English

Avoiding algebraic integers of bounded house in orbits of rational functions over cyclotomic closures

Number Theory 2025-03-07 v2

Abstract

Let kk be a number field with cyclotomic closure kcyck^{\mathrm{cyc}}, and let hkcyc(x)h \in k^{\mathrm{cyc}}(x). For A1A \ge 1 a real number, we show that {αkcyc:h(α)Z has house at most A} \{ \alpha \in k^{\mathrm{cyc}} : h(\alpha) \in \overline{\mathbb Z} \text{ has house at most } A \} is finite for many hh. We also show that for many such hh the same result holds if h(α)h(\alpha) is replaced by orbits h(h(h(α)))h(h(\cdots h(\alpha))). This generalizes a result proved by Ostafe that concerns avoiding roots of unity, which is the case A=1A=1.

Keywords

Cite

@article{arxiv.1608.04146,
  title  = {Avoiding algebraic integers of bounded house in orbits of rational functions over cyclotomic closures},
  author = {Evan Chen},
  journal= {arXiv preprint arXiv:1608.04146},
  year   = {2025}
}

Comments

11 pages; updated to version as published by PAMS