Search Results
| Search type | Search syntax |
|---|---|
| Tags | [tag] |
| Exact | "words here" |
| Author |
user:1234 user:me (yours) |
| Score |
score:3 (3+) score:0 (none) |
| Answers |
answers:3 (3+) answers:0 (none) isaccepted:yes hasaccepted:no inquestion:1234 |
| Views | views:250 |
| Code | code:"if (foo != bar)" |
| Sections |
title:apples body:"apples oranges" |
| URL | url:"*.example.com" |
| Saves | in:saves |
| Status |
closed:yes duplicate:no migrated:no wiki:no |
| Types |
is:question is:answer |
| Exclude |
-[tag] -apples |
| For more details on advanced search visit our help page | |
Results tagged with homotopy-theory
Search options questions only
not deleted
user 41291
Homotopy theory is an important sub-field of algebraic topology. It is mainly concerned with the properties and structures of spaces which are invariant under homotopy. Chief among these are the homotopy groups of spaces, specifically those of spheres. Homotopy theory includes a broad set of ideas and techniques, such as cohomology theories, spectra and stable homotopy theory, model categories, spectral sequences, and classifying spaces.
4
votes
1
answer
224
views
A Dold-Thom style construction of a cohomology class from a sphere bundle
Re-reading my comment to the question https://mathoverflow.net/q/195912/41291 I suddenly realized that I do not understand something crucial about it. For the purposes of that crucial thing let me ref …
- 18.4k
5
votes
0
answers
232
views
Is this a stack?
A continuous map $f:X\to Y$ and a vector bundle $E\to X$ seem to give rise to a presheaf of groupoids on $Y$ along the following lines. For an open $U\subseteq Y$, each section of $f$ over $U$ (i. e. …
- 18.4k
5
votes
1
answer
308
views
Conceptual and practical reasons and consequences of inverting weak equivalences
Although dealing with this in one or other form for many years, to my shame this question only struck me now.
One of the most radical differences between categories of "algebraic" and "topological" ki …
- 18.4k
4
votes
0
answers
289
views
"Naïve"cobordism?
The naive view of (say, complex) cobordism of a space $X$ is that it should be the group generated by continuous families of closed manifolds parametrized by $X$. Acting even more naively, one may try …
- 18.4k
8
votes
1
answer
322
views
Is there an analog of compactified moduli spaces(/stacks) for smooth manifolds?
This question has been inspired by an answer to the question Reference request: Topology on the space of smooth compact submanifolds; I've asked it in a comment to that answer but then decided to make …
- 18.4k
8
votes
3
answers
646
views
Homotopy type of some lattices with top and bottom removed
The only reaction to this question on math.SE was 21 views in 4 days, so I decided to repost it here. I am not changing anything.
There was an interesting question on MO which OP removed by some reas …
- 18.4k
8
votes
2
answers
687
views
"Economic" Eilenberg-MacLane topological abelian groups
This might be regarded as a sequel to my previous "Economic" CW-structure for Eilenberg-MacLane spaces? However the content seems to be quite different.
I believe it is easy to prove that for any top …
- 18.4k
11
votes
3
answers
916
views
Can Homotopy Type Theory or algebraic geometry deal with homotopy fibers in terms of families?
((In conclusion)
It was hard to choose which answer to accept. I decided for the one which addressed most of the various aspects of the question.
)
(Later addon)
I now decided to put a bounty on t …
- 18.4k
11
votes
2
answers
551
views
The cofibration/fibration $\leftrightarrow$ epi/mono confusion
A recent question Why do we need model categories? reminded me of this long-standing confusion of mine -- I mentioned it in an answer there, and then decided to ask a separate question about it. I eve …
- 18.4k
9
votes
1
answer
228
views
Does the (1-)topos structure on simplicial sets have any homotopy-theoretic significance?
To give an example of a peculiar feature of simplicial sets that I cannot remember encountering anywhere in the context of homotopy theory: every simplicial set $X$ possesses partial map classifier $X …
- 18.4k
15
votes
2
answers
1k
views
"Economic" CW-structure for Eilenberg-MacLane spaces?
The only really "economic" cell structures for $K(\pi,n)$'s that I know is the one with a single cell in each dimension for $K(\mathbb Z/n\mathbb Z,1)$ and the one with a single cell in each even dime …
- 18.4k
22
votes
3
answers
2k
views
Stable homotopy type theory?
This is a combined question, strictly speaking I am asking three questions concerning, respectively, homotopy type theory, stable homotopy theory and Yetter-Drinfeld modules. But I believe in the pres …
- 18.4k
4
votes
0
answers
111
views
Is there a simple algebraic setup to accomodate fibres and cofibres at the same time?
If I understand it correctly, there are two mutually dual "leading principles" in homotopy theory:
never perform quotients, add structure instead;
never require subobjects, take fibres instead.
Al …
- 18.4k
3
votes
0
answers
247
views
Does the following first order approximation of the Kapranov-Vasserot infinitesimal loops st...
Let $X$ be a scheme over, say, a field $k$. Let us denote $\mathrm{Spec}(k[\varepsilon])$ by $T$ and its (unique) $k$-point by $0\in T$. Call the first order infinitesimal cone $C_{T,0}(X)$ over $X$ t …
- 18.4k
1
vote
1
answer
186
views
Comparing self-equivalences of a triangulated category and automorphisms of its Grothendieck...
There is a homomorphism from the group of (isomorphism classes of) self-equivalences of a triangulated category to the automorphism group of its Grothendieck group. Is this homomorphism surjective? If …
- 18.4k