Title of article :
Normality and countable paracompactness of hyperspaces of ordinals
Author/Authors :
Kemoto، نويسنده , , Nobuyuki، نويسنده ,
Issue Information :
دوماهنامه با شماره پیاپی سال 2007
Abstract :
For an ordinal α, 2 α denotes the collection of all nonempty closed sets of α with the Vietoris topology and K ( α ) denotes the collection of all nonempty compact sets of α with the subspace topology of 2 α . It is well known that 2 α is normal iff cf α = 1 . In this paper, we will prove that for every nonzero-ordinal α:(1)
s countably paracompact iff cf α ≠ ω .
) is countably paracompact.
) is normal iff, if cfα is uncountable, then cf α = α .
), we use elementary submodel techniques.
Keywords :
Hyperspace , Ordinal , Elementary submodel , Countably paracompact , normal
Journal title :
Topology and its Applications
Journal title :
Topology and its Applications