Talk:Embedding

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You have new messages (last change).

1. What do you think of removing the fist section, I never saw use of embedding for groups...? Maybe it is used I simply do not know...

2. Can anybody use TeX makeup for last section? I know nothing about comuters, so please help...

Tosha

It seems that if you are going to discuss the equivalence between injective immersion and embedding in the compact case, then the definition of embedding as an injective proper immersion in the general case could be useful. Also, perhaps you could make sure the reader knows that only M needs to be compact.--Orthografer 05:16, August 16, 2005 (UTC)

[edit] Proper embeddings

I fixed the definition of a proper embedding. Cthulhu.mythos 08:47, 2 June 2006 (UTC)

In my opinion this notion of properness (involving boundaries) does not make sense in the general topolgical case but only for (differetiable) manifolds. --Trigamma 20:00, 14 January 2007 (UTC)
There is a different (but -- in the case of manifolds -- related) notion of "proper" in general topology: A map is proper if the preimages of compact sets are compact. In this sense, an embedding f \colon X \to Y is proper iff f − 1(K) is compact whenever K \subset Y is compact.--Trigamma 20:00, 14 January 2007 (UTC)
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