English

Pervasive ellipticity in locally compact groups

Group Theory 2025-06-12 v1 General Topology Representation Theory

Abstract

A topological group is (openly) almost-elliptic if it contains a(n open) dense subset of elements generating relatively-compact cyclic subgroups. We classify the (openly) almost-elliptic connected locally compact groups as precisely those with compact maximal semisimple quotient and whose maximal compact subgroups act trivial-weight-freely on the Euclidean quotients of the closed derived series' successive layers. In particular, an extension of a compact connected group K\mathbb{K} by a connected, simply-connected solvable Lie group L\mathbb{L} is (openly) almost-elliptic precisely when the weights of the K\mathbb{K}-action on Lie(L)Lie(\mathbb{L}) afforded by the extension are all non-trivial.

Keywords

Cite

@article{arxiv.2506.09642,
  title  = {Pervasive ellipticity in locally compact groups},
  author = {Alexandru Chirvasitu},
  journal= {arXiv preprint arXiv:2506.09642},
  year   = {2025}
}

Comments

17 pages + references

R2 v1 2026-07-01T03:11:03.614Z