English

Manifolds counting and class field towers

Group Theory 2011-11-22 v2 Number Theory

Abstract

In [BGLM] and [GLNP] it was conjectured that if HH is a simple Lie group of real rank at least 2, then the number of conjugacy classes of (arithmetic) lattices in HH of covolume at most xx is x(γ(H)+o(1))logx/loglogxx^{(\gamma(H)+o(1))\log x/\log\log x} where γ(H)\gamma(H) is an explicit constant computable from the (absolute) root system of HH. In this paper we prove that this conjecture is false. In fact, we show that the growth is at rate xclogxx^{c\log x}. A crucial ingredient of the proof is the existence of towers of field extensions with bounded root discriminant which follows from the seminal work of Golod and Shafarevich on class field towers.

Keywords

Cite

@article{arxiv.0905.1841,
  title  = {Manifolds counting and class field towers},
  author = {Mikhail Belolipetsky and Alex Lubotzky},
  journal= {arXiv preprint arXiv:0905.1841},
  year   = {2011}
}

Comments

27 pages, a small change in title, final revision, to appear in Adv. Math

R2 v1 2026-06-21T13:01:11.029Z