Incorporating Backreaction in One-Loop Corrections in Ultra-Slow-Roll Inflation

TL;DR

This paper calculates one-loop quantum corrections to the primordial power spectrum in ultra-slow-roll inflation, demonstrating that backreaction effects cancel previously reported super-horizon corrections, highlighting their significance.

Contribution

It introduces a method to incorporate backreaction effects into one-loop corrections in USR inflation, showing their cancellation of super-horizon quantum corrections.

Findings

Backreaction cancels previously reported super-horizon corrections.

Backreaction effects are crucial for accurate quantum correction analysis.

The method improves understanding of quantum effects in USR inflation.

Abstract

We investigate the one-loop quantum correction to the power spectrum of primordial curvature perturbations in the ultra-slow-roll (USR) inflationary scenario, incorporating the backreaction effect from curvature perturbations. In the spatially-flat gauge, we expand the background inflaton field up to second order and identify the one-loop level backreaction term in the action. Utilizing a gauge transformation, we derive the comoving curvature interaction Hamiltonian in the presence of the backreaction term and calculate the one-loop correction using the in-in formalism. Our results reveal that the one-loop super-horizon corrections previously reported in the literature are canceled by the backreaction contributions. This finding underscores the importance of accounting for the backreaction effects in the analysis of quantum corrections during USR inflation.