English

Arithmetic properties of families of plane polynomial automorphisms

Dynamical Systems 2024-09-13 v2 Complex Variables Number Theory

Abstract

Given an algebraic family f ⁣:Λ×A2Λ×A2f\colon\Lambda\times \mathbb{A}^2 \to \Lambda\times \mathbb{A}^2 of plane polynomial automorphisms of H\'enon type parameterized by a quasi-projective curve, defined over a number field K,\mathbb{K}, we investigate certain arithmetic properties of periodic points contained in a family of subvarieties XΛ×A2ΛX \subset \Lambda \times \mathbb{A}^2 \twoheadrightarrow \Lambda. First, consider XX as a curve. We prove that the set of parameters tΛ(Q)t\in\Lambda(\overline{\mathbb{Q}}), such that XtX_t is periodic, has bounded height. This generalizes a result of Patrick Ingram. Moreover, if XX is non-periodic, then under some mild conditions -- such as when the family is dissipative -- we show that there are, in fact, only finitely many periodic parameters. This extends a result of Charles Favre and Romain Dujardin. Second, let XX be a family of curves. Assuming XX is non-degenerate, we establish a uniform bound on the number of periodic points in each curve XtX_t, tΛ(Q)t\in \Lambda(\overline{\mathbb{Q}}) and show that the set of these periodic points have bounded height in Λ×A2\Lambda\times \mathbb{A}^2 as well. We then examine in more detail the non-degeneracy property in the case of dissipative families of quadratic H\'enon maps.

Keywords

Cite

@article{arxiv.2407.15952,
  title  = {Arithmetic properties of families of plane polynomial automorphisms},
  author = {Yugang Zhang},
  journal= {arXiv preprint arXiv:2407.15952},
  year   = {2024}
}

Comments

Minor modifications. Added Theorems 1.3 and 1.5 about sets of bounded height