Skip to main content
15 events
when toggle format what by license comment
Jan 12, 2021 at 16:21 answer added Phil Tosteson timeline score: 3
Jan 12, 2021 at 15:30 history edited Vivek Shende CC BY-SA 4.0
deleted 20 characters in body
Jan 12, 2021 at 15:06 history edited Vivek Shende CC BY-SA 4.0
added 182 characters in body
Jan 12, 2021 at 14:41 comment added Tyrone You still need to be more careful: let $X$ be any space and consider $X_+=X\sqcup\{+\}$ (basepoint is the disjoint point). Again $\Omega(X_+)=\Omega(+)=\ast$. In general the statement is false even for connected spaces without some further assumptions. Let $X$ be the Warsaw circle. Then $X$ is not contractible. However $\Omega X$ is, and moreover the section $X\rightarrow\mathcal{L}X$ is an inverse homotopy equivalence to the evaluation map. (Of course $X$ is not of CW type).
Jan 12, 2021 at 14:33 comment added Maxime Ramzi In that case I think Goodwillie calculus might be interesting, especially if your desired target ($\infty$-)category is stable (for instance chain complexes if you're working up to quasi-isomorphism) - then excisive functors are related to finite colimit-preserving functors.
Jan 12, 2021 at 14:10 history edited Vivek Shende CC BY-SA 4.0
added 38 characters in body
Jan 12, 2021 at 14:09 comment added Vivek Shende @Tyrone I meant weak equivalence. Also I meant “each connected component is contractible.” Now I edited it to clarify.
Jan 12, 2021 at 14:07 comment added Tyrone Firstly, by isomorphism, you mean homeomorphism, or do you have something else in mind? Secondly, if $X=S^0$ is a two-point discrete space, then $\Omega S^0=\ast$ and $S^0\rightarrow\mathcal{L}S^0$ is a homeomorphism.
Jan 12, 2021 at 9:35 comment added Vivek Shende @MaximeRamzi, that’s ok — for what I need, finite colimits are enough.
Jan 12, 2021 at 9:02 comment added Maxime Ramzi I think (but I might be completely wrong) that usually the calculus of functors is related to finite colimits rather than arbitrary colimits (see the definition of excisive or $n$-excisive for instance)
Jan 12, 2021 at 2:47 history edited Vivek Shende CC BY-SA 4.0
deleted 55 characters in body
Jan 12, 2021 at 2:37 history edited Vivek Shende CC BY-SA 4.0
edited body
Jan 12, 2021 at 2:30 history edited Vivek Shende CC BY-SA 4.0
deleted 10 characters in body
Jan 12, 2021 at 2:24 history edited Vivek Shende CC BY-SA 4.0
added 6 characters in body
Jan 12, 2021 at 2:16 history asked Vivek Shende CC BY-SA 4.0