Geometric constraints in dual F-theory and heterotic string compactifications

TL;DR

This paper explores the geometric constraints in dual F-theory and heterotic string compactifications, classifying models and revealing how F-theory insights inform heterotic bundle constructions, especially with exceptional structure groups.

Contribution

It provides a complete classification of dual models with specific geometric conditions, linking F-theory geometry to heterotic vector bundle stability and structure groups.

Findings

Classified dual F-theory/heterotic models with specific geometric conditions.

Identified topological constraints for heterotic bundles with exceptional groups.

Constructed all toric F-theory bases for certain dual models.

Abstract

We systematically analyze a broad class of dual heterotic and F-theory models that give four-dimensional supergravity theories, and compare the geometric constraints on the two sides of the duality. Specifically, we give a complete classification of models where the heterotic theory is compactified on a smooth Calabi-Yau threefold that is elliptically fibered with a single section and carries smooth irreducible vector bundles, and the dual F-theory model has a corresponding threefold base that has the form of a P^1 bundle. We formulate simple conditions for the geometry on the F-theory side to support an elliptically fibered Calabi-Yau fourfold. We match these conditions with conditions for the existence of stable vector bundles on the heterotic side, and show that F-theory gives new insight into the conditions under which such bundles can be constructed. In particular, we find that many allowed F-theory models correspond to vector bundles on the heterotic side with exceptional structure groups, and determine a topological condition that is only satisfied for bundles of this type. We show that in many cases the F-theory geometry imposes a constraint on the extent to which the gauge group can be enhanced, corresponding to limits on the way in which the heterotic bundle can decompose. We explicitly construct all (4962) F-theory threefold bases for dual F-theory/heterotic constructions in the subset of models where the common twofold base surface is toric, and give both toric and non-toric examples of the general results.