Note on (D6,D8) Bound State, Massive Duality and Non-commutativity

TL;DR

This paper investigates a specific brane bound state in massive type IIA supergravity, exploring its supersymmetry, duality transformations, and implications for non-commutative gauge theories, highlighting the role of massive B-fields.

Contribution

It demonstrates how to generate the (D6,D8) bound state via massive T-duality from D7-branes and analyzes its supersymmetry and non-commutative limits.

Findings

The (D6,D8) bound state preserves 16 supersymmetries.

Massive T-duality can generate this bound state from D7-branes.

Seiberg-Witten limits lead to 9D non-commutative Yang-Mills theories.

Abstract

In this paper we study half-supersymmetric (D6,D8) bound state brane configuration of massive type IIA supergravity. We show that this bound state can also be generated by using massive T-duality rules of type-II supergravities in D=9, starting from D7-branes. We write down corresponding Killing spinors and find that these backgrounds indeed preserve 16 supersymmetries like any other D$p$-brane bound state with $B$-field. We also make a point on the massive nature of the $B$-field in this background. The Seiberg-Witten limits to obtain 9-dimensional NCYMs are also discussed, but the full understanding of such gauge theories remains unanswered.