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seen Nov 26 at 17:03

Math Grad Student


Jul
6
comment An elegant description for graded-module morphisms with non-zero zero component
Well, I don't remember. I do remember that I was localizing by these morphisms and that was what I meant by quotienting. Judging by the date, I was probably trying to work out a ncag example. I don't have a clue what it was!
Aug
25
comment Why do we use the commutator bracket for Lie algebra's
Yes, B R this is also a nice point. Although somehow that seems to depend on some of the other facts. In particular, we define Lie alg reps to be compatible with the structure, which is the Jacobi identity...
Nov
25
comment Interesting calculus problems of medium difficulty?
@Srivatsan did you consider it for f(x)=x?
Jul
23
comment Equalizers in category of sets/graphs — a couple of examples
Using latex and a more standard mathematical presentation style. In particular, don't be afraid to write sentences.
Jul
20
comment What is the name of the vertical bar?
@Zhen Lin, I would say that depends on the usage, I have no spacing issues for using it in set-builder notation or restrictions. Moreover you forgot to mention the \left. However we are deviating quite far from the point of the question. My comment was meant as a joke.
Jul
20
comment What is the name of the vertical bar?
it's called \mid, at least if you are a TeXnitian. :)
Jul
8
comment Direct sum of an algebra and its opposite
@Pete L. Clark, yes, this is definitely the thrust of my question, why the heck is it the universal enveloping algebra of anything?
Jul
7
comment Direct sum of an algebra and its opposite
ok great. Thanks.
Jul
7
comment Direct sum of an algebra and its opposite
Yes, that is a good point about dimensionality. Can you point me to a statement of this so I can at least remember what I was thinking of?
Jul
6
comment How to draw a weight diagram?
You have a lot of questions here, and maybe someone will come along and answer them all systematically for your specific example(though you don't tell us what n is), but let me just say this: take a look at chapter 12 of Fulton and Harris, books.google.com/…, I think that reading through this example will make this more clear.
Jun
9
comment Mathematical precise definition of a PDE being elliptic, parabolic or hyperbolic
@Willie Wong, You're awesome.
Jun
4
comment What is the connection between Grothendieck's Differential Operators and Hochschild Cohomology
Sorry, but I have a few more questions, first is $\mathcal{O}$ the same as $A$ here? Second, what do you mean de Rham of $A$? If you mean de Rham on the variety with coordinate ring $A$, then how is that different than the topological de Rham. Sorry if these questions are stupid.
Jun
4
comment What is the connection between Grothendieck's Differential Operators and Hochschild Cohomology
hehe, thanks @Pete L. Clark and @Mariano, the edit was what I intended. :)
May
17
comment Lifting maps of quotient modules
Right again... sorry.
May
17
comment Lifting maps of quotient modules
Both maps are morphisms in $R$-mod.
May
17
comment Lifting maps of quotient modules
@Jack Thanks, you are right, $\bar{R}$ is not unital. I am not sure what structure you are asking about though.
May
11
comment In (relatively) simple words: What is an inverse limit?
I too think of the Cauchy sequences analogy. This was suggested to me by D.N. Yetter. Good answer +1. Especially the last line, it is catchy and mnemonous.
May
10
comment Do localization and completion commute?
Didn't you just ask this on MO and get an answer.
May
8
comment references for learning about branch cuts/ branch points in complex analysis
Yayaya! Cool reference. +1!
May
5
comment String Theory: What to do?
Wow, biased much?