Biaa lynicki-Birula: Finiteness of the number of maximal open subsets with good quotients
- Biaa lynicki-Birula: Finiteness of the number of…
A toric prevariety is a normal complex prevariety endowed with an eeective regular torus action that has a dense orbit. We introduce the concept of a system of fans in a lattice and obtain an equivalence of the category of systems of fans and the category of toric prevarieties. For every toric prevariety X we construct a toric morphism X ! Y to a toric variety Y that is universal with respect to toric morphisms from X to toric varieties.