Quasi-Single Field Inflation with Large Mass

TL;DR

This paper analyzes how a large-mass isocurvaton influences density perturbations in quasi-single field inflation, providing analytical corrections to the power spectrum for all mass values, especially in the large mass limit.

Contribution

It offers an exact analytical computation of the power spectrum correction for all isocurvaton masses, extending previous numerical results to larger masses.

Findings

Correction to the power spectrum scales as H^2/M^2 for large M

Analytical results confirm previous numerical findings for 0<M<3H/2

Provides a unified analytical approach for all isocurvaton masses

Abstract

We study the effect of massive isocurvaton on density perturbations in quasi-single field inflation models, when the mass of the isocurvaton M becomes larger than the order of the Hubble parameter H. We analytically compute the correction to the power spectrum, leading order in coupling but exact for all values of mass. This verifies the previous numerical results for the range 0<M<3H/2 and shows that, in the large mass limit, the correction is of order H^2/M^2.