Dynamically induced Planck scale and inflation in the Palatini formulation

TL;DR

This paper explores how adding an $R^2$ term in Palatini gravity allows non-minimal Coleman-Weinberg inflation to be consistent with observations by dynamically generating the Planck scale through the inflaton's vacuum expectation value.

Contribution

It demonstrates that the inclusion of an $R^2$ term in Palatini gravity restores compatibility of Coleman-Weinberg inflation with observational data.

Findings

The $R^2$ term enables dynamic Planck scale generation.

Inflation models become observationally viable with the $R^2$ addition.

The approach links vacuum expectation value to the Planck scale.

Abstract

We study non-minimal Coleman-Weinberg inflation in the Palatini formulation of gravity in the presence of an $R^2$ term. The Planck scale is dynamically generated by the vacuum expectation value of the inflaton via its non-minimal coupling to the curvature scalar $R$. We show that the addition of the $R^2$ term in Palatini gravity makes non-minimal Coleman-Weinberg inflation again compatible with observational data.