Jun 13, 2022 09:12
As someone who has been on and off with alcohol in my lifetime, people like that are so annoying.
 

 Mathematics

Associated with Math.SE; for both general discussion & math qu...
Feb 25, 2019 20:46
ok no problem
Feb 25, 2019 20:46
Does that make sense? I feel like I worded that poorly. Basically take the thing you want to be a functor and use it to define the category so that the "functor" is a functor. Or would that route be poorly behaved
Feb 25, 2019 20:45
@AlessandroCodenotti could we also perhaps be perverse and just define the functor $F$ that yields a sheaf of $A$-modules, and then just define the essential image to be a category where we only specify the maps $F(i)$ where $i$ was a morphism in $OP(X)$.
Feb 25, 2019 20:42
ok, cool that is the kind of answer I am looking for.
Feb 25, 2019 20:40
" a sheaf of O-modules or simply an O-module over a ringed space"
Feb 25, 2019 20:40
In mathematics, a sheaf of O-modules or simply an O-module over a ringed space (X, O) is a sheaf F such that, for any open subset U of X, F(U) is an O(U)-module and the restriction maps F(U) →F(V) are compatible with the restriction maps O(U) →O(V): the restriction of fs is the restriction of f times that of s for any f in O(U) and s in F(U). The standard case is when X is a scheme and O its structure sheaf. If O is the constant sheaf Z _ {\displaystyle {\underline {\mathbf...
Feb 25, 2019 20:33
Like, each module is a module over a different ring
Feb 25, 2019 20:27
Quick question, something I never realized. If A is a sheaf of rings, and F is a sheaf of A-modules, what category does F take values in?
Feb 11, 2019 00:50
Haha it was actually a really cool class. It was the lead in to Sobolev spaces
Feb 11, 2019 00:49
I told this man he was off his rocker and weak derivatives were nonsense
Feb 11, 2019 00:49
I somehow got roped into this crazy analysis class once and the proff tried to teach us about functions that were $\pi$ times differentiable
Feb 11, 2019 00:47
hard no
Feb 11, 2019 00:47
no
Feb 11, 2019 00:42
My parents are in PS right now
Feb 11, 2019 00:41
@Ultradark I am pretty amateur in algebraic geometry, I am just reaching modern AG
Feb 11, 2019 00:41
Definitely not the highest spot, more like the lowest spot
Feb 11, 2019 00:40
yeah I am downtown Seattle
Feb 11, 2019 00:39
I am in Washington and would prefer it stop snowing
Feb 11, 2019 00:36
While passing time throughout the snow blizzard
Feb 11, 2019 00:35
I am just trying to fit in
Feb 11, 2019 00:35
wait I thought it was common for sub-par aspiring algebraic geometers to make snide remarks about things just because they don't have any background, but play it off like the things aren't cool enough
Feb 11, 2019 00:30
Theres a snow blizzard where I live I am stuck inside here listening you all talk about science particle
Feb 11, 2019 00:26
Well this conversation looks boring. No offense. Sounds science-y
Feb 11, 2019 00:23
I am not sure how that site works though, so maybe thats normal.
Feb 11, 2019 00:22
Does anyone know if nLab was heavily edited within the last year? I am looking at some pages I read maybe 4 - 8 months ago and they all seem different.
May 25, 2018 04:58
Thanks @MatheinBoulomenos
May 25, 2018 04:57
Immediately we see a_1 must be +/- 2, but the choice of -2 contradicts the fact that f(0) > 0, so the only solution is the one you found
May 25, 2018 04:56
Composing f with itself yields f(f(x)) = a_0(1+a_1)+a_1^2x
May 25, 2018 04:55
@silent you get immediately that degree of f is at most 1 so f can be written in the form f = a_o + a_1x
May 25, 2018 04:43
It seems to make sense because the thing remaining to check would be that the inclusion composed with F is naturally isomorphic to the identity functor on C’, but that would just be the restriction of the identity functor on C? So essentially I would be checking that F restricted to C’ and identity restricted to C’ are naturally isomorphic but doesn’t that follow from the fact that they were naturally isomorphic over C
May 25, 2018 04:40
If I have a category C and a subcategory C’ and I define a functor F: C —> C’ and I show that F composed with the inclusion functor i: C’ —> C is naturally isomorphic to the identity functor on C, is that enough to conclude and equivalence of categories between C and C’
May 24, 2018 07:57
I’m pretty perverse most of the time it probably just looks like me
May 24, 2018 07:54
most of the names that seem to suggest some physical or visual interpretation make sense to me in some way, but I couldn’t picture what a flabby sheaf should look like
May 24, 2018 07:51
I like that answer
May 24, 2018 07:47
So what’s flasque about a flasque sheaf!
May 24, 2018 07:43
Can anyone give me the quick and dirty on what is flabby about a flabby sheaf?
May 21, 2017 03:45
Even though it technically is, the other ring being the field of fractions, but we dont talk about A being integrally closed with respect to some ring B
May 21, 2017 03:44
I got the vibe that they mean it is not "with respect to some other ring"
May 21, 2017 03:43
Does anyone have an idea what is meant by "without qualification"?
May 21, 2017 03:43
Comin' in guns hot with a question: In Atiyah - Macdonald they say "An integral domain is said to be integrally closed (without qualification) if....."
May 18, 2017 04:23
Im working out of atiyah macdonald, they define it by universal property
May 18, 2017 04:19
I have always just accepted that it would be the case otherwise the property would be useless... but I tried to come up with an easy justification of why it would be true and I actually dont really have anything
May 18, 2017 04:17
Amateur hour question over here: Can anyone give me the spark notes proof of why if two modules are isomorphic, if one is flat so is the other?
May 12, 2017 05:30
I guess I'll just do what I should do... and try to prove it : 0
May 12, 2017 05:29
No problem :) thank you for that information!
May 12, 2017 05:28
this is probably a no brainer but I have 0 topology background
May 12, 2017 05:27
Sorry for coming in guns hot with a question, but I dont feel like its worthy of a post on MSE - are minimal primes preserved through a homeomorphism of spectrum?
 
Feb 1, 2018 09:44
In my experience, there are times when figuring out the answer to extreme hypothetical questions can save the person from having to ask 10x as many questions about realistic scenarios, because the answers follow from the extreme cases
Feb 1, 2018 09:44
I am not a regular user on “MoneySE”, but I don’t see why this question seems ill received just because the scenario is so improbable. I like the question, not because I’m learning about “what to do in the case no transactions taking place for a stock” but because the hypothetical scenario is helping the OP (and me) make sure we know exactly what causes a stock price to fluctuate. If you’re going to build an investment strategy with the goal of making Money and making money directly depends on the fluctuations of stock prices - knowing the mechanics of the fluctuations seems like a good idea