Modulated inflation from kinetic term

TL;DR

This paper investigates how kinetic term modulations influence inflationary perturbations, deriving analytic conditions for fluctuations and non-Gaussianity, and confirming results with the $ abla$-formula.

Contribution

It provides a detailed analytic framework for understanding modulated inflation from kinetic terms, including conditions for fluctuations and non-Gaussianity.

Findings

Analytic conditions for modulated fluctuations

Consistency between Mukhanov-Sasaki evolution and $ abla$-formula

Derived criteria for non-Gaussianity parameters

Abstract

We study modulated inflation from kinetic term. Using the Mukhanov-Sasaki variable, it is possible to determine how mixing induced by the kinetic term feeds the curvature perturbation with the isocurvature perturbation. We show explicitly that the analytic result obtained from the evolution of the Mukhanov-Sasaki variable is consistent with the $\delta N$-formula. From our results, we find analytic conditions for the modulated fluctuation and the non-Gaussianity parameter.