Uniqueness of birational structures on Inoue surfaces

Abstract

We prove that the natural $(\operatorname{Aff} _2(\mathbf{C}),\mathbf{C}^2)$-structure on an Inoue surface is the unique $(\operatorname{Bir}(\mathbb{P}^2),\mathbb{P}^2(\mathbf{C}))$-structure, generalizing a result of Bruno Klingler which asserts that the natural $(\operatorname{Aff}_2(\mathbf{C}),\mathbf{C}^2)$-structure is the unique $(\operatorname{PGL} _3(\mathbf{C}),\mathbb{P}^2(\mathbf{C}))$-structure.