Brane Decay and Defect Formation

TL;DR

This paper investigates how bulk fields affect the formation and evolution of topological defects in brane inflation models, revealing minimal impact on formation but significant influence on defect dynamics due to long-range interactions.

Contribution

The study introduces a toy model incorporating bulk fields into brane defect formation, highlighting their role in defect evolution rather than formation itself.

Findings

Bulk fields do not significantly alter defect formation.

Bulk fields induce long-range interactions among defects.

Defect evolution is strongly affected by bulk field interactions.

Abstract

Topological defects are generically expected to form in models of brane inflation. Brane-anti-brane annihilation provides a way to gracefully end inflation, and the dynamics of the tachyon field results in defect formation. The formation of defects has been studied mainly from the brane world-volume point of view, but the defects are themselves lower-dimensional branes, and as a result they couple to bulk fields. 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. In this toy model, we study the structure of defects and simulate their formation and evolution on a lattice. We find that while bulk fields do not have a significant effect on defect formation, they drastically influence the subsequent evolution of the defects, as they re-introduce long-range interactions between them.