Dynamique analytique sur $\mathbf{Z}$. II : \'Ecart uniforme entre Latt\`es et conjecture de Bogomolov-Fu-Tschinkel

Abstract

We prove that the mutual energy (or the intersection product in the sense of Arakelov theory) of two dynamical systems associated to Latt\`es morphisms over $\mathbf{\bar Q}$ is uniformly bounded below and deduce a proof of a conjecture of Bogomolov-Fu-Tschinkel: the number of common images of torsion points of two non-isomorphic elliptic curves over $\mathbf{C}$ by a standard morphism to the projective line is uniformly bounded. The proof crucially relies on the theory of Berkovich spaces over $\mathbf{Z}$ and on an original argument allowing to obtain a global estimate from a central estimate (over a trivially valued field).