Defect Formation with Bulk Fields

TL;DR

This paper investigates how interactions with bulk fields affect defect formation during brane-antibrane annihilation, finding that bulk-brane coupling influences defect properties but does not prevent defect network formation.

Contribution

It introduces a toy model to study the impact of bulk fields on defect formation and evolution in brane-antibrane systems, highlighting the role of extra dimensions and couplings.

Findings

Bulk-brane coupling influences defect energetics and interactions.

Defect networks still form despite bulk interactions.

Size of extra dimensions affects defect properties.

Abstract

It has recently been realized that brane-antibrane annihilation (a possible explanation for ending inflation) may result in defect formation, due to the dynamics of the tachyon field. Studies of this possibility have generally ignored the interaction of the brane fields with fields in the bulk; recently it has been argued [1] that interactions with bulk fields suppress or even eliminate defect formation. To investigate the impact of bulk fields on brane defect formation, we construct a toy model that captures the essential features of the tachyon condensation with bulk fields. We study the structure of defects in this toy model, and simulate their formation and evolution on the lattice. We find that, while the energetics and interactions of defects are influenced by the size of the extra dimension and the bulk-brane coupling, the bulk-brane coupling does not prevent the formation of a defect network.