Non-Gaussianities in the Extended EFT of Inflation

TL;DR

This paper explores non-Gaussianities in the Extended EFT of Inflation with high-derivative dispersion relations, analyzing the bispectrum, strong coupling constraints, and the shape of non-Gaussian features.

Contribution

It provides a detailed calculation of the bispectrum and non-Gaussianities in the EEFToI framework with $ ext{omega}^2 ext{propto} k^6$ dispersion relations, extending previous power spectrum analyses.

Findings

Identifies parameter regions where EEFToI with $ ext{omega}^2 ext{propto} k^6$ is valid and interesting.

Calculates the size and shape of non-Gaussianities in these regions.

Analyzes strong coupling constraints affecting the model's viability.

Abstract

In earlier works, we studied the validity of Extended Effective Field Theory of Inflation (EEFToI) in the regime where initial conditions are set with dispersion relations $\omega^2 \propto k^6$. We had also evaluated and examined the power spectrum for some interesting corners of the parameter space. In this paper, we compute the bispectrum in the EEFToI, take a closer look at the strong coupling constraints and calculate the size of the non-Gaussianities in those regions of parameter space. We also investigate the shape of triangles that contribute to the enhancement of non-Gaussianities in this regime. We find that there are allowed parts of parameter spaces where EEFToI description with initial conditions set with $\omega^2 \propto k^6$ is sensible and interesting.