Limits of the D-brane action

TL;DR

This paper reformulates the D-brane action in terms of a scale parameter, exploring two key limits that lead to a string parton picture and a topological model, providing new insights into D-brane dynamics.

Contribution

It introduces a reformulation of the D-brane action using a scale parameter and analyzes two fundamental limits, revealing new physical interpretations.

Findings

In the limit of large string coupling, a string parton picture emerges.

As the scale parameter approaches zero, a topological model is obtained.

The reformulation facilitates perturbative analysis of D-brane theories.

Abstract

For background geometries whose metric contain a scale $\gamma$ we reformulate the Born-Infeld D-brane action in terms of $\epsilon \equiv \gamma /(2\pi \alpha ')$. This may be taken as a starting point for various perturbative treatments of the theory. We study two limits that arise at zeroth order of such perturbations. In the first limit, that corresponds to the $g_s\to\infty$ with $\epsilon$ fix, we find a "string parton" picture, also in the presense of some background RR-fields. In the second limit, $\epsilon\to 0$, we find a topological model.