Kaluza-Klein Branes

Abstract

We examine Kaluza-Klein branes in detail. Specifically, we show that codimension four submanifolds that are stationary under a semi-free circle action may be interpreted as branes or antibranes in the Kaluza-Klein reduced space that are magnetically charged under the Kaluza-Klein field strength. We derive the equation in cohomology that is satisfied by such a brane using an explicit construction of the Thom class of the normal bundle of the brane worldvolume in the reduced space. This may be applied to both the D6-brane of Type IIA String Theory, and also to various recent constructions of magnetic branes immersed in fluxbrane backgrounds. We then go on to study the special case of monopole-antimonopole production in a five-dimensional Kaluza-Klein theory, illustrating our arguments with various concrete examples.