English

A height gap in $GL_d(\overline{\mathbb{Q}})$ and almost laws

Group Theory 2021-11-01 v1 Number Theory

Abstract

E. Breuillard showed that finite subsets FF of matrices in GLd(Q)GL_d(\overline{\mathbb{Q}}) generating non-virtually solvable groups have normalized height h^(F)ϵd\widehat{h}(F) \ge \epsilon_d, for some positive ϵd>0\epsilon_d >0. The normalized height h^(F)\widehat{h}(F) is a measure of the arithmetic size of FF and this result can be thought of as a non-abelian analog of Lehmer's Mahler measure problem. We give a new shorter proof of this result. Our key idea relies on the existence of particular word maps in compact Lie groups (known as almost laws) whose image lies close to the identity element.

Keywords

Cite

@article{arxiv.2110.15404,
  title  = {A height gap in $GL_d(\overline{\mathbb{Q}})$ and almost laws},
  author = {Lvzhou Chen and Sebastian Hurtado and Homin Lee},
  journal= {arXiv preprint arXiv:2110.15404},
  year   = {2021}
}
R2 v1 2026-06-24T07:16:45.896Z