Hybrid Inflation in Intersecting Brane Worlds

TL;DR

This paper explores the potential for hybrid inflation within intersecting brane world models in string theory, showing that slow-roll conditions are generally achievable and that inflation can end rapidly through open string tachyon-induced phase transitions.

Contribution

It demonstrates that intersecting brane worlds can naturally realize hybrid inflation scenarios with generic slow-roll conditions and a rapid end via tachyon condensation.

Findings

Slow-roll inflation is achievable in intersecting brane models.

Inflation ends nearly instantaneously due to open string tachyons.

Phase transition occurs via Higgs field condensation at brane intersections.

Abstract

Non-supersymmetric brane world scenarios in string theory display perturbative instabilities that usually involve run-away potentials for scalar moduli fields. We investigate in the framework of intersecting brane worlds whether the leading order scalar potential for the closed string moduli allows to satisfy the slow-rolling conditions required for applications in inflationary cosmology. Adopting a particular choice of basis in field space and assuming mechanisms to stabilize some of the scalars, we find that slow-rolling conditions can be met very generically. In intersecting brane worlds inflation can end nearly instantaneously like in the hybrid inflation scenario due to the appearance of open string tachyons localized at the intersection of two branes, which signal a corresponding phase transition in the gauge theory via the condensation of a Higgs field.