Vacuum-Defect Wormholes and a Mirror World

We have recently discovered a smooth vacuum-wormhole solution of the first-order equations of general relativity. Here, we obtain the corresponding multiple-vacuum-wormhole solution. Assuming that our world is essentially Minkowski spacetime with a large number of these vacuum-defect wormholes inserted, there is then another flat spacetime with opposite spatial orientation, which may be called a"mirror"world. We briefly discuss some phenomenological aspects and point out that there will be no significant vacuum-Cherenkov radiation in our world, so that ultrahigh-energy cosmic rays do not constrain the typical size and separation of the wormhole mouths (different from the constraints obtained for a single Minkowski spacetime with similar defects). Other signatures from a"gas"of vacuum-defect wormholes are mentioned, including a possible time machine.