M-theory and Type IIA Flux Compactifications

TL;DR

This paper explores how to circumvent the supergravity no-go theorem in flux compactifications of M-theory and type IIA string theory, introducing new sources of brane charge and providing explicit supersymmetric examples.

Contribution

It identifies novel mechanisms for generating brane charges in flux compactifications, including higher derivative couplings in M-theory and transverse flux effects in string theory.

Findings

New sources of M5-brane charge from higher derivative couplings.

Explicit orientifold examples with N=1 and N=2 supersymmetry.

Discussion on the status of massive type IIA flux compactifications.

Abstract

We consider compactifications of M-theory and type IIA string theory to four dimensions. For Minkowski space-time, a supergravity no-go theorem forbids flux supported in the internal space. We show how to evade this no-go theorem by exhibiting new sources of brane charge: in string theory, the basic physical phenomenon is the generation of new brane charges from D-branes in transverse fluxes. In M-theory, there is a new source of M5-brane charge from novel higher derivative couplings that involve fluxes as well as curvatures. We present some explicit orientifold examples with both N=1 and N=2 space-time supersymmetry. Finally, we explain the status of massive type IIA flux compactifications.