More on Pre-Inflationary Non Gaussianities

TL;DR

This paper extends the analysis of non-Gaussianities in pre-inflationary cosmology to broader string-inspired models, examining their effects on curvature perturbations and graviton interactions within bounce scenarios.

Contribution

It generalizes the three-point amplitude calculations to a wider class of exponential potentials and includes graviton mode interactions, connecting string theory models with observable cosmological signatures.

Findings

E-fold ranges compatible with Planck data vary with potential steepness.

Three-point amplitudes show no special contributions from the bounce's turning point.

The analysis applies to models like SO(16)xSO(16) and related supersymmetry breaking scenarios.

Abstract

I generalize the three-point amplitude of curvature perturbations in the climbing scenario inspired by ten-dimensional non-supersymmetric strings to a broader class of exponential potentials, under some assumptions on the smoothing effects of String Theory that favor a bounce Cosmology. The extension can encompass the SO(16)xSO(16) model, together with other scenarios related to supersymmetry breaking in String Theory. The e-fold ranges compatible with Planck data move toward lower values of N for milder potentials and toward larger values for steeper ones. I also compute the three-point amplitudes involving graviton modes in the same bounce scenario, showing in detail their lack of peculiar contributions from the turning point.