Ghost D-brane, Supersymmetry and Matrix Model

TL;DR

This paper investigates the supersymmetric properties of ghost D-branes and their matrix models, demonstrating that pairs of D-branes and ghost D-branes preserve all 32 supersymmetries, including nonlinear ones, indicating a stable vacuum state.

Contribution

It introduces a matrix model for D-brane and ghost D-brane pairs, showing they preserve all supersymmetries and relate to the closed string vacuum, which is a novel insight.

Findings

The world volume theory has 32 unbroken supersymmetries.

Pairs of D-branes and ghost D-branes are equivalent to the closed string vacuum.

Half of the supersymmetries are nonlinearly realized.

Abstract

In this note we study the world volume theory of pairs of D-brane and ghost D-brane, which is shown to have 16 linear supersymmetries and 16 nonlinear supersymmetries. In particular we study a matrix model based on the pairs of D(-1)-brane and ghost D(-1)-brane. Since such pairs are supposed to be equivalent to the closed string vacuum, we expect all 32 supersymmetries should be unbroken. We show that the world volume theory of the pairs of D-brane and ghost D-brane has unbroken 32 supersymmetries even though a half of them are nonlinearly realized.