Title of article
Characters of countably tight spaces and inaccessible cardinals
Author/Authors
Usuba، نويسنده , , Toshimichi، نويسنده ,
Issue Information
دوماهنامه با شماره پیاپی سال 2014
Pages
12
From page
95
To page
106
Abstract
In this paper, we study some connections between characters of countably tight spaces of size ω 1 and inaccessible cardinals. A countable tight space is indestructible if every σ-closed forcing notion preserves countable tightness of the space. We show that, assuming the existence of an inaccessible cardinal, the following statements are consistent:(1)
indestructibly countably tight space of size ω 1 has character ⩽ ω 1 .
> ω 2 and there is no countably tight space of size ω 1 and character ω 2 .
he converse, we show that, if ω 2 is not inaccessible in the constructible universe L, then there is an indestructibly countably tight space of size ω 1 and character ω 2 .
Keywords
Countable tight space , Countable tightness indestructibility , Topological game , Kurepa tree , Inaccessible cardinal
Journal title
Topology and its Applications
Serial Year
2014
Journal title
Topology and its Applications
Record number
1584010
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