DR. L. SRIRAMKUMAR

In this talk, divided into two parts, the speaker will discuss the origin and the evolution of the scalar bispectrum during inflation and preheating in single field inflationary models. In the first part of the talk, after a brief outline of the so-called Maldacena formalism to evaluate the scalar bispectrum, he shall present an efficient and accurate method to numerically compute the scalar bispectrum and the non-Gaussianity parameter fnl in single field inflationary models involving the canonical scalar field. He shall also touch upon certain implications of the recent constraints on the parameter fnl from Planck on inflationary models. The second part of the talk focuses on the contributions to the bispectrum during the epoch of preheating, which immediately follows inflation. The speaker shall show that, in models involving a single scalar field wherein the potential behaves quadratically near the minimum, the contributions to the scalar bispectrum during preheating proves to be negligible.