Hilltop Supernatural Inflation and Gravitino Problem

In this paper, we explore the parameter space of hilltop supernatural inflation model and show the regime within which there is no gravitino problem even if we consider both thermal and nonthermal production mechanisms. We make plots for the allowed reheating temperature as a function of gravitino mass by constraints from big-bang nucleosynthesis. We also plot the constraint when gravitino is assumed to be stable and plays the role of dark matter.

💡 Research Summary

The paper investigates the viability of hilltop supernatural inflation in the context of the gravitino problem, addressing both thermal and non‑thermal production mechanisms. Hilltop supernatural inflation is a variant of supersymmetric hybrid inflation in which the inflaton potential possesses a maximum (“hilltop”) near the origin, allowing successful inflation even when the field starts at small values. The authors adopt a generic potential of the form
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