Timeline for Coxeter group action on the product of root systems
Current License: CC BY-SA 4.0
4 events
| when toggle format | what | by | license | comment | |
|---|---|---|---|---|---|
| Dec 8, 2018 at 2:14 | comment | added | Sam Hopkins | @RichardLyons: very good point. I think what I should’ve said is that if the roots form a simple system for the intersection of the root system with the subspace they span, then they are part of a simple system for the whole root system. | |
| Dec 7, 2018 at 23:38 | comment | added | Richard Lyons | @SamHopkins In G_2, two roots inclined at 2$\pi$/3 are not part of a simple system. | |
| Dec 7, 2018 at 15:15 | comment | added | Sam Hopkins | I don't think it can possibly be transitive: if $\alpha$ and $\beta$ are orthogonal, then $w\cdot \alpha$ and $w\cdot\beta$ will have to be orthogonal too. | |
| Dec 7, 2018 at 14:39 | history | asked | Jianrong Li | CC BY-SA 4.0 |