Enhanced Gauge Symmetries and Calabi-Yau Threefolds

TL;DR

This paper explores how nonabelian gauge symmetries in type IIA string theory on Calabi-Yau manifolds are explained through string-string duality with heterotic strings, highlighting the nonperturbative origins of these symmetries.

Contribution

It demonstrates that nonabelian gauge symmetries appearing nonperturbatively in type IIA are a consequence of string duality, providing explicit examples and insights into their origin.

Findings

Nonabelian gauge symmetries are duality-induced in type IIA strings.

Symmetries are perturbative in heterotic string descriptions.

Examples illustrate the duality relationship and symmetry emergence.

Abstract

We consider the general case of a type IIA string compactified on a Calabi-Yau manifold which has a heterotic dual description. It is shown that the nonabelian gauge symmetries which can appear nonperturbatively in the type II string but which are understood perturbatively in the heterotic string are purely a result of string-string duality in six dimensions. We illustrate this with some examples.