Priomordial non-Gaussian features from DBI Galileon inflation

TL;DR

This paper investigates the non-Gaussian features of primordial fluctuations generated during DBI Galileon inflation, analyzing bispectrum and trispectrum to understand their implications for early universe models.

Contribution

It provides a comprehensive calculation of the bispectrum and trispectrum in DBI Galileon inflation, revealing partial violation of known consistency relations and highlighting the potential for significant non-Gaussianities.

Findings

Computed bispectrum considering all scalar and tensor correlations.

Derived trispectrum including contact, scalar, and graviton exchange interactions.

Found partial violation of the Suyama-Yamaguchi relation, indicating large non-Gaussianities.

Abstract

We have studied primordial non-Gaussian features from a model of potential driven single field DBI Galileon inflation. We have computed the bispectrum from the three point correlation function considering all possible cross correlation between scalar and tensor modes from the proposed setup. Further, we have computed the trispectrum from four point correlation function considering the contribution from contact interaction, scalar and graviton exchange diagrams in the in-in picture. Finally we have obtained the non-Gaussian consistency conditions from the four point correlator, which results in partial violation of the Suyama-Yamaguchi four-point consistency relation. This further leads to the conclusion that sufficient primordial non-Gaussianities can be obtained from DBI Galileon inflation.