Skip to main content

Timeline for Maximal Submodule of a Verma Module

Current License: CC BY-SA 3.0

13 events
when toggle format what by license comment
Oct 28, 2014 at 13:02 history edited Jim Humphreys CC BY-SA 3.0
added 528 characters in body
Dec 17, 2013 at 15:09 comment added Jim Humphreys @Bib: I'm not requiring $\mu$ to be minimal in such a set of weights, only asserting the existence of a subweight $\mu$ having "bad" $N(\mu)$. Locating such $\mu$ can be subtle. The difference between linkage and strong linkage of weights is crucial here.
Dec 17, 2013 at 10:24 comment added Bib You mention a converse statement in your 4th paragraph : μ has to be a minimal element of { η / [M(η);L(ν)]>1 } or am i wrong ? Thanks
Dec 9, 2013 at 9:44 vote accept Bib
Dec 9, 2013 at 0:07 history edited Jim Humphreys CC BY-SA 3.0
added 266 characters in body
Dec 8, 2013 at 14:29 history edited Jim Humphreys CC BY-SA 3.0
added 1654 characters in body
Dec 5, 2013 at 14:01 comment added Jim Humphreys @Vit: Here I only look at resolutions of simple highest weight modules (not necessarily finite dimensional) using direct sums of Verma modules. (See Remark 6.5 in my book for more detaile.)
Dec 5, 2013 at 3:13 comment added Vít Tuček The answer in general of course depends on what exactly one means by "BGG-type resolution". The only result that goes in this direction that I know of is arxiv.org/abs/math/0604336 But they work in the category $\mathcal{O}$ attached to a parabolic subalgebra with abelian nilradical.
Dec 4, 2013 at 18:45 history edited Jim Humphreys CC BY-SA 3.0
added 303 characters in body
Dec 4, 2013 at 17:05 comment added Jim Humphreys A side remark is that I've never seen usable conditions on a weight determining whether or not $L(\lambda)$ has a BGG-type resolution. There are obvious examples beyond the dominant integral case, but it doesn't seem possible to organize them nicely. Such a resolution would start with the maximal submodule of a Verma module and then try to proceed with Verma submodules. But usually the character formula for $L(\lambda)$ can't be as nice as the one given by Weyl-Kostant.
Dec 4, 2013 at 14:58 history edited Jim Humphreys CC BY-SA 3.0
added 256 characters in body
Dec 4, 2013 at 14:06 history edited Jim Humphreys CC BY-SA 3.0
added 81 characters in body
Dec 4, 2013 at 13:57 history answered Jim Humphreys CC BY-SA 3.0