Timeline for Decomposition into Weyl modules
Current License: CC BY-SA 3.0
9 events
| when toggle format | what | by | license | comment | |
|---|---|---|---|---|---|
| Mar 14, 2018 at 11:38 | vote | accept | Michiel Van Couwenberghe | ||
| Mar 13, 2018 at 9:08 | history | edited | Michiel Van Couwenberghe | CC BY-SA 3.0 |
improved citations
|
| Mar 13, 2018 at 8:47 | comment | added | Wilberd van der Kallen | Basic example: conjugation action of SL2 on two by two matrices in characteristic two. Find the filtration. | |
| Mar 12, 2018 at 20:15 | comment | added | Jim Humphreys | @Michiel: The ordering of Weyl modules in a Weyl filtrattion suggested in your edit isn't always possible, as shown in my rank one example. The main point of introducing these filtrations is to study injective modules, or tilting modules, for $G$ in cases where the modules are indecomposable. | |
| Mar 12, 2018 at 18:07 | answer | added | Jim Humphreys | timeline score: 8 | |
| Mar 12, 2018 at 16:31 | history | edited | Michiel Van Couwenberghe | CC BY-SA 3.0 |
corrected mistake
|
| Mar 12, 2018 at 15:33 | comment | added | Michiel Van Couwenberghe | @JeremyRickard Hmmm, you might be right. I think I want the $\lambda_i$ ordered such that $\lambda_i < \lambda_j$ implies $i < j$ but I am not sure whether that is possible. | |
| Mar 12, 2018 at 14:38 | comment | added | Jeremy Rickard | I don’t understand your second paragraph. The results you quote don’t rule out a module $V$ with a Weyl filtration $0=V_0<V_1<V_2=V$ with $V_1/V_0\cong V(\mu)$, $V_2/V_1\cong V(\lambda)$, $\mu>\lambda$ and $V\not\cong V(\mu)\oplus V(\lambda)$. | |
| Mar 12, 2018 at 14:26 | history | asked | Michiel Van Couwenberghe | CC BY-SA 3.0 |