Calabi-Yau Black Holes and Enhancement of Supersymmetry in Five Dimensions

BPS electric and magnetic black hole solutions which break half of supersymmetry in the theory of N=2 five-dimensional supergravity are discussed. For models which arise as compactifications of M-theory on a Calabi-Yau manifold, these solutions correspond, respectively, to the two and five branes wrapping around the homology cycles of the Calabi-Yau compact space. The electric solutions are reviewed and the magnetic solutions are constructed. The near-horizon physics of these solutions is examined and in particular the phenomenon of the enhancement of supersymmetry. The solutions for the supersymmetric Killing spinor of the near horizon geometry, identified as $Ad{S}_3\times S^2$ and $Ad{S}_2\times S^3$ are also given.