Counting Supertubes

TL;DR

This paper quantizes supertubes using the Born-Infeld action, deriving an entropy formula that supports their role as generic D0-F1 bound states and reveals their marginal stability.

Contribution

It provides a direct quantization method for supertubes and confirms their entropy matches theoretical predictions, establishing them as generic bound states.

Findings

Derived entropy formula for supertubes

Confirmed supertubes as marginal bound states

Linked supertubes to three-charge black hole models

Abstract

The quantum states of the supertube are counted by directly quantizing the linearized Born-Infeld action near the round tube. The result is an entropy $S = 2\pi \sqrt{2 (Q_{D0}Q_{F1}-J)}$, in accord with conjectures in the literature. As a result, supertubes may be the generic D0-F1 bound state. Our approach also shows directly that supertubes are marginal bound states with a discrete spectrum. We also discuss the relation to recent suggestions of Mathur et al involving three-charge black holes.