Mathematics

Associated with Math.SE; for both general discussion & math qu...
Oct 31, 2012 13:52
I guess a surjection is like a finite colimit or something
Oct 31, 2012 13:51
is it clear why a functor "preserving surjections" is the same thing as "preserving colimits"?
Oct 29, 2012 21:31
@Dedalus what is the indexing category of the kernel?
Oct 29, 2012 21:18
with the terminal object being the kernel
Oct 29, 2012 21:17
what is the indexing cat for the kernel? isn't it isomorphic to the standard kernel diagram?
Oct 29, 2012 21:16
Since the kernel diagram is finite then, the indexing limit guy is finite?
Oct 29, 2012 21:15
Can someone tell me what it means for a kernel to be a finite limit? I know it is a categorical limit, but why finite?
Oct 10, 2012 14:59
i retract my questions @anon. i think...
Oct 10, 2012 14:59
$M$ is artinian, so i think this makes sense
Oct 10, 2012 14:58
i want to say that $M/something$ has smaller length than $M$. So $M$ is generated by two guys, $u$ and $v$. The idea I'm told to consider is that you want to find a submodule of $Ru$ which is simple, call it $Ruy$. Then considering $M/Ruy$ has length less than $M$
Oct 10, 2012 14:56
the point is this...
Oct 10, 2012 14:56
i told you they were dumb questions
Oct 10, 2012 14:56
right...
Oct 10, 2012 14:55
can $Ru$ have nontrivial submodules?
Oct 10, 2012 14:53
cyclic means generated by one guy
Oct 10, 2012 14:53
implying it's not obviously cyclic, but saying that you can at least say it has a cyclic submodule
Oct 10, 2012 14:52
i was looking at an argument which inducts on the length of a module. one supposes $M$ is generated by two elements, so that $M=Ru+Rv$. We want to show that $M$ is actually cyclic, generated by one guy. But the argument goes that $Ru$ has merely finite length
Oct 10, 2012 14:50
a cyclic module
Oct 10, 2012 14:50
Isn't $Ru$ cyclic by definition and thus can have no submodules?
Oct 10, 2012 14:49
Let $M$ a module over $R$ generated by two elements, $u$ and $v$, such that $M$ has a finite length, say $r$. It is trivial to say that $Ru$ has length 1, no?
Oct 10, 2012 14:48
@anon can i ask you two dumb ring/module theory questions?
Oct 10, 2012 14:29
M=<a,b>? M=Ra+Rb? What is more standard
Oct 10, 2012 14:28
is there a compact way to write that a module M is generated by two elements a and b?
Oct 2, 2012 14:55
I should have gotten that thank you. What a gyp.
Oct 2, 2012 14:54
No?
Oct 2, 2012 14:51
$\pm$
Oct 2, 2012 14:21
Not if your category is a fuzzy category
Sep 25, 2012 20:03
if $I$ is a compact interval are integrals of functions $f\in C(I)$ continuous functions of $f$? Is the integral a continuous operator? Does that even have meaning?
Sep 25, 2012 14:43
Is the space of all maps from a group to the circle compact? Is there some natural topology in which to make sense of that?
Sep 25, 2012 14:39
i'm the author of the local-global principle. i don't do latex
Sep 25, 2012 14:38
i will walk out of lectures that do not correctly attribute his name, and instead replace it with a vulgar Americanism. :snob:
Sep 25, 2012 14:38
i insist on Григо́рий Я́ковлевич Перельма́н for Perelman
Sep 25, 2012 14:35
when I'm in Old Germany I do as the Old Germans do. i haven't been there in awhile, though
Sep 25, 2012 14:32
it doesn't help, because i have no use for small latin letters not in the English alphabet when writing people's names
Sep 25, 2012 14:31
must we write chinese authors names in the original ideogram?
Sep 25, 2012 14:30
people who use beta for the ss annoy me
Sep 25, 2012 14:30
Wirestross