Defect Branes

TL;DR

This paper classifies supersymmetric defect branes of co-dimension two in string theory, explores their higher-dimensional origins, and reveals their relation to mixed-symmetry tensors and supersymmetry algebra central charges.

Contribution

It provides a comprehensive classification of supersymmetric defect branes in various dimensions and links them to higher-dimensional branes, monopoles, and dual tensor structures.

Findings

Complete classification of supersymmetric defect branes in 2 < D < 11.

Identification of their origin as branes and monopoles in string/M-theory.

Discovery of the relation between defect branes and mixed-symmetry tensors.

Abstract

We discuss some general properties of "defect branes", i.e. branes of co-dimension two, in (toroidally compactified) IIA/IIB string theory. In particular, we give a full classification of the supersymmetric defect branes in dimensions 2 < D < 11 as well as their higher-dimensionalstring and M-theory origin as branes and a set of "generalized" Kaluza-Klein monopoles. We point out a relation between the generalized Kaluza-Klein monopole solutions and a particular type of mixed-symmetry tensors. These mixed-symmetry tensors can be defined at the linearized level as duals of the supergravity potentials that describe propagating degrees of freedom. It is noted that the number of supersymmetric defect branes is always twice the number of corresponding central charges in the supersymmetry algebra.