Gravitational Duality, Branes and Charges

TL;DR

This paper explores the duality and charge structures of D-branes and 9-branes in string and M-theory, revealing new charge types, their role in supersymmetry, and implications for string theory classifications.

Contribution

It introduces a dual D-5 brane charge K, relates it to NUT charge, and discusses its role in superalgebra, BPS bounds, and string theory dualities, including orientifolds and higher-dimensional origins.

Findings

K charge relates to NUT charge and appears in superalgebra.

Kaluza-Klein monopoles carry the K charge, identified as D-5 branes.

Different orientifold constructions yield type I and heterotic strings.

Abstract

It is argued that D=10 type II strings and M-theory in D=11 have D-5 branes and 9-branes that are not standard p-branes coupled to anti-symmetric tensors. The global charges in a D-dimensional theory of gravity consist of a momentum $P_M$ and a dual D-5 form charge $K_{M_1...M_{D-5}}$, which is related to the NUT charge. On dimensional reduction, P gives the electric charge and K the magnetic charge of the graviphoton. The charge K is constructed and shown to occur in the superalgebra and BPS bounds in $D\ge 5$, and leads to a NUT-charge modification of the BPS bound in D=4. $K$ is carried by Kaluza-Klein monopoles, which can be regarded as D-5 branes. Supersymmetry and U-duality imply that the type IIB theory has (p,q) 9-branes. Orientifolding with 32 (0,1) 9-branes gives the type I string, while modding out by a related discrete symmetry with 32 (1,0) 9-branes gives the SO(32) heterotic string. Symmetry enhancement, the effective world-volume theories and the possibility of a twelve dimensional origin are discussed.