MO editors' lounge

« first day (2418 days earlier) ← previous day next day → last day (1472 days later) »

6:21 AM

@MartinSleziak actually it sounds redundant with schubert-calculus which already currently exists in 55 questions (in addition schubert-cells: 9 questions, and schubert-varieties: 26 questions are tightly related).

Martin Sleziak

@YCor Personally I do know enough about this topic to be able to judge whether or not the tag is going to be useful.

It is possible that the OP will ignore my suggestion - and without the tag-wiki and having only single question, the tag will be removed after 6 months by the SE software.

Or, if you really consider the tag redundant, you can remove it from the question or leave a comment to the OP about this.

dead-link One of the link in that post is dead: igm.u-pem.fr/~al/ARTICLES/ChernYang.ps.gz I have mentioned this at least in a comment - if the question is bumped, the link could be edited directly into the post.

One of the links in this post seems to be dead. It still exists in the Wayback Machine. — Martin Sleziak 38 secs ago

Martin Sleziak

6:45 AM

specific-question I guess hecke-algebras would be a reasonable tag for this question: What is the relationship between Hecke algebras and the enveloping algebra of Lie groups? However, all five slots are already taken.

Q: What is the relationship between Hecke algebras and the enveloping algebra of Lie groups?

(originally posted in math stackexchange, but I deleted that post when I saw it had no responses.) Here is the story as I see it. Let $G$ be either an abelian td-group or an abelian locally compact group. Then the (spherical) Hecke algebra for $K=1$ is by definition automorphism group of $l^2(G...

1 hour later…

Martin Sleziak

7:50 AM

In my opinion, this is one of the challenges of creating a reasonable tag system on Stack Exchange site. If there are only large tags, searching is more difficult. (Still, they are important - they help categorization, they have more follower and improve visibility of questions.) Smaller tags are very useful when searching for some topic. But if there are too many very specific tag, often it we will run out of space when tagging questions - since there can only be five tags.

Meta Stack Exchange: Why is there a limit to the number of tags?

2 hours later…

YCor

9:23 AM

@MartinSleziak (on adding hecke-algebra) all these tags look good, I'd remove none of them. Or maybe fourier-analysis as a bit redundant to harmonic-analysic and a bit more inclined to classical analysis.

4 hours later…

Martin Sleziak

1:10 PM

new-tag A new tag azumaya-algebras was created by YCor, including a tag-excerpt.

Azumaya algebra

In mathematics, an Azumaya algebra is a generalization of central simple algebras to R-algebras where R need not be a field. Such a notion was introduced in a 1951 paper of Goro Azumaya, for the case where R is a commutative local ring. The notion was developed further in ring theory, and in algebraic geometry, where Alexander Grothendieck made it the basis for his geometric theory of the Brauer group in Bourbaki seminars from 1964–65. There are now several points of access to the basic definitions. == Over a ring == An Azumaya algebra over a commutative ring R is an R-algebra A that is free and...

Q: An example of an Azumaya algebra that isn't free over its centre

Azumaya originally defined an Azumaya algebra (which he called a proper maximally central algebra) to be an algebra A which is a free module of finite rank over its centre Z such that the natural map $$A\otimes_Z A^{\mathrm{op}}\to \mathrm{End}_Z(A)$$ is an isomorphism. More modern definitions (e...

ra.rings-and-algebras azumaya-algebras

Q: Are differential forms related to Azumaya algebras?

While studying vector bundle valued differential forms, $\Omega^{\bullet}(M, E)$, or $\Omega^{\bullet}(M, \mathrm{End}(E))$ if that helps this discussion, I've come across some work in Azumaya algebras. Thinking of $\Omega$ as an $R$-module, taking values in a bundle, and reading about how Azuma...