English

Algebraicity criteria, invariant subvarities and transcendence problems from arithmetic dynamics

Number Theory 2022-02-21 v1 Algebraic Geometry Dynamical Systems

Abstract

We introduce an algebraicity criteria. It has the following form: under certain conditions, an analytic subvariety of some algebriac variety over a global field KK, if it contains many KK-points, then it is algebraic over K.K. This gives a way to show the transcendence of points via the transcendence of analytic subvarieties. Such a situation often appears when we have a dynamical system, because we can often produce infinitely many points from one point via iterates. Combing this criteria and the study of invariant subvarieties, we get some results on the transcendence in arithmetic dynamics. We get a characterization of products of B\"ottcher coordinates or products of multiplicative canonical heights for polynomial dynamical pairs to be algebraic. For this, we studied the invariant subvarieties for product of endomorphisms. In particular, we partially generate Medvedev-Scanlon's classification of invariant subvarieties of split polynomial maps to separable endomorphisms on (P1)N(\mathbb{P}^1)^N in any characteristic. We also get some hight dimensional partial generalization via introducing of a notion of independence. We then study dominant endomorphisms ff on AN\mathbb{A}^N over a number field of algebraic degree d2d\geq 2. We show that in most of the cases (e.g. when such an endomorphism extends to an endomorphism on PN\mathbb{P}^N), there are many analytic curves centered at infinity which are periodic. We show that for most of them, it is algebraic if and only if it contains one algebraic point. We also study the periodic curves. We show that for most of ff, all periodic curves has degree at most 22. When N=2N=2, we get a more precise classification result. We show that under a condition which is satisfied for a general ff, if ff has infinitely many periodic curves, then ff is homogenous up to a changing of origin.

Keywords

Cite

@article{arxiv.2202.09032,
  title  = {Algebraicity criteria, invariant subvarities and transcendence problems from arithmetic dynamics},
  author = {Junyi Xie},
  journal= {arXiv preprint arXiv:2202.09032},
  year   = {2022}
}

Comments

50 pages

R2 v1 2026-06-24T09:43:51.272Z