Starobinsky Inflation: From Non-SUSY To SUGRA Realizations

TL;DR

This paper reviews how Starobinsky inflation can be realized within both non-SUSY and SUSY models, maintaining agreement with data, perturbative unitarity, and predicting an inflaton mass of 3x10^13 GeV.

Contribution

It introduces specific supergravity embeddings of Starobinsky inflation using gauge singlet superfields and symmetry-respecting Kaehler potentials, identifying stable configurations without higher order terms.

Findings

Inflation consistent with current data at subplanckian inflaton values.

Effective theories preserve perturbative unitarity up to the Planck scale.

Predicted inflaton mass is approximately 3x10^13 GeV.

Abstract

We review the realization of Starobinsky-type inflation within induced-gravity Supersymmetric (SUSY) and non-SUSY models. In both cases, inflation is in agreement with the current data and can be attained for subplanckian values of the inflaton. The corresponding effective theories retain perturbative unitarity up to the Planck scale and the inflaton mass is predicted to be 3x10^13 GeV. The supergravity embedding of these models is achieved by employing two gauge singlet chiral supefields, a superpotential that is uniquely determined by a continuous R and a discrete Zn symmetry, and several (semi)logarithmic Kaehler potentials that respect these symmetries. Checking various functional forms for the non-inflaton accompanying field in the Kaehler potentials, we identify four cases which stabilize it without invoking higher order terms.