N=2 Super-Higgs, N=1 Poincare' Vacua and Quaternionic Geometry
  In the context of N=2 supergravity we explain the occurrence of partial super-Higgs with vanishing vacuum energy and moduli stabilization in a model suggested by superstring compactifications on type IIB orientifolds with 3-form fluxes.   The gauging of axion symmetries of the quaternionic manifold, together with the use of degenerate symplectic sections for special geometry, are the essential ingredients of the construction. 
L. Andrianopoli, R. D'Auria, S. Ferrara and M.A. Lledo'