Cox rings of rational surfaces and redundant blow-ups
arXiv:1303.2274
Abstract
We prove that the redundant blow-up preserves the finite generation of the Cox ring of a rational surface under a suitable assumption, and we study the birational structure of Mori dream rational surfaces via redundant blow-ups. It turns out that the redundant blow-up completely characterizes birational morphisms of Mori dream rational surfaces with anticanonical Iitaka dimension . As an application, we construct new Mori dream rational surfaces with anticanonical Iitaka dimension and of arbitrarily large Picard number.
16 pages. We have divided it into two parts and changed the title. This part will appear in Trans. Amer. Math. Soc