New unlikely intersections on elliptic surfaces

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Authors: Douglas L. Ulmer, José Felipe Voloch
Cited by: 0

Abstract

Consider a Jacobian elliptic surface $E \to C$ with a section $P$ of infinite order. Previous work of the first author and Urzúa over the complex numbers gives a bound on the number of tangencies between $P$ and a torsion section of $E$ (an ``unlikely intersection''), and more precisely, an exact formula for the weighted number of tangencies between $P$ and elements of the ``Betti foliation''. This work used analytic techniques that apparently do not generalize to positive characteristic. In this paper, we extend their work to characteristic $p$, and we develop a second approach to tangency properties of algebraic curves on a complex elliptic surface, yielding a new family of unlikely intersections with a strong connection to a famous homomorphism of Manin. We also correct inaccuracies in the literature about this homomorphism.

Fields of Study & Subjects

Algebraic Geometry and Number Theory Advanced Differential Equations and Dynamical Systems Polynomial and algebraic computation

Publication details

Journal / source
Proceedings of the American Mathematical Society
Publication date
10 September 2026
Language
EN