Supersymmetric chiral normal coordinates

The (anti-) chiral Killing vectors of the supersymmetric Kaehler manifold associated with the nonlinear realization of a global symmetry are used to define (anti-) chiral normal coordinates. This in turn leads to a background superfield expansion of the super-Kaehler potential that is manifestly gauge invariant and supersymmetric. The chiral normal coordinates are further employed to construct a background superfield expansion for a locally gauge invariant supersymmetric action. (orig.)