Brane Dynamics From the Born-Infeld Action

TL;DR

This paper investigates D-brane dynamics using the Born-Infeld action, revealing BPS solutions representing fundamental strings and D-branes, and analyzing their properties and boundary conditions.

Contribution

It demonstrates that classical gauge configurations in the Born-Infeld framework can be BPS-saturated and correspond to fundamental strings and D-branes, providing new insights into brane structure.

Findings

Point charge solutions represent fundamental strings attached to branes.

Vortex solutions correspond to D1-branes attached to D3-branes.

S-matrix analysis aligns with open string boundary conditions.

Abstract

We use the abelian Born-Infeld action for the worldvolume gauge field and transverse displacement scalars to explore new aspects of D-brane structure and dynamics. We study several classic gauge field configurations, including point charges in any worldvolume dimension and vortices in two worldvolume dimensions, and show that, with an appropriate excitation of the transverse coordinate field, they are BPS-saturated solutions. The Coulomb point charge solutions turn out to represent, with considerable fidelity, fundamental strings attached to the brane (their magnetic counterparts describe D1-branes attached to D3-branes). We also show that S-matrix for small excitations propagating on the point charge solution is consistent with (and gives further illuminating information about) Polchinski's effective open string boundary condition.