On Brane Inflation With Volume Stabilization

TL;DR

This paper proposes a mechanism for brane inflation in string theory that maintains a flat inflaton potential through a shift symmetry linked to near BPS properties, ensuring volume stabilization.

Contribution

It introduces the 'inflaton trench' mechanism that preserves potential flatness in volume-stabilized brane inflation models via shift symmetry.

Findings

The 'inflaton trench' mechanism stabilizes the inflaton potential.

Shift symmetry related to near BPS conditions maintains flatness.

Applicable to models with stable volume compactification.

Abstract

The distance between BPS branes in string theory corresponds to a flat direction in the effective potential. Small deviations from supersymmetry may lead to a small uplifting of this flat direction and to brane inflation. However, this scenario can work only if the BPS properties of the branes and the corresponding flatness of the inflaton potential are preserved in the theories with the stable volume compactification. We present an ``inflaton trench'' mechanism that keeps the inflaton potential flat due to shift symmetry, which is related to near BPS symmetry in our model.