Kaluza-Klein Black Holes with Squashed Horizons

We study geometrical structures of charged static black holes in the five-dimensional Einstein-Maxwell theory. The black holes we study have horizons in the form of squashed ${\mathrm{S}}^3$, and their asymptotic structure consists of a twisted ${\mathrm{S}}^1$ bundle over the four-dimensional flat spacetime at the spatial infinity. The spacetime we consider is fully five-dimensional in the vicinity of the black hole and four-dimensional with a compact extra dimension at infinity.