Modular Invariant Hilltop Inflation

TL;DR

This paper demonstrates that modular invariant theories can support successful hilltop inflation with the inflaton as a modulus field, utilizing gaugino condensation for stabilization and specific trajectory dynamics.

Contribution

It introduces a novel inflation model where the inflaton is a modulus field in a modular invariant framework, with stabilization via gaugino condensation.

Findings

Inflation begins near the fixed point τ = i and ends near τ = ω.

The inflationary trajectory is on the lower boundary of the fundamental domain.

Parameter space for successful inflation is identified.

Abstract

In this paper we show that it is possible to achieve successful hilltop inflation in which the inflaton is identified as the modulus field in a modular invariant theory. The dilaton plays a crucial role in shaping the potential. Modular invariant gaugino condensation provides the mechanism for the modulus stabilisation after inflation. The inflationary trajectory lies on the lower boundary of the fundamental domain of the modulus field $\tau$. Inflation starts near the fixed point $\tau ={\rm i}$, and ends at a point near $\tau = \omega$, which is the global de Sitter vacuum. We investigate the allowed parameter space for successful modular invariant hilltop inflation.