A geometric bound on F-term inflation

TL;DR

This paper derives a geometric bound on F-term inflation in minimal supergravity, linking the feasibility of slow-roll inflation to the scalar manifold's geometry and supersymmetry breaking directions.

Contribution

It introduces a novel bound involving Kähler geometry and sGoldstini, clarifying constraints on realizing slow-roll inflation in F-term supergravity models.

Findings

The bound constrains single-field slow-roll inflation in F-term supergravity.

Inflationary models must satisfy geometric and supersymmetry-breaking conditions.

Implications for model building in supergravity inflation are discussed.

Abstract

We discuss a general bound on the possibility to realise inflation in any minimal supergravity with F-terms. The derivation crucially depends on the sGoldstini, the scalar field directions that are singled out by spontaneous supersymmetry breaking. The resulting bound involves both slow-roll parameters and the geometry of the K\"ahler manifold of the chiral scalars. We analyse the inflationary implications of this bound, and in particular discuss to what extent the requirements of single field and slow-roll can both be met in F-term inflation.