Search Results
Search type | Search syntax |
---|---|
Tags | [tag] |
Exact | "words here" |
Author |
user:1234 user:me (yours) |
Score |
score:3 (3+) score:0 (none) |
Answers |
answers:3 (3+) answers:0 (none) isaccepted:yes hasaccepted:no inquestion:1234 |
Views | views:250 |
Code | code:"if (foo != bar)" |
Sections |
title:apples body:"apples oranges" |
URL | url:"*.example.com" |
Saves | in:saves |
Status |
closed:yes duplicate:no migrated:no wiki:no |
Types |
is:question is:answer |
Exclude |
-[tag] -apples |
For more details on advanced search visit our help page |
Non-commutative rings and algebras, non-associative algebras. Can be used in combination with ra.rings-and-algebras
8
votes
Accepted
$M$ is finitely generated as $A$-module iff $M/A_{>0}M$ is finitely generated as $A$ module?
This is essentially Nakayama's lemma (not literally, but the same proof). More generally, the result is that a graded module map $\phi\colon N\to M$ is surjective if and only if the induced map $N\to …
2
votes
Accepted
Graded category O for for rational Cherednik algebras, but at t=0
This is extremely false: for generic $\mathbf{c}$, the algebra $H_{0,\mathbf{c}}(W)$ is Morita equivalent to the functions on Calogero-Moser space, a finite dimensional smooth affine variety, and cate …
6
votes
Accepted
Jacobson radical = intersection of all maximal two-sided ideals
Yes, this is true; it's essentially just a restatement of Artin-Wedderburn. All you need to do is note that by Artin-Wedderburn, a finite dimensional algebra with trivial Jacobson radical is a sum of …
7
votes
What is an example of a ring in which the intersection of all maximal two-sided ideals is no...
A very important example is the quotient of $U(\mathfrak{g})$ (where $\mathfrak{g}$ is a simple complex Lie algebra) by the central elements killing a finite dimensional representation. This has a un …
4
votes
How canonical is the triangular decomposition of a rational Cherednik algebra?
Perhaps part of the confusion is that you didn't actually discuss triangular decompositions at all (that certainly confused me at first). A triangular decomposition for a Cherednik algebra comes from …
14
votes
Definition of an algebra over a noncommutative ring
I would argue that this notion doesn't have one natural generalization. One obvious one is what I would call an $R$-bimodule algebra, that is, an algebra which is an R-bimodule in such a way that lef …
14
votes
When does the converse to Schur's Lemma hold?
I assume you're allowing A to be non-commutative. In this case, things can go wrong in all kinds of ways. For example, all Verma modules have endomorphisms given by $\mathbb{C}$, but loads of those …