English

Countable Dense Homogeneity and the Double Arrow Space

General Topology 2018-09-19 v1

Abstract

Let A\mathbb{A} denote the Alexandroff-Urysohn double arrow space. We prove the following results: (a) A×ω2\mathbb{A}\times{}^\omega{2} is not countable dense homogeneous; (b) ωA{}^{\omega}{\mathbb{A}} is not countable dense homogeneous; (c) A\mathbb{A} has exactly c\mathfrak{c} types of countable dense subsets. These results answer questions by Arhangel'ski\u\i, Hru\v{s}\'ak and van Mill.

Cite

@article{arxiv.1809.06816,
  title  = {Countable Dense Homogeneity and the Double Arrow Space},
  author = {Rodrigo Hernández-Gutiérrez},
  journal= {arXiv preprint arXiv:1809.06816},
  year   = {2018}
}
R2 v1 2026-06-23T04:10:24.881Z