Timeline for List of Classifying Spaces and Covers
Current License: CC BY-SA 3.0
22 events
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| Nov 11, 2014 at 21:01 | comment | added | Dan Petersen | ...and even if you find the previous example too silly, allowing yourself to work with stacks does give you several natural examples, like $\mathrm{SL}(2,\mathbf Z)$ acting on the upper half plane. | |
| Nov 11, 2014 at 20:57 | comment | added | Dan Petersen | Here's a really dumb non-answer (dumb enough that I only make it a comment), but sometimes I find it useful to think along these lines. Namely, if you permit yourself to think about topological stacks instead of topological spaces, you can take $EG = \ast$ (a single point) and $BG = [\ast/G]$ ($G$ any group). This is the universal and minimal choice of classifying space. | |
| Sep 25, 2014 at 17:39 | comment | added | Chris Gerig | $\mathbb{H}P^\infty$ | |
| Sep 25, 2014 at 12:01 | comment | added | Ali Taghavi | @ChrisGerig What is $BS^{3}$? | |
| Apr 26, 2012 at 23:40 | history | edited | Chris Gerig |
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| Mar 6, 2012 at 12:15 | answer | added | Samuel Tinguely | timeline score: 8 | |
| Mar 6, 2012 at 9:34 | answer | added | Ulrich Pennig | timeline score: 2 | |
| Mar 6, 2012 at 8:17 | answer | added | Ryan Budney | timeline score: 4 | |
| Mar 6, 2012 at 4:46 | answer | added | Yan Zou | timeline score: 1 | |
| Jan 1, 2012 at 1:58 | history | edited | Chris Gerig |
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| Dec 31, 2011 at 20:45 | history | made wiki | Post Made Community Wiki by Chris Gerig | ||
| Dec 31, 2011 at 19:36 | comment | added | Steve D | Dave Benson and Steve Smith wrote a book on the clasifying spaces of the sporadic simple groups. | |
| Dec 31, 2011 at 19:13 | history | edited | Chris Gerig | CC BY-SA 3.0 |
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| Feb 23, 2011 at 21:00 | answer | added | Johannes Ebert | timeline score: 10 | |
| Feb 23, 2011 at 20:59 | history | edited | Qfwfq | CC BY-SA 2.5 |
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| Feb 23, 2011 at 20:56 | answer | added | Johannes Ebert | timeline score: 10 | |
| Feb 23, 2011 at 18:04 | history | edited | Chris Gerig | CC BY-SA 2.5 |
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| Feb 23, 2011 at 9:03 | comment | added | Somnath Basu | What do you mean by "associated cover"? For example, $\mathbb{CP}^\infty$ is already simply connected and perhaps the use of the word "cover" is a bit misleading. What you are looking for is the total space $EG$ associated to $G$. Towards that end, apart from Milnor's original construction it is worth looking at Segal's construction of $EG$ as well. It's very nice and in particular implies that $EG$ (in a suitable model) is an abelian group if $G$ is abelian! | |
| Feb 23, 2011 at 8:50 | answer | added | Neil Strickland | timeline score: 32 | |
| Feb 23, 2011 at 8:24 | answer | added | Dave Anderson | timeline score: 8 | |
| Feb 23, 2011 at 7:38 | answer | added | Craig Westerland | timeline score: 27 | |
| Feb 23, 2011 at 6:54 | history | asked | Chris Gerig | CC BY-SA 2.5 |