Living Inside a Hedgehog: Higher-dimensional Solutions that Localize Gravity

We consider spherically symmetric higher-dimensional solutions of Einstein’s equations with a bulk cosmological constant and n transverse dimensions. In contrast to the case of one or two extra dimensions we find no solutions that localize gravity when $n\ge 3$, for strictly local topological defects. We discuss global topological defects that lead to the localization of gravity and estimate the corrections to Newton’s law. We show that the introduction of a bulk ``hedgehog’’ magnetic field leads to a regular geometry and localizes gravity on the 3-brane with either a positive, zero or negative bulk cosmological constant. The corrections to Newton’s law on the 3-brane are parametrically the same as for the case of one transverse dimension.