A viable wormhole model in a five-dimensional spacetime

This paper generalizes two of the author's earlier wormhole solutions that are characterized by an extra spatial dimension. This paper adds the assumption that the components of the line element are functions not only of the radial coordinate $r$ but of the extra coordinate $l$ as well, resulting in a significant generalization. It is shown that the throat of the wormhole can be threaded with ordinary matter and that the unavoidable violation of the null energy condition can be attributed to the extra dimension. To be consistent with string theory, we also assume that this extra dimension has a small magnitude.