Monday, October 3 2016
14:00 - 15:00


Driving inflation and bounces with two field models

Rathul Nath

IMSc (DC Meeting)

In this talk, divided into two parts, I discuss inflationary and
bouncing scenarios driven by two scalar fields. I also discuss whether
features in the primordial spectrum can be consistent with small levels
of non-Gaussianities.

While numerical procedures have been constructed towards evaluating the
different three-point functions in single field inflationary models,
there has only been a limited effort in this direction in multi-field
scenarios. In the first part of the talk, I will begin by discussing our
work to evaluate the tensor bispectrum in two field models of inflation.
Following that, I will describe our efforts to study the effects of
transition from inflation driven by two field models to the epoch of
reheating. In this context, we are specifically investigating the
effects of such a transition on the evolution of large scale curvature
and iso-curvature perturbations. Lastly, I will also describe a
competing scenario wherein we are examining whether scalar and tensor
power spectra that are consistent with the observations can be generated
in bounces driven by two scalar fields.

It has been known for sometime now that certain features in the
primordial power spectrum can improve the fit to the CMB data.
Typically, these features are generated due to deviations from slow
roll, which also generally lead to higher levels of non-Gaussianities,
often beyond the current constraints. In the second part of my talk, I
will describe our efforts to generate features in the primordial
spectrum by modifying the initial quantum state and examining the
magnitude and shape of the resulting non-Gaussianities.

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