Countable Dense Homogeneity and the Double Arrow Space
arXiv:1809.06816
Abstract
Let denote the Alexandroff-Urysohn double arrow space. We prove the following results: (a) is not countable dense homogeneous; (b) is not countable dense homogeneous; (c) has exactly types of countable dense subsets. These results answer questions by Arhangel'ski\uı, Hrušák and van Mill.