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 at.algebraic-topology
Search options not deleted
user 59302
Homotopy theory, homological algebra, algebraic treatments of manifolds.
21
votes
Rational homotopy groups of $S^2\vee S^2$
Piotr, I think the question you really want to ask is:
Given a map $f:S^n \to S^2 \vee S^2$, how do I prove that it is homotopically nontrivial?
This is the so-called homotopy period problem, and it …
- 934
14
votes
1
answer
1k
views
Whitehead products in homotopy groups of spheres
Here is what I know about Whitehead products in homotopy groups of spheres:
$[\mathrm{id}_{S^{2n}},\mathrm{id}_{S^{2n}}]$ has Hopf invariant (EDIT: $\pm$) two.
No element that survives into the stab …
- 52.6k
3
votes
A variant of $\ell^2$-cochains
I'm not sure if this should be a comment rather than an answer, since I'm not attempting to answer the hard questions (2) and (3). But it's too long to be a comment. That said:
First of all, I just …
- 934
7
votes
Accepted
A homeomorphism with a prescribed action on the fundamental group - decidable or not?
This is undecidable. For a construction, see the first page of Nabutovsky and Weinberger, "Algorithmic aspects of homeomorphism problems", Rothenberg Festschrift 1998.
- 934