منابع مشابه
Countable dense homogeneity and λ - sets
We show that all sufficiently nice λ-sets are countable dense homogeneous (CDH). From this fact we conclude that for every uncountable cardinal κ ≤ b there is a countable dense homogeneous metric space of size κ. Moreover, the existence of a meager in itself countable dense homogeneous metric space of size κ is equivalent to the existence of a λ-set of size κ. On the other hand, it is consisten...
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We investigate which definable separable metric spaces are countable dense homogeneous (CDH). We prove that a Borel CDH space is completely metrizable and give a complete list of zero-dimensional Borel CDH spaces. We also show that for a Borel X ⊆ 2 the following are equivalent: (1) X is Gδ in 2 ω , (2) X is CDH and (3) X is homeomorphic to 2 or to ω . Assuming the Axiom of Projective Determina...
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ژورنال
عنوان ژورنال: Fundamenta Mathematicae
سال: 2014
ISSN: 0016-2736,1730-6329
DOI: 10.4064/fm226-2-5