Dynamical realization of the small field inflation of Coleman-Weinberg type in the post supercooled universe

TL;DR

This paper introduces a dynamical trapping mechanism for small field inflation of Coleman-Weinberg type, utilizing ultra-supercooling to address initial condition tuning issues and align with observational bounds.

Contribution

It proposes a novel trapping mechanism using ultra-supercooling to naturally set initial conditions for CW-type small field inflation.

Findings

The mechanism successfully traps the inflaton at the false vacuum.

It allows the inflaton to start slow-roll dynamically.

The model is consistent with observational inflation bounds.

Abstract

The small field inflation (SFI) of Coleman-Weinberg (CW) type suffers from precise tuning of the initial inflaton field value to be away from the true vacuum one. We propose a dynamical trapping mechanism to solve this problem: an ultra-supercooling caused by an almost scale-invariant CW potential traps the inflaton at the false vacuum, far away from the true vacuum dominantly created by the quantum scale anomaly, and allows the inflaton to dynamically start the slow-roll down due to a classical explicit-scale breaking effect. To be concrete, we employ a successful CW-SFI model and show that the proposed mechanism works consistently with the observed bounds on the inflation parameters. The proposed new mechanism thus provides new insights for developing small field inflation models.