2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/61417We construct a model space $C(\gsp(\bR^{2n}))$ for the variety of Abelian simply transitive groups of affine transformations of type ${\rm Sp}(\bR^{2n})$. The model is stratified and its principal stratum is a Zariski-open subbundle of a natural vector bundle over the Grassmannian of Lagrangian subspaces in $\bR^{2n}$. \noindent Next we show that every flat special Kähler manifold may be constructed locally from a holomorphic function whose third derivatives satisfy some algebraic constraint. In particular global models for flat special Kähler manifolds with constant cubic form correspond to a subvariety of $C(\gsp(\bR^{2n}))$.corrected typos, updated referencesDifferential GeometryHigh Energy Physics - TheoryRings and Algebras22E25, 22E45, 53C26text