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1:38 AM
For instructions how to render MathJax(TeX) in chat see this post on meta or go directly to robjohn's website.
 
 
5 hours later…
6:16 AM
in Mathematics, 49 mins ago, by Daminark
Okay so Moore spaces may not be easy to construct in general
Although I'd guess that they are talking about the concept from algebraic topology - not general topolgoy.
In algebraic topology, a branch of mathematics, Moore space is the name given to a particular type of topological space that is the homology analogue of the Eilenberg–Maclane spaces of homotopy theory, in the sense that it has only one nonzero homology (rather than homotopy) group. == Formal definition == Given an abelian group G and an integer n ≥ 1, let X be a CW complex such that H n ( X ) ≅ G {\displaystyle H_{n}(X)\cong G} and ...
In mathematics, more specifically point-set topology, a Moore space is a developable regular Hausdorff space. Equivalently, a topological space X is a Moore space if the following conditions hold: Any two distinct points can be separated by neighbourhoods, and any closed set and any point in its complement can be separated by neighbourhoods. (X is a regular Hausdorff space.) There is a countable collection of open covers of X, such that for any closed set C and any point p in its complement there exists a cover in the collection such that every neighbourhood of p in the cover is disjoint from C...
 

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