Article ID Journal Published Year Pages File Type
4658888 Topology and its Applications 2013 6 Pages PDF
Abstract

Let AA denote the Alexandroff–Urysohn double arrow space. We prove the following results: (a) A×2ω is not countable dense homogeneous; (b) Aω is not countable dense homogeneous; (c) AA has exactly cc types of countable dense subsets. These results answer questions by Arhangelʼskiĭ, Hrušák and van Mill.

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Physical Sciences and Engineering Mathematics Geometry and Topology
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