Strings between branes

TL;DR

This paper constructs classical solutions in Yang-Mills theory representing D-branes with fundamental strings stretching between them, providing insights into string junctions, networks, and tachyon condensation.

Contribution

It introduces a non-abelian Yang-Mills framework to model fundamental strings between D-branes and analyzes related monopoles, offering a new classical perspective on string configurations.

Findings

String charge density supported between D-branes

Smooth resolutions of string junctions and networks

Insights into tachyon condensation in Yang-Mills limit

Abstract

D-brane configurations containing fundamental strings are constructed as classical solutions of Yang-Mills theory. The fundamental strings in these systems stretch between D-branes. In the case of D1-branes, this construction gives smooth (classical) resolutions of string junctions and string networks. Using a non-abelian Yang-Mills analysis of the string current, the string charge density is computed and is shown to have support in the region between the D-brane world-volumes. The 't Hooft-Polyakov monopole is analyzed using similar methods, and is shown to contain D-strings whose flux has support off the D-brane world-volume defined by the Higgs scalar field, when this field is interpreted in terms of a transverse dimension. The constructions presented here are used to give a qualitative picture of tachyon condensation in the Yang-Mills limit, where fundamental strings and lower-dimensional D-branes arise in a volume of space-time where brane-antibrane annihilation has occurred.