Space-Time Supersymmetry, IIA/B Duality and M-Theory

TL;DR

This paper reexamines IIA/B string duality through N=2, D=9 supersymmetry, showing that BPS states transform as inequivalent supermultiplets, confirming the duality and linking M-theory, IIA, and IIB theories.

Contribution

It demonstrates that IIA/B duality requires BPS states to be in inequivalent supermultiplets, providing a nontrivial confirmation of the duality within a supersymmetric framework.

Findings

BPS states transform as inequivalent supermultiplets for any finite radius.

The duality is confirmed through supersymmetry considerations.

An SL(2,Z) invariant field theory unifies M-theory, IIA, and IIB states.

Abstract

The connection between IIA superstring theory compactified on a circle of radius R and IIB theory compactified on a circle of radius 1/R is reexamined from the perspective of N=2, D=9 space-time supersymmetry. We argue that the consistency of IIA/B duality requires the BPS states corresponding to momentum and winding of either of the type-II superstrings to transform as inequivalent supermultiplets. We show that this is indeed the case for any finite compactification radius, thus providing a nontrivial confirmation of IIA/B duality. From the point of view of N=2, D=9 supergravity, one is naturally led to an SL(2,Z) invariant field theory that encompasses both the M-theory torus and the Kaluza-Klein states of the IIB theory.