NS Fivebrane and Tachyon Condensation
arXiv:hep-th/0312245 · doi:10.1063/1.1922069
Abstract
We argue that a semi-infinite D6-brane ending on an NS5-brane can be obtained from the condensation of the tachyon on the unstable D9-brane of type IIA theory. The construction uses a combination of the descriptions of these branes as solitons of the worldvolume theory of the D9-brane. The NS5-brane, in particular, involves a gauge bundle which is operator valued, and hence is better thought of as a gerbe.
20 pages, harvmac