Timeline for Betti numbers and lower central series quotients of finite-index subgroups of nilpotent groups
Current License: CC BY-SA 4.0
10 events
| when toggle format | what | by | license | comment | |
|---|---|---|---|---|---|
| Mar 1, 2021 at 1:30 | vote | accept | Irina | ||
| Feb 28, 2021 at 23:35 | answer | added | Andy Putman | timeline score: 6 | |
| Feb 27, 2021 at 20:28 | comment | added | Irina | (in particular, I don't think an answer to either one (positive or negative) directly implies an answer to the other) | |
| Feb 27, 2021 at 18:41 | comment | added | Irina | @YCor: Huh? I have no idea what you mean by "exact duplicate". This question is about the usual lower central series (as opposed to the torsion-free one), the other question has nothing to do with finite-index subgroups. I thought when posting about making this a 3-part question, but decided the other one was of a somewhat different flavor, so including it as part 3 of this question would make things too unfocused. | |
| Feb 27, 2021 at 13:16 | comment | added | YCor | Question 2 seems to be an exact duplicate of your other question mathoverflow.net/questions/385052, so I'd suggest to erase it. | |
| Feb 27, 2021 at 13:15 | comment | added | YCor | I think all this is true; there are indeed (2-step) nilpotent torsion-free nilpotent groups with non-torsion-free abelianization, but I don't think this is an issue. | |
| Feb 27, 2021 at 13:13 | history | edited | YCor | CC BY-SA 4.0 |
fixed confusing < which suggests proper subgroup; edited tags
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| Feb 27, 2021 at 6:48 | comment | added | Mark Grant | My recollection is that there are torsion-free f.g. nilpotent groups with torsion in their integral homology, among the finite index subgroups of the Heisenberg group. These may give counter examples to 1. | |
| Feb 27, 2021 at 2:09 | review | First posts | |||
| Feb 27, 2021 at 10:17 | |||||
| Feb 27, 2021 at 2:06 | history | asked | Irina | CC BY-SA 4.0 |