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 classifying-spaces
Search options not deleted
user 32022
The classifying space BG of a group G classifies principal G-bundles, in that homotopy classes of maps [X, BG] are naturally identified with isomorphism classes of principal G-bundles P ⭢ X.
11
votes
Accepted
Characteristic classes of non-linear sphere bundles
For many values of $n$, the answer to both questions is no. Since the fundamental groups of $BX$ and $B\mathrm{Diff}(S^n)$ are finite for $n\ge5$ (This uses that $\pi_0\mathrm{Diff}_\partial(D^n)$ is …
- 2,974
6
votes
Accepted
Classifying spaces of topological groups whose underlying spaces are homotopy equivalent
As John Klein remarked, the answer to this question will depend on the classifying space functor $B$ one uses.
Let me present one case for which the question can be answered positive which is basical …
- 2,974
8
votes
cohomology of BG, G compact Lie group
Just for completeness, here's another argument without spectral sequences via rational homotopy theory.
Recall a theorem of Hopf, which states that the rational cohomology of a path-connected H-space …
- 2,974