A note on supersymmetric D-brane dynamics

TL;DR

This paper investigates how spin effects influence D-brane interactions in string theory, revealing that one-loop calculations capture these effects and relate to supergravity field exchanges.

Contribution

It demonstrates that boundary state insertions of supercharges reveal spin-dependent potentials and shows that massless annulus computations suffice to reproduce these effects.

Findings

Spin-dependent D-brane potentials are derived from supercharge insertions.

One-loop (M)atrix theory calculations encode all spin effects in low-energy interactions.

Massless annulus computations reproduce next-to-leading order spin effects.

Abstract

We study the spin dependence of D-brane dynamics in the Green-Schwarz formalism of boundary states. In particular we show how to interpret insertion of supercharges on the boundary state as sources of non-universal spin effects in D-brane potentials. In this way we find for a generic (D)p-brane, potentials going like $v^{4-n}/r^{7-p+n}$ corresponding to interactions between the different components of the D-brane supermultiplet. From the eleven dimensional point of view, these potentials arise from the exchange of field strengths corresponding to the graviton and the three form, coupled non-minimally to the branes. We show how an annulus computation truncated to its massless contribution is enough to reproduce these next-to-leading effects, meaning in particular that the one-loop (M)atrix theory effective action should encode all the spin dependence of low-energy supergravity interactions.