Timeline for Negative sectional curvature and constant curvature
Current License: CC BY-SA 3.0
9 events
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| Aug 30, 2021 at 14:05 | history | made wiki | Post Made Community Wiki by Stefan Kohl♦ | ||
| Sep 10, 2017 at 2:24 | history | edited | Misha | CC BY-SA 3.0 |
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| Jun 11, 2013 at 16:31 | comment | added | Igor Belegradek | By "random groups with expanders" I meant the groups constructed by adding relations to a free group randomly according to edges of a expander. Sloppy language... | |
| Jun 11, 2013 at 16:13 | history | edited | Misha | CC BY-SA 3.0 |
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| Jun 11, 2013 at 16:13 | comment | added | Misha | @Igor: A hyperbolic group can never contain an expander. On the other hand, you are right, I somehow forgot about Gromov's examples. I will modify my answer. | |
| Jun 11, 2013 at 15:54 | comment | added | Igor Belegradek | In fact, these hyperbolic groups aren't fundamental groups of complete nonpositivaly curved (Riemannian) manifolds. | |
| Jun 11, 2013 at 15:52 | comment | added | Igor Belegradek | Misha, there are torsion-free hyperbolic groups that aren't the fundamental group of a manifold in Class 1. Namely, Gromov's random groups with expanders, see Naor-Silberman's theorem 1.1 in arxiv.org/abs/1005.4084. | |
| Jun 8, 2013 at 5:25 | history | edited | Misha | CC BY-SA 3.0 |
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| Jun 8, 2013 at 5:17 | history | answered | Misha | CC BY-SA 3.0 |