Skip to main content
3 events
when toggle format what by license comment
Aug 29, 2012 at 20:41 comment added Ryan Budney Hi Igor, yes it really depends on what level of generality the question is asked in. Say $M$ is compact, and $N$ is compact without boundary -- so we will head for the conclusion that $M$ is a disc bundle over $N$. This side-steps the issue of ends and puts you into pre-Siebenmann mathematics. The idea is $N$ is embedded in $M$ (as you mention) so the complement of an open tubular neighbourhood of $N$ is $M$ becomes an h or s-cobordism depending on your assumptions, so it's a product.
Aug 29, 2012 at 18:13 comment added Igor Belegradek Regarding Step 1: how does being the homotopy type of $N$ forces anything? Don't you need some assumptions like those in my answer?
Aug 29, 2012 at 17:29 history answered Ryan Budney CC BY-SA 3.0