Skip to main content
13 events
when toggle format what by license comment
Mar 26, 2021 at 15:16 history edited archipelago
edited tags
Mar 26, 2021 at 14:08 answer added skupers timeline score: 10
May 28, 2014 at 3:58 answer added Tom Goodwillie timeline score: 13
May 27, 2014 at 22:58 history edited John Klein
edited tags
May 27, 2014 at 22:28 answer added John Klein timeline score: 7
May 27, 2014 at 14:32 comment added Igor Belegradek @MarkGrant: Yes, I know there is a rich literature when $N=\mathbb R^n$, yet I do not know what makes this case special (other than the fact that people find knots interesting). For example, is Dax's result known to fail below the metastable range?
May 27, 2014 at 14:27 comment added Igor Belegradek @RicardoAndrade: my base point is a homotopy equivalence (as I stressed above), so its connectivity is not an issue.
May 27, 2014 at 14:20 comment added Ricardo Andrade Dear @Igor Belegradek: If you meant the result stated at the top of the page numbered 305 in Dax's article, then I think you have left out one necessary condition: the connectivity of the map $M\to N$ which you take as the basepoint must be at least $2\dim M-\dim N +k+1$. Since you are taking arbitrary maps, you must then impose the condition $2\dim M-\dim N +k+1\leq 0$, i.e. $k\leq\dim N-2\dim M -1$, which is exactly the estimate I wrote in my previous comment. By the way, you will find precisely this connectivity estimate on the first page of the introduction of Dax's article.
May 27, 2014 at 13:26 comment added Mark Grant There is some literature on the rational homotopy of spaces of long knots (embeddings $\mathbb{R}^m$ to $\mathbb{R}^n$ fixed outside a compact set $C\subset \mathbb{R}^m$). In that case $M$ is not closed, of course, but at least $M\to N$ is a homotopy equivalence. I gather people are trying to extend these results to $\operatorname{Emb}(M,N)$. You might glean some information on the current (4 years ago) state-of-the-art by looking at the list of open problems on Ismar Volic's web page, palmer.wellesley.edu/~ivolic/pdf/Papers/…
May 27, 2014 at 11:43 history edited Igor Belegradek CC BY-SA 3.0
added 69 characters in body
May 27, 2014 at 11:43 comment added Igor Belegradek @RicardoAndrade: I added a link to Dax's paper. The result is mentioned on the second page of the introduction. There were earlier results, but Dax's is the best available, I think.
May 27, 2014 at 4:24 comment added Ricardo Andrade I think the map $\operatorname{Emb}(M,N) \to \operatorname{Map}(M,N)$ is actually just $(\dim N - 2 \dim M - 1)$-connected, which should follow from some parametrized version of approximation of continuous maps by embeddings. This most likely predates Dax. By the way, I think the first bound you give is for something else (which does appear to be due to Dax) related to Haefliger's refined theory: see theorem 1.2.1 and the following remark in the survey you link to.
May 26, 2014 at 2:45 history asked Igor Belegradek CC BY-SA 3.0