GK-dimension of birationally commutative surfaces
GK-dimension of birationally commutative surfaces
Let $k$ be an algebraically closed field, let $K/k$ be a finitely generated field extension of transcendence degree $2$, let $\sigma \in \operatorname {Aut}_k(K)$, and let $A \subseteq Q = K[t; \sigma ]$ be an $\mathbb {N}$-graded subalgebra with $\dim _k A_n < \infty$ for all $n \geq 0$. Then …