Title of article :
A glance at spaces with closure-preserving local bases
Author/Authors :
Dow، نويسنده , , A. and Ramيrez Martيnez، نويسنده , , R. and Tkachuk، نويسنده , , V.V.، نويسنده ,
Issue Information :
دوماهنامه با شماره پیاپی سال 2010
Pages :
11
From page :
548
To page :
558
Abstract :
Call a space X (weakly) Japanese at a point x ∈ X if X has a closure-preserving local base (or quasi-base respectively) at the point x. The space X is (weakly) Japanese if it is (weakly) Japanese at every x ∈ X . We prove, in particular, that any generalized ordered space is Japanese and that the property of being (weakly) Japanese is preserved by σ-products; besides, a dyadic compact space is weakly Japanese if and only if it is metrizable. It turns out that every scattered Corson compact space is Japanese while there exist even Eberlein compact spaces which are not weakly Japanese. We show that a continuous image of a compact first countable space can fail to be weakly Japanese so the (weak) Japanese property is not preserved by perfect maps. Another interesting property of Japanese spaces is their tightness-monolithity, i.e., in every weakly Japanese space X we have t ( A ¯ ) ⩽ | A | for any set A ⊂ X .
Keywords :
Tightness , Japanese space , Compact space , ?-base , Discretely generated space , Closure-preserving family , First-countable space , Eberlein compact space , Weakly Japanese space
Journal title :
Topology and its Applications
Serial Year :
2010
Journal title :
Topology and its Applications
Record number :
1582399
Link To Document :
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