English

Algebraic dynamics of skew-linear self-maps

Algebraic Geometry 2018-03-13 v1 Dynamical Systems

Abstract

Let XX be a variety defined over an algebraically closed field kk of characteristic 00, let NNN\in\mathbb{N}, let g:XXg:X\dashrightarrow X be a dominant rational self-map, and let A:ANANA:\mathbb{A}^N\to \mathbb{A}^N be a linear transformation defined over k(X)k(X), i.e., for a Zariski open dense subset UXU\subset X, we have that for xU(k)x\in U(k), the specialization A(x)A(x) is an NN-by-NN matrix with entries in kk. We let f:X×ANX×ANf:X\times\mathbb{A}^N\dashrightarrow X\times \mathbb{A}^N be the rational endomorphism given by (x,y)(g(x),A(x)y)(x,y)\mapsto (g(x), A(x)y). We prove that if the determinant of AA is nonzero and if there exists xX(k)x\in X(k) such that its orbit Og(x)\mathcal{O}_g(x) is Zariski dense in XX, then either there exists a point z(X×AN)(k)z\in (X\times \mathbb{A}^N)(k) such that its orbit Of(z)\mathcal{O}_f(z) is Zariski dense in X×ANX\times \mathbb{A}^N or there exists a nonconstant rational function ψk(X×AN)\psi\in k(X\times \mathbb{A}^N) such that ψf=ψ\psi\circ f=\psi. Our result provides additional evidence to a conjecture of Medvedev and Scanlon.

Keywords

Cite

@article{arxiv.1803.03931,
  title  = {Algebraic dynamics of skew-linear self-maps},
  author = {Dragos Ghioca and Junyi Xie},
  journal= {arXiv preprint arXiv:1803.03931},
  year   = {2018}
}

Comments

To appear in Proceedings of the AMS

R2 v1 2026-06-23T00:48:49.174Z