Intersecting 6-branes from new 7-manifolds with G_2 holonomy

TL;DR

This paper introduces a new family of 7-manifold metrics with G_2 holonomy, characterized by parameters and symmetries, which upon reduction yield intersecting D6-branes in type IIA string theory.

Contribution

It presents explicit new metrics of G_2 holonomy manifolds with specific isometries and singularity structures, connecting geometric parameters to D6-brane configurations.

Findings

Metrics depend on five parameters with two Abelian isometries.

Certain singularities correspond to fixed points of isometries.

Quantized parameters relate to the number of D6-branes.

Abstract

We discuss a new family of metrics of 7-manifolds with G_2 holonomy, which are R^3 bundles over a quaternionic space. The metrics depend on five parameters and have two Abelian isometries. Certain singularities of the G_2 manifolds are related to fixed points of these isometries; there are two combinations of Killing vectors that possess co-dimension four fixed points which yield upon compactification only intersecting D6-branes if one also identifies two parameters. Two of the remaining parameters are quantized and we argue that they are related to the number of D6-branes, which appear in three stacks. We perform explicitly the reduction to the type IIA model.