Heterotic Moduli Stabilization with Fractional Chern-Simons Invariants

TL;DR

This paper demonstrates that fractional fluxes from Wilson lines can stabilize all moduli in heterotic string compactifications on Calabi-Yau threefolds, leading to supersymmetric AdS vacua with potential relevance for realistic models.

Contribution

It introduces a novel mechanism using fractional Chern-Simons invariants from Wilson lines to stabilize moduli in heterotic string theory.

Findings

Fractional fluxes from Wilson lines stabilize moduli.

A supersymmetric AdS minimum exists at large volume and weak coupling.

The mechanism is compatible with realistic GUT models.

Abstract

We show that fractional flux from Wilson lines can stabilize the moduli of heterotic string compactifications on Calabi-Yau threefolds. We observe that the Wilson lines used in GUT symmetry breaking naturally induce a fractional flux. When combined with a hidden-sector gaugino condensate, this generates a potential for the complex structure moduli, Kahler moduli, and dilaton. This potential has a supersymmetric AdS minimum at moderately weak coupling and large volume. Notably, the necessary ingredients for this construction are often present in realistic models. We explore the type IIA dual phenomenon, which involves Wilson lines in D6-branes wrapping a three-cycle in a Calabi-Yau, and comment on the nature of the fractional instantons which change the Chern-Simons invariant.