A Note on D-brane - Anti-D-brane Interactions in Plane Wave Backgrounds

TL;DR

This paper investigates how D-brane and anti-D-brane interactions, especially the stringy halo phenomenon, are affected by the plane wave background with a mass parameter, revealing that the halo remains unchanged for Lorentzian branes but is altered for Euclidean branes.

Contribution

It provides the first analysis of the stringy halo in a plane wave background, showing its invariance for Lorentzian branes and modification for Euclidean branes due to the mass parameter.

Findings

The halo is unaffected by non-zero mu for Lorentzian branes.

The halo is affected by non-zero mu for Euclidean branes.

Implications for tachyon condensation and non-trivial vacua in plane wave backgrounds.

Abstract

We study aspects of the interaction between a D-brane and an anti-D-brane in the maximally supersymmetric plane wave background of type IIB superstring theory, which is equipped with a mass parameter mu. An early such study in flat spacetime (mu=0) served to sharpen intuition about D-brane interactions, showing in particular the key role of the ``stringy halo'' that surrounds a D-brane. The halo marks the edge of the region within which tachyon condensation occurs, opening a gateway to new non-trivial vacua of the theory. It seems pertinent to study the fate of the halo for non--zero mu. We focus on the simplest cases of a Lorentzian brane with p=1 and an Euclidean brane with p=-1, the D--instanton. For the Lorentzian brane, we observe that the halo is unaffected by the presence of non--zero mu. This most likely extends to other (Lorentzian) p. For the Euclidean brane, we find that the halo is affected by non-zero mu. As this is related to subtleties in defining the exchange amplitude between Euclidean branes in the open string sector, we expect this to extend to all Euclidean branes in this background.