At the horizon of a supersymmetric AdS5 black hole:: Isometries and half-BPS giants

The near-horizon geometry of an asymptotically AdS5 supersymmetric black hole discovered by Gutowski and Reall is analysed. After lifting the solution to 10 dimensions, we explicitly solve the Killing spinor equations in both AdS2 Poincare and global coordinates. It is found that exactly four supersymmetries are preserved which is twice the number for the full black hole. The full set of isometries is constructed and the isometry supergroup is shown to be SU(1, 1 vertical bar 1) x SU(2) x U(3). We further study half-BPS configurations of D3-branes in the near- horizon geometry in Poincare and global coordinates. Both giant graviton probes and dual giant graviton probes are found.