Non-Gaussianities in the Extended EFT of Inflation

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.

Comments: 30 pages, 5 figures, 3 tables (updated to match the published version)