Timeline for On connectedness of intersection of subgroups
Current License: CC BY-SA 4.0
5 events
| when toggle format | what | by | license | comment | |
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| Jan 20, 2019 at 10:40 | answer | added | Friedrich Knop | timeline score: 4 | |
| Jan 19, 2019 at 21:10 | comment | added | LSpice | Also intersection with Levi subgroups of reductive groups often behaves well, as one shows using the fact they are centralisers of tori. | |
| Jan 19, 2019 at 21:09 | comment | added | LSpice | In general, I think you're out of luck. (However, perhaps one could handle the case where $U$ is the unipotent radical of a parabolic, and hence filtered by $\mathfrak{gl}_1$'s, and that such groups have no smooth, finite subgroups?) It may be of interest to know Proposition 14.22(a) of Borel, which states that the intersection of two parabolics is connected; that seems close to your situation. | |
| Jan 19, 2019 at 17:25 | review | First posts | |||
| Jan 19, 2019 at 20:46 | |||||
| Jan 19, 2019 at 17:25 | history | asked | Lifan Guan | CC BY-SA 4.0 |