Talk:Hedgehog space

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This article makes it seem like the $K$-Hedgehog space is the quotient space resulting from talking $K$ disjoint copies of $[0,1]$ and gluing them at $0$. For infinite $K$ however one such space in not first countable, and in particular not metrizable. I think this should be made clear. Maybe something like "take $K$ disjoing copies of $(0,1]$ and then a point $0^*$ and consider the following metric...". Or making it explicit that the hedgehog topology is strictly coarser that the quotient one given by gluing all the origins, and noting that the later one is not first countable. — Preceding unsigned comment added by (talk) 10:13, 14 July 2017 (UTC)

Brief edits[edit]

I deleted the statement about the Hedgehog space being a Moore space (true but unhelpful, because a Moore space is a generalization of a metric space, and the hedgehog space is a metric space) and the statement that the Hedgehog space satisfies "strong compactness properties" -- it is easy to see that it is not compact if the spininess is infinite.

I also added a reference to a one-page proof of Kowalsky's theorem. Plclark (talk) 06:17, 7 October 2008 (UTC)


Hi. See also wikibooks article . --Adam majewski (talk) 20:32, 21 December 2016 (UTC)