Gravitino Dark Matter from Inflaton Decay

TL;DR

This paper explores a scenario where gravitinos produced from inflaton decay serve as dark matter, with potential observational signatures in future QSO-galaxy lensing studies.

Contribution

It introduces a non-thermal gravitino dark matter model from inflaton decay applicable over a wide parameter space.

Findings

Gravitino dark matter can have a large free streaming length.

The scenario is consistent for a broad range of inflaton masses and VEVs.

Future observations could test this model through lensing effects.

Abstract

We discuss a scenario that gravitinos produced non-thermally by an inflaton decay constitute dark matter in the present universe. We find that this scenario is realized for wide ranges of the inflaton mass and the vacuum expectation value. What is intriguing about this scenario is that the gravitino dark matter can have a relatively large free streaming length at matter-radiation equality, which can be probed by future observation on QSO-galaxy strong lens system.