Timeline for Conditions for underlying space of an orbifold $\Bbb T^n/\Gamma$ to be a sphere?
Current License: CC BY-SA 3.0
12 events
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Apr 13, 2017 at 12:19 | history | edited | CommunityBot |
replaced http://math.stackexchange.com/ with https://math.stackexchange.com/
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Oct 14, 2015 at 0:14 | comment | added | Neil Hoffman | I think you could be overlooking one of the conditions of Dunbar when you say 'most' quotients of $T^3$ have underlying space $S^3$. In fact, there are several quotients of $T^3$ with underlying space $S^1\times S^2$, for example the product of the pillowcase $S^2(2,2,2,2)$ and $S^1$. These all turn out to be fibered orbifolds, so Dunbar doesn't focus on them. However, it should be pointed out that $S^2(2,2,2,2) \times S^1$ can cover itself, so 'most' perhaps might be 'most (up to homeomorphism)'. | |
Aug 14, 2015 at 22:32 | history | bounty ended | arivero | ||
Aug 13, 2015 at 16:52 | history | edited | Igor Rivin | CC BY-SA 3.0 |
added five dimensions
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Aug 12, 2015 at 17:21 | comment | added | arivero | well the underlying manifold must be a manifold, yep, but for the orbifold of course I am happy to allow for conical singularities and usual stuff (I just mention it for benefit of the casual passer-by) | |
Aug 12, 2015 at 16:34 | history | edited | Igor Rivin | CC BY-SA 3.0 |
added $n=4$ info.
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Aug 11, 2015 at 22:38 | history | edited | Igor Rivin | CC BY-SA 3.0 |
more examples
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Aug 8, 2015 at 23:46 | comment | added | arivero | Hmm having it for n=1,2,3 and possibly 4 starts to signal that dimension is not a main worry. It could have still some argument about having only conical singularities or more extended ones. | |
Aug 8, 2015 at 23:26 | history | edited | Igor Rivin | CC BY-SA 3.0 |
added 3-d thing.
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Aug 8, 2015 at 11:02 | history | edited | Igor Rivin | CC BY-SA 3.0 |
added projective space examples.
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Aug 8, 2015 at 10:17 | history | edited | Igor Rivin | CC BY-SA 3.0 |
made small correction, added example
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Aug 7, 2015 at 22:42 | history | answered | Igor Rivin | CC BY-SA 3.0 |