Appears in collection : Cox rings and applications / Anneaux de Cox et applications
The course starts with a reminder on toric varieties, which serve as an important and instructive example class for us. Then we switch to projective varieties with finitely generated divisor class group and study their Cox sheaf, Cox ring and the associated quotient presentation. We will focus in particular on the case of a finitely generated Cox ring. In this setting, we obtain natural embeddings into toric varieties, which in turn will lead to an explicit combinatorial approach to the geometry of the underlying variety. Specific examples, such as rational surfaces with $\mathbb{C^{²}}$-action, will be discussed in this context.