Extremal Charged Black Holes with a Twisted Extra Dimension

We construct odd-dimensional extremal charged black hole solutions with a twisted S^1 as an extra dimension on generalized Euclidean Taub-NUT spaces. There exists a null hypersurface where an expansion for an outgoing null geodesic congruence vanishes, then these spacetimes look like black holes. We show that the metrics admit C^0 extension across the horizon, but some components of Riemann curvature diverge there if the dimension is higher than five. The singularity is not much strong so that an observer along a free-fall geodesic can traverse the horizon. We also show solutions with a positive cosmological constant.Comment: 21 pages, no figure, v2 added reference

Coalescence of Rotating Black Holes on Eguchi-Hanson Space

We obtain new charged rotating multi-black hole solutions on the Eguchi-Hanson space in the five-dimensional Einstein-Maxwell system with a Chern-Simons term and a positive cosmological constant. In the two-black holes case, these solutions describe the coalescence of two rotating black holes with the spatial topologies of S^3 into a single rotating black hole with the spatial topology of the lens space S^3/Z_2. We discuss the differences in the horizon areas between our solutions and the two-centered Klemm-Sabra solutions which describe the coalescence of two rotating black holes with the spatial topologies of S^3 into a single rotating black hole with the spatial topology of S^3.Comment: 20 pages, 9 figure

Black Holes on Eguchi-Hanson Space in Five-Dimensional Einstein-Maxwell Theory

We construct a pair of black holes on the Eguchi-Hanson space as a solution in the five-dimensional Einstein-Maxwell theory.Comment: 4 pages, to be published as a Brief Report in Physical Review