Kahler potentials for Planck inflation

TL;DR

This paper investigates supergravity Kahler potentials that support viable single-field inflation models compatible with Planck data, emphasizing symmetry roles and string theory connections, and introduces a flexible supergravity inflation framework.

Contribution

It introduces a supergravity model adaptable to various inflationary potentials, including open and closed string inflation, unifying different models and highlighting symmetry roles.

Findings

Identifies Kahler potentials compatible with Planck constraints.

Proposes a supergravity inflation model for arbitrary potentials.

Connects supergravity models to string theory frameworks.

Abstract

We assess which Kahler potentials in supergravity lead to viable single-field inflationary models that are consistent with Planck. We highlight the role of symmetries, such as shift, Heisenberg and supersymmetry, in these constructions. Also the connections to string theory are pointed out. Finally, we discuss a supergravity model for arbitrary inflationary potentials that is suitable for open string inflation and generalize it to the case of closed string inflation. Our model includes the recently discussed supergravity reformulation of the Starobinsky model of inflation as well as an interesting alternative with comparable predictions.