English

Effective atypical intersections and applications to orbit closures

Algebraic Geometry 2025-07-18 v2 Dynamical Systems Number Theory

Abstract

We propose a unifying setting for dealing with monodromically atypical intersections that goes beyond the usual Zilber-Pink conjecture. In particular we obtain a new proof of finiteness of the maximal atypical orbit closures in each stratum of translation surfaces ΩMg(κ)\Omega \mathcal{M}_g (\kappa), as given by Eskin, Filip, and Wright. We also describe a concrete algorithm, implementable in principle on a computer, which provably computes all maximal orbit closures which are 'atypical' in a sense described by Filip. The same methods also give a general algorithm for computing atypical special loci associated to systems of differential equations, and in particular give an effective and o-minimal free proof of the geometric Zilber-Pink conjecture for variations of mixed Hodge structures.

Keywords

Cite

@article{arxiv.2406.16628,
  title  = {Effective atypical intersections and applications to orbit closures},
  author = {Gregorio Baldi and David Urbanik},
  journal= {arXiv preprint arXiv:2406.16628},
  year   = {2025}
}
R2 v1 2026-06-28T17:17:16.882Z