Entropy of Black Holes in N=2 Supergravity

Using the techniques of isolated horizon formalism, we construct the space of solutions of asymptotically flat extremal black holes in N=2 pure supergravity in 4 dimensions. We prove the laws of black hole mechanics. Further, restricting to constant area phase space, we show that the spherical horizons admits a U(1) Chern- Simons theory. Standard way of quantizing this topological theory and counting states confirms that entropy is indeed proportional to the area of horizon.