Persistence of Induced Wormholes in Brane Worlds

Higher-dimensional black holes have long been considered within the context of brane worlds. Recently, it was shown that the brane-world ethos also permits the consideration of higher-dimensional wormholes. When such a wormhole, preexisting in the bulk, impinges upon our universe, taken to be a positive-tension 3-brane, it induces the creation in our universe of a wormhole of ordinary dimensionality. The throat of this wormhole might fully constrict, pinch off, and thus birth a baby universe. Alternatively, the induced wormhole might persist. I show that persistence is more likely and note that the persistent wormhole manifests as a particle-like object whose interaction with cosmic matter is purely gravitational. As such it may be considered a viable candidate for the sort of weakly interacting massive particle long believed to be the prime constituent of cold dark matter.