No-scale D-term inflation with stabilized moduli

TL;DR

This paper investigates the compatibility of D-term hybrid inflation with moduli stabilization, demonstrating its viability over F-term inflation and aligning with CMB data, while also constraining gravitino mass scales.

Contribution

It shows that D-term hybrid inflation can be consistently combined with moduli stabilization, unlike F-term inflation, and provides bounds on the gravitino mass in GUT-scale inflation.

Findings

F-term hybrid inflation is destabilized by tachyonic modes.

D-term hybrid inflation is compatible with moduli stabilization.

Gravitino mass bounds are established for GUT-scale inflation.

Abstract

We study the consistency of hybrid inflation and moduli stabilization, using the Kallosh--Linde model as an example for the latter. We find that F-term hybrid inflation is not viable since inflationary trajectories are destabilized by tachyonic modes. On the other hand, D-term hybrid inflation is naturally compatible with moduli stabilization due to the absence of a large superpotential term during the inflationary phase. Our model turns out to be equivalent to superconformal D-term inflation and it therefore successfully accounts for the CMB data in the large-field regime. Supersymmetry breaking can be incorporated via an O'Raifeartaigh model. For GUT-scale inflation one obtains stringent bounds on the gravitino mass. A rough estimate yields 10^5 GeV \lesssim m_3/2 \lesssim 10^10 GeV, contrary to naive expectation.