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paracompact topological space (Definition)

A topological space $ X$ is said to be paracompact if every open cover of $ X$ has a locally finite open refinement.

In more detail, if $ (U_i)_{i\in I}$ is any family of open subsets of $ X$ such that

$\displaystyle \cup_{i\in I}U_i = X\;,$
then there exists another family $ (V_i)_{i\in I}$ of open sets such that
$\displaystyle \cup_{i\in I}V_i = X$
$\displaystyle V_i\subset U_i$ for all $\displaystyle i\in I$
and any specific $ x\in X$ is in $ V_i$ for only finitely many $ i$.

Some properties:



"paracompact topological space" is owned by mathcam. [ full author list (3) | owner history (3) ]
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Other names:  paracompact space
Also defines:  paracompact, paracompactness

Attachments:
strongly paracompact space (Definition) by yark
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Cross-references: pseudometric space, compact, regular, Hausdorff space, cover, partition of unity, metrizable space, metric, properties, open subsets, open refinement, locally finite, open cover, topological space
There are 13 references to this entry.

This is version 5 of paracompact topological space, born on 2002-01-22, modified 2007-06-24.
Object id is 1540, canonical name is Paracompact.
Accessed 7008 times total.

Classification:
AMS MSC54-00 (General topology :: General reference works )
 55-00 (Algebraic topology :: General reference works )

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