Type IIA orientifold compactification on SU(2)-structure manifolds

TL;DR

This paper studies the effective low-energy theory of type IIA string theory compactified on six-dimensional SU(2)-structure manifolds with orientifold O6-planes, revealing a gauged N=2 supergravity with charged moduli.

Contribution

It provides the first detailed computation of the bosonic effective action for type IIA on SU(2)-structure orientifolds, showing the resulting theory is a constrained gauged N=2 supergravity.

Findings

The effective theory is a gauged N=2 supergravity with charged moduli.

Scalar target space is a quotient of specific coset spaces, constrained by origin from N=4 backgrounds.

All moduli in vector and hypermultiplets are charged in the effective theory.

Abstract

We investigate the effective theory of type IIA string theory on six-dimensional orientifold backgrounds with SU(2)-structure. We focus on the case of orientifolds with O6-planes, for which we compute the bosonic effective action in the supergravity approximation. For a generic SU(2)-structure background, we find that the low-energy effective theory is a gauged N=2 supergravity where moduli in both vector and hypermultiplets are charged. Since all these supergravities descend from a corresponding N=4 background, their scalar target space is always a quotient of a SU(1,1)/U(1) x SO(6,n)/SO(6)xSO(n) coset, and is therefore also very constrained.