English

Haar meager sets, their hulls, and relationship to compact sets

General Topology 2016-04-01 v1

Abstract

Let GG be an abelian Polish group. We show that there is a strongly Haar meager set in GG without any FσF_{\sigma} Haar meager hull (and that this still remains true if we replace FσF_{\sigma} by any other class of the Borel hierarchy). We also prove that there is a coanalytic naively strongly Haar meager set without any Haar meager hull. Further, we investigate the relationship of the collection of all compact sets to the collection of all Haar meager sets in non-locally compact Polish groups.

Keywords

Cite

@article{arxiv.1603.09510,
  title  = {Haar meager sets, their hulls, and relationship to compact sets},
  author = {Martin Doležal and Václav Vlasák},
  journal= {arXiv preprint arXiv:1603.09510},
  year   = {2016}
}

Comments

18 pages

R2 v1 2026-06-22T13:22:11.161Z