Ax-Lindemann-Weierstrass with derivatives and the genus 0 Fuchsian groups

Abstract

We prove the Ax-Lindemann-Weierstrass theorem with derivatives for the uniformizing functions of genus zero Fuchsian groups of the first kind. Our proof relies on differential Galois theory, monodromy of linear differential equations, the study of algebraic and Liouvillian solutions, differential algebraic work of Nishioka towards the Painlev\'e irreducibility of certain Schwarzian equations, and considerable machinery from the model theory of differentially closed fields. Our techniques allow for certain generalizations of the Ax-Lindemann-Weierstrass theorem which have interesting consequences. In particular, we apply our results to answer a question of Painlev\'e (1895). We also answer certain cases of the Andr\'e-Pink conjecture, namely in the case of orbits of commensurators of Fuchsian groups.