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Jul 21, 2019 at 6:28 vote accept Ester
Jul 21, 2019 at 6:27 comment added Ester @Victor Thanks Sir. Your answer is quite helpful.
Jul 20, 2019 at 23:14 comment added Victor Protsak @Ester I apologize for the gender mix-up. I have converted my comments into an answer and provided some additional details. This is as far as I am willing to go, and even a bit beyond that. Good luck with your project!
Jul 20, 2019 at 23:08 answer added Victor Protsak timeline score: 3
Jul 20, 2019 at 17:01 comment added Ester Can you please provide a bit more detailed answer?Thank you.
Jul 20, 2019 at 16:50 comment added Victor Protsak The last statement is a general property of multigraded rings, where the grading abelian group is the root lattice. I don't have Miller-Sturmfels book close at hand, but that will be a natural reference to check.
Jul 20, 2019 at 16:37 comment added Victor Protsak Yes, we need finite generation of $U$ as a right $U_0$-module. The algebra $U$ is almost commutative (i.e. its associated graded algebra ${\rm gr\,}U$ is commutative and generated by degree 1 part) and the adjoint action of $\frak h$ is semisimple and preserves the filtration. So it is sufficient to prove the corresponding statement for the associated graded algebra: $S_{\lambda}$ is a finitely generated $S_0$-module.
Jul 20, 2019 at 15:58 comment added Ester No problem at all!
Jul 20, 2019 at 15:52 history edited YCor CC BY-SA 4.0
edited title
Jul 20, 2019 at 15:52 comment added YCor "Finite-dimensional simple Lie algebras" is not specific enough, I edited the title.
Jul 20, 2019 at 14:21 history edited Ester CC BY-SA 4.0
edited title
Jul 20, 2019 at 13:00 history edited Jim Humphreys
edited tags
Jul 20, 2019 at 12:55 answer added Jim Humphreys timeline score: 1
Jul 20, 2019 at 7:11 comment added Ester I have been trying to prove that it is finitely generated for a number of days using the PBW theorem, but it has always evaded me. I know that proving your statement will give the desired result(though I needed the fact it is finitely generated as a right module). Can you please provide at least a sketch of the proof of your assertion here or in some other medium?Thank you.
Jul 19, 2019 at 23:42 comment added Victor Protsak Yes, here is the last instance. The answer is affirmative and follows from the fact that $U_{\lambda}$ is a finitely generated left module over $U_0$, where the subscipts denote the grading of the universal enveloping algebra $U$ with respect to the adjoint action of the Cartan subalgebra. (There is too much notation for me to type a proper answer on a tablet.)
Jul 19, 2019 at 18:20 history edited YCor CC BY-SA 4.0
added tag, removed capitals
Jul 19, 2019 at 18:19 history edited Ester CC BY-SA 4.0
deleted 1 character in body
Jul 19, 2019 at 18:15 review First posts
Jul 19, 2019 at 19:21
Jul 19, 2019 at 18:12 history asked Ester CC BY-SA 4.0