Flux Stabilization of D-branes

TL;DR

This paper demonstrates how quantized worldvolume fluxes stabilize D-branes on group manifolds, deriving their properties and matching them with conformal field theory predictions, while discussing charge quantization issues.

Contribution

It provides a detailed derivation of D-brane properties on SU(2) using Born-Infeld action and extends the analysis to other groups, confirming stability and spectrum predictions.

Findings

D-branes are stabilized by quantized fluxes.

Derived masses, multiplicities, and fluctuation spectra match CFT predictions.

Discussed non-quantization of RR charges.

Abstract

We explain how D-branes on group manifolds are stabilized against shrinking by quantized worldvolume U(1) fluxes. Starting from the Born-Infeld action in the case of the SU(2) group manifold we derive the masses, multiplicities and spectrum of small fluctuations of these branes, and show that they agree exactly with the predictions of conformal field theory, to all orders in the $\alpha^\prime$ expansion. We discuss the generalization to other groups and comment on an apparent paradox: why are the `RR charges' of these branes not quantized?