Talk by Dr. V. Sreenath, LSU

Talk by Dr. V. Sreenath

Speaker: Dr. V. Sreenath, LSU

Title: Computation and characteristics of inflationary three-point functions
Time: 11:00 Wednesday August 26 2015
Place: 241 Nicholson

Abstract:

In this talk, divided into two parts, I shall describe our efforts to numerically evaluate the inflationary three-point functions (which evidently include, apart from the oft-considered scalar bi-spectrum, the cross-correlations involving scalars and tensors as well as the tensor bi-spectrum), and also discuss the consistency relations obeyed by all the three-point functions. In the first part of the talk, I shall outline the numerical procedure we have constructed, based on the Maldacena formalism, to compute the three-point functions in single field inflationary models involving the canonical scalar field. After introducing dimensionless non-Gaussianity parameters to characterize the scalar-tensor cross-correlations, I shall utilize the numerical code to study the behavior of non-Gaussianity parameters describing all the three-point functions in three types of inflationary models which contain departures from slow roll and lead to power spectra with features that result in an

improved fit to the CMB data. In the second part of the talk, following a sketch of the derivation of the consistency relations, I shall express the consistency relations in terms of the non-Gaussianity parameters and explicitly examine (analytically as well as numerically) the validity of these relations away from slow roll. I shall illustrate that the consistency conditions hold true even in scenarios consisting of strong departures from slow roll.