Fayet-Iliopoulos terms in supergravity and D-term inflation

TL;DR

This paper explores a new gauge-invariant Fayet-Iliopoulos term in supergravity, demonstrating its compatibility with matter fields and its potential to drive observable D-term inflation consistent with cosmological data.

Contribution

It introduces a consistent framework for incorporating a new FI term in supergravity inflation models with matter fields and analyzes its implications for inflation dynamics.

Findings

Charged matter fields can be added with the new FI term in supergravity.

Inflation driven by a D-term with two FI parameters can satisfy slow-roll conditions.

The model predicts an observable tensor-to-scalar ratio compatible with current cosmological constraints.

Abstract

We analyse the consequences of a new gauge invariant Fayet-Iliopoulos (FI) term proposed recently to a class of inflation models driven by supersymmetry breaking with the inflaton being the superpartner of the goldstino. We first show that charged matter fields can be consistently added with the new term, as well as the standard FI term in supergravity in a K\"ahler frame where the $U(1)$ is not an R-symmetry. We then show that the slow-roll conditions can be easily satisfied with inflation driven by a D-term depending on the two FI parameters. Inflation starts at initial conditions around the maximum of the potential where the $U(1)$ symmetry is restored and stops when the inflaton rolls down to the minimum describing the present phase of our Universe. The resulting tensor-to-scalar ratio of primordial perturbations can be even at observable values in the presence of higher order terms in the K\"ahler potential.