Heterotic Strings with Torsion

TL;DR

This paper explores the duality between heterotic and type IIB string theories with fluxes, focusing on compactifications on non-Kahler manifolds with torsion, and provides explicit background solutions.

Contribution

It constructs explicit heterotic backgrounds with torsion and analyzes the constraints ensuring supersymmetry after dualities from type IIB flux compactifications.

Findings

Heterotic backgrounds with torsion are explicitly constructed.

Duality preserves supersymmetry in flux compactifications.

Constraints for non-Kahler manifolds with torsion are detailed.

Abstract

In this paper we describe the heterotic dual of the type IIB theory compactified to four dimensions on a toroidal orientifold in the presence of fluxes. The type IIB background is most easily described in terms of an M-theory compactification on a four-fold. The heterotic dual is obtained by performing a series of U-dualities. We argue that these dualities preserve supersymmetry and that the supergravity description is valid after performing them. The heterotic string is compactified on a manifold that is no longer Kahler and has torsion. These manifolds have to satisfy a number of constraints, for example, existence of an holomorphic three-form, size limits, torsional equations etc. We give an explicit form of the background and study the constraints associated to them.