Influence on Starobinsky inflation by other fields with large amplitude

TL;DR

This paper investigates how a large-amplitude scalar field influences the dynamics of Starobinsky inflation, suggesting potential observable effects on CMB measurements if the field's amplitude approaches the Planck scale.

Contribution

It introduces the impact of a large expectation value scalar field on Starobinsky inflation dynamics, highlighting potential observational signatures.

Findings

Large scalar field amplitude can significantly alter inflation dynamics.

Effects may be detectable by future CMB experiments.

Influence depends on the field's amplitude relative to the Planck scale.

Abstract

The Starobinsky model is one of the inflation models consistent with the result of CMB observation by the Planck satellite. We consider the dynamics of the Starobinsky inflation in the presence of another scalar field with a large expectation value during inflation due to a negative Hubble-induced mass. We find that it would be affected if the other field has an amplitude close to the Planck scale. In this case, we may observe such effects on the Starobinsky model by future CMB experiments.