Gauge Five Brane Dynamics And Small Instanton Transitions In Heterotic Models

TL;DR

This paper constructs cosmological solutions in heterotic models with an evolving gauge five brane, providing insights into the dynamics after small instanton transitions without detailed microscopic descriptions.

Contribution

It presents the first cosmological solutions including an evolving bundle modulus in heterotic models, specifically modeling the post-transition evolution after small instanton events.

Findings

Certain properties of solutions are generic regardless of initial conditions.

An effective continuous matching of fields across the transition is not feasible due to low-energy theory constraints.

The solutions offer a way to understand post-transition dynamics despite the lack of microscopic detail.

Abstract

We present the first examples of cosmological solutions to four-dimensional heterotic models which include an evolving bundle modulus. The particular bundle modulus we consider corresponds to the width of a gauge five brane. As such our solutions can be used to describe the evolution in one of these models after a small instanton transition. We find that certain properties are generic to these solutions, regardless of initial conditions. This enables us to make some definite statements about the dynamics subsequent to a small instanton transition despite the fact that we cannot microscopically describe the process itself. We also show that an effective description of the small instanton transition by a continuous matching of fields and their first derivatives is precluded by the form of the respective low-energy theories before and after the transition.