English

Algebraic points of small height missing a union of varieties

Number Theory 2010-06-08 v2

Abstract

Let KK be a number field, Q\overline{\mathbb Q}, or the field of rational functions on a smooth projective curve over a perfect field, and let VV be a subspace of KNK^N, N2N \geq 2. Let ZKZ_K be a union of varieties defined over KK such that VZKV \nsubseteq Z_K. We prove the existence of a point of small height in VZKV \setminus Z_K, providing an explicit upper bound on the height of such a point in terms of the height of VV and the degree of a hypersurface containing ZKZ_K, where dependence on both is optimal. This generalizes and improves upon the previous results of the author. As a part of our argument, we provide a basic extension of the function field version of Siegel's lemma of J. Thunder to an inequality with inhomogeneous heights. As a corollary of the method, we derive an explicit lower bound for the number of algebraic integers of bounded height in a fixed number field.

Keywords

Cite

@article{arxiv.0808.2476,
  title  = {Algebraic points of small height missing a union of varieties},
  author = {Lenny Fukshansky},
  journal= {arXiv preprint arXiv:0808.2476},
  year   = {2010}
}

Comments

20 pages; revised and improved version -- in particular, the main result now stands over function fields of any genus; to appear in the Journal of Number Theory -- an earlier version also appeared in the MPIM preprint series

R2 v1 2026-06-21T11:11:38.193Z