Tachyonic decay of unstable Dirichlet branes

TL;DR

This paper investigates the decay process of unstable bound states of supersymmetric Dirichlet branes through tachyonic condensation, revealing conditions under which decay occurs and analyzing the process via Hamiltonian and Lagrangian methods.

Contribution

It demonstrates that tachyonic decay of unstable Dirichlet branes occurs only when gauge fields are localized perpendicular to the tachyon direction, combining Hamiltonian and Lagrangian analysis.

Findings

Decay occurs via tachyonic condensation under specific gauge field localization.

Only gauge fields perpendicular to the tachyon direction enable decay.

The analysis combines Hamiltonian and Lagrangian approaches.

Abstract

We consider an unstable bound system of two supersymmetric Dirichlet branes of different dimensionality ($p,p'$ with $p'<p$) embedded in a flat non-compactified IIA or IIB type background. We study the decay, via tachyonic condensation, of such unstable bound states leading to a pair of bound D$(p-1)$, D$p'$-branes. We show that only when the gauge fields carried by the D$p$-brane are localised perependicular to the tachyon direction, then tachyon condensation will indeed take place. We perform our analysis by combining both, the Hamiltonian and the Lagrangian approach.