been studied in both theoretical and observational aspects. Here I review the current limits on the primordial non-Gaussianity from CMB measurements.