Large Non-Gaussianity in Non-Minimally Coupled Derivative Inflation with Gauss-Bonnet Correction

TL;DR

This paper investigates a nonminimal derivative inflation model with Gauss-Bonnet correction, analyzing its perturbations, non-Gaussian features, and observational constraints, revealing potential for large non-Gaussianity and blue-tilted spectra.

Contribution

It introduces a comprehensive analysis of nonminimal derivative inflation with Gauss-Bonnet term, including third-order perturbations and modified consistency relations, and compares results with observational data.

Findings

Model can produce large non-Gaussianity.

Some parameter ranges are consistent with Planck2015 data.

Predicts blue-tilted power spectrum in certain regimes.

Abstract

We study a nonminimal derivative inflationary model in the presence of the Gauss-Bonnet term. To have a complete treatment of the model, we consider a general form of the nonminimal derivative function and also the Gauss-Bonnet coupling term. By following the ADM formalism, expanding the action up to the third order in the perturbations and using the correlation functions, we study the perturbation and its non-Gaussian feature in details. We also study the consistency relation that gets modified in the presence of the Gauss-Bonnet term in the action. We compare the results of our consideration in confrontation with Planck2015 observational data and find some constraints on the model's parameters. Our treatment shows that this model in some ranges of the parameters is consistent with the observational data. Also, in some ranges of model's parameters, the model predicts blue-tilted power spectrum. Finally, we show that nonminimal derivative model in the presence of the GB term has capability to have large non-Gaussianity.