  The geometry that is defined by the scalars in couplings of Einstein-Maxwell
theories in N=2 supergravity in 4 dimensions is denoted as special Kaehler
geometry. There are several equivalent definitions, the most elegant ones
involve the symplectic duality group. The original construction used conformal
symmetry, which immediately clarifies the symplectic structure and provides a
way to make connections to quaternionic geometry and Sasakian manifolds.
