Spectral flow and boundary string field theory for angled D-branes

TL;DR

This paper explores the dynamics of angled D-branes using spectral flow and boundary string field theory, providing a detailed tachyon potential that models brane recombination and decay processes.

Contribution

It introduces a novel approach using worldsheet twist superfields and spectral flow to analyze D-brane interactions at arbitrary angles, extending the understanding of tachyon condensation.

Findings

Derived the complete tachyon potential as a function of brane angle

Interpolated between brane-antibrane and Dirac-Born-Infeld actions

Provided insights into D-brane recombination mechanisms

Abstract

D-branes intersecting at an arbitrary fixed angle generically constitute a configuration unstable toward recombination. The reconnection of the branes nucleates at the intersection point and involves a generalization of the process of brane decay of interest to non-perturbative string dynamics as well as cosmology. After reviewing the string spectrum of systems of angled branes, we show that worldsheet twist superfields may be used in the context of Boundary Superstring Field Theory to describe the dynamics. Changing the angle between the branes is seen from the worldsheet as spectral flow with boundary insertions flowing from bosonic to fermionic operators. We calculate the complete tachyon potential and the low energy effective action as a function of angle and find an expression that interpolates between the brane-antibrane and the Dirac-Born-Infeld actions. The potential captures the mechanism of D-brane recombination and provides for interesting new physics for tachyon decay.