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fully T4 (Definition)

A topological space $ X$ is said to be fully $ T_4$ if every open cover of $ X$ has star refinement.

A topological space is said to be fully normal if it is a $ T_1$ space and is fully $ T_4$.

For example, every pseudometric space is fully $ T_4$.

We have the following implications:

Lindelöf $ T_3 \Rightarrow$ paracompact and $ T_3 \Rightarrow$ fully $ T_4 \Rightarrow T_4 \Rightarrow$ uniformizable $ \Rightarrow T_3$ ,

and

fully normal $ \Leftrightarrow$ paracompact regular.



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Also defines:  fully normal
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Cross-references: regular, uniformizable, paracompact, Lindelöf, implications, pseudometric space, star refinement, open cover, topological space
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This is version 4 of fully T4, born on 2007-05-26, modified 2007-05-27.
Object id is 9473, canonical name is FullyT4.
Accessed 775 times total.

Classification:
AMS MSC54D15 (General topology :: Fairly general properties :: Higher separation axioms )

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