Timeline for Number of triples of roots (of a simply-laced root system) which sum to zero
Current License: CC BY-SA 3.0
6 events
| when toggle format | what | by | license | comment | |
|---|---|---|---|---|---|
| Nov 30, 2016 at 20:22 | comment | added | Jim Humphreys | @L Spice: Somehow the link got distorted, so here's another try: numdam.org/numdam-bin/fitem?id=PMIHES_1966__30__115_0 | |
| Nov 30, 2016 at 18:42 | comment | added | LSpice | The link got mangled; it should point to Springer - Some arithmetical results on semisimple Lie algebras. | |
| Nov 6, 2015 at 19:42 | comment | added | Jim Humphreys | @user: I'm not sure what comes out of the theory about this, but you can find explicit lists of positive roots (by height) for most of the irreducible exceptional types at the end of Springer's 1966 IHES paper: numdam.org/numdam-bin/fitem id=PMIHES_1966__30__115_0 (presumably you could check other cases using Bourbaki's descriptions of root systems) | |
| Nov 6, 2015 at 16:32 | comment | added | user | Can heights (ht) of special roots take all values in $\{1,2,\ldots, \rm{ht}(\theta)\}$? In other words, is it true that for every level of height, there exists at least one special root? I don't even know yet for simply-laced root systems. | |
| May 29, 2011 at 2:27 | comment | added | Yuji Tachikawa | Thank you very much! It's such an honor to have your response! | |
| May 28, 2011 at 19:20 | history | answered | Jim Humphreys | CC BY-SA 3.0 |