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00:00 - 15:0015:00 - 00:00

00:02
Btw Mike, do you actually speak French?
I assume you do, because of your profile.
No. I can read some French.
Ah, okay.
I've been on-and-off reading Grothendieck's memoirs
I just like that poem.
Ah, too much for me.
It's extremely interesting, to me.
Ah, really? That's a shame! He writes very poetically
Too much category theory, that is.
00:05
He doesn't write about technical matters in at least the first parts.
It's about his philosophy of mathematics
And it's really, really beautiful to me
Have you read Thurston, on proof and progress?
I have
It's nothing compared to Grothendieck, IMO
(it's also a LOT shorter!!!)
Probability question, in case anyone here might know how to answer my question
3
Q: Equality vs. Equality in Distribution ($t$-distribution for example)

ClarinetistA technical question that came up to mind as I was reading up on linear models today. Consider the $t$-distribution with $\nu$ degrees of freedom ($t_\nu$) for example. Let's say $T \sim t_{\nu}$; that is, the random variable $T$ follows this distribution. Does it mean that $T$ must equal $\dfr...

00:07
@MikeMiller And it's about very different things.
Grothendieck purely writes about his experiences
He doesn't really talk about a sense of progress
More about mathematical visions, types of mathematicians (maybe you've heard about this passage about building houses etc), long-term goals
Yes. I've heard most of those quotes an annoying number of times.
@MikeMiller That's a real shame.
It's nicer in French than English (I assume you heard the translations)
Hi @MikeM @Clarinet
Hullo
00:11
Back on your phone, Mike?
Hi @Danu
At home.
I hate this terrible cough I've got now :\
I hadn't been sick for 3+ years before moving here
Now I've been sick twice in 18 months
Sounds like the yuck that's gone around the US, Danu.
usually when somone overtrusts his healthy state for a good period of time, thats immunity hoodwinking
00:28
How'd all your lectures go, Mike?
Fine. Now prepping for meeting on Wed.
See if I can get through this monster of a paper by then...
The G&H group meets in an hour.
I thought it was a group of 2?
Kevin whined so we had to let him in.
00:31
LOL... I'm sure he'll contribute plenty :)
Jason Starr's talk was very pleasant, as was his wife's afterwards. Hyperkahler geometry is just too dang neato.
Ah, wish I knew more.
Something I learned in the algebra seminar last week: the torsion in $H^3(X;\Bbb Z)$ is a birational invariant.
For what X?
Complex variety.
00:34
Hello @Ted
Dinner time. BBL!
Idea: birationally equivalent complex varieties are related by a zigzag of blowups. At each of these stages you replace some subvariety $Z$ with $Z \times \Bbb P^k$. Kunneth says $H^3_{tors}(Z \times \Bbb P^k) = H^3_{tors}(Z)$.
Hi @Ted and @Mike ^_^
Hi @Khallil. Not quite uour face, but the new av is moving closer.
There's a homotopy between my the loop containing my face and hers and the constant loop, @MikeMiller. :-)
I've been reading some complex analysis but I can't seem to get any geometry from harmonic functions on open subsets of $\Bbb{R}^n$. Is there much to be gleaned, @MikeMiller?
00:44
Yes, but usually on "compact manifolds" (like a sphere or torus), and it's not obvious how.
Riemannian geometers seem to often be interested in the eigenvaluees of the laplacian.
I'm guessing that's where spherical harmonics pop up.
Reading up on the eigenstuff, it goes over my head a fair bit.
Mine too.
I find the stuff with nice geometry (that I can see at my current level) a bit more entertaining.
Like how harmonic functions relate to $\Bbb{C}$.
00:50
I would stick with that for now. The geometry of the Laplacian is s bit complicated.
What's the major difference between a set being connected and simply connected, @MikeMiller?
@Khallil: They're just different notions. The second notion is much stronger.
"There is a path between any two points" becomes "There is a path between any two paths"
Ah. So simple connectedness requires homotopy but connectedness just requires a path to exist between any two points?
So e.g. an annulus would be connected but not simply connected because you'd eventually need to cross the segment that's been cut out from a circle.
@Khallil: Not a good avatar. I propose a better one: encrypted-tbn0.gstatic.com/…
Hey @Balarka! I suppose it's better in some respects but I'll stick to the current one for now :-b
01:00
@Khallil: Yes.
I think there're much worse better images of Croc, but oh well.
Wicked!
Another way of thinking of it. Connectedness is demanding that there be a path between any two points. S.c. demands that it be unique up to homotopy. This matters eg if you wanted to define a log.
Or an antiderivative.
Does unique up to homotopy mean that we could define an equivalence class of some kind on all the paths between two points, @MikeMiller?
Yes, homotopy is an equivalence relation between paths with fixed endpoints.
Unique upto homotopy means that any two paths with same endpt are homotopic.
or, equivalently, any two paths with same endpoint belong to same equivalence class.
01:05
That's wicked.
@Danu Gromov's ICM talk beats Grothendieck's stuff :P
I'm just going off the definition of homotopy you gave me a while back.
I managed to find an identical one in some complex analysis notes I bought last year.
In the sense that most of it was like Beckett's imagination dead imagine to me.
01:27
Could someone of you take a look at the edit part of my question and tell me if it is correct?
3
Q: Equivalent conditions

Mary StarI am looking at the following exercise: Show that the following are equivalent conditions on a surface patch $\sigma (u, v)$ with first fundamental form $Edu^2 + 2F dudv + Gdv^2$ : $E_v = G_u = 0$. $σ_{uv}$ is parallel to the standard unit normal $N$. The opposite sides of any quadrilateral f...

@TedShifrin I feel weird this semester I have 5 days break and only 2 days of school
I better not slack off though I am starting this semester working very hard.
and organized and stuff
01:45
yooooooo
hola
how goes the math ppl?
:D
Hey all! I've taken some really informal undergraduate courses in calculus, and a tiny bit of differential equations, but I want to take a really formal approach to my education. Since I'm mostly self teaching at this point, does anyone know what the best books or online courses might be for me to check next?
@StanShunpike it goes well! Just returning from JMM :)
noice :D
Better yet, does anyone know a good rigorous calculus text?
@AliasUser The usual follow-up to those classes would be analysis and algebra
Analysis will be pretty much be just that, a rigorous review of Calculus (at first)
So any real analysis text is probably good, but I'd definitely recommend Spivak and eventually Rudin
@D.ZackGarza thanks! I've been taking MIT OCW, but I don't know how those compare to the literature - any opinions?
01:50
Which particular class(es)? I can take a look at the topics and see
(P.S., before I forget, here is an excellent resource for this kind of question: math.stackexchange.com/questions/94827/… )
Although it's unorthodox, I'd recommend switching between any and all texts you find if possible, @AliasUser. I haven't yet found a single book that covers a lot in a way that's clear to me. It may be just me. Who knows?
@D.ZackGarza - it actually appears that MIT OCW doesn't have a scholar (= with tests and note) version of their analysis course - so books it is!
@Khallil - that sounds like a really good idea.
Ahh yep, the math selection on OCW is a bit limited at the moment
Hmm let's see, there is a good course on youtube, from Harvey Mudd
Here we go, the first video: youtube.com/… (they use Rudin, so it should be easy to follow along)
@D.ZackGarza - is it natural after multivariate calc to feel fuzzy on topics like line integrals? It feels weird multiplying by differentials in line integrals, and even taking integrals with other variables (besides that being integrated) feels weird...
Are Spivak and/or Rudin available online (possibly in an old version) in some legal manner?
Maybe, if only because they're a little abstract. You can get more practice with them in, say, a Physics class on electrodynamics. Or in Complex Analysis
01:59
Sweet - thanks so much @D.ZachGarza - so Spivak then Rudin?
As for those books being legally available, that I'm not sure of. There are definitely PDFs around, and university libraries likely carry one of them
Yep, sure - but I definitely agree with @Khallil above, don't hesitate to jump between various books
It definitely helps to find books that suit your learning style
And if you're looking for more, just poke through the #reference-request tag for whatever subject, lots of great recommendations
@dzackgarza
oops
@dzackgarza - thank you so much - this has been just driving me crazy for a while :)
Definitely understandable, haha.
Oh, yeah - and if you're feeling iffy about integrals, going through a solid course in differential equations will net you plenty of practice
02:42
@BalarkaSen how goes studying Ted's book?
03:07
weee
@太極者無極而生
Hi @Stan
hey Ted
mow many years does a PhD usually take?
@TedShifrin
PhD in some area of pure math
@Ted: Some of these arguments are nonsense. :)
03:23
@MikeMiller do you have an answer to my question?
@MikeM: You talking about G&H?
hey, for $t^3-3t^2+4$, what does t equal when the formula equals zero?
Hi @Forever: Depends on how much you start off knowing, the field, etc, but typically 4-6 years.y
Can you guess one answer, @edition?
@TedShifrin two.
@TedShifrin from looking at the function on a graph.
@TedShifrin is there ever a good reason to stay 6 years when you could finish in 5?
03:33
@edition: OK, you can check by plugging in 2. So $t-2$ is a factor.
can't you just test the different factors of $4$?
@Forever: Depends on quality and long-range professional goals.
That will only find integer roots.
some theorem of algebra says you can find roots of a cubic by looking at roots of the constant
oh only the integer roots
factors of the constant
so would staying an extra year be good if I want to do more research to add to my resume?
You can discuss that with your adviser.
I have some interesting results... but I feel I can do more
03:36
Support is also an issue.
yes but I do not think that is an issue with me
I have only been supported for 4 years
Talk with your adviser. If you're finishing this year, you should already have applied for jobs.
well I haven't. And it's going to be tough to do that this semester and write my dissertation at the same time
hey @TedShifrin
so maybe an extra semester would be a good idea anyway
03:39
Talk with your adviser, for sure.
Hi Karim ... Have a good trip?
yeah @TedShifrin it was super nice
the weather was super nice
but I didn't use my mind for long time when I am doing math now I feel slow
you know @TedShifrin this semester I have only tuesday and thursday classes
I am quite excited for this i will have more time to study
the applied algebra that I am taking this semester is actually pretty easy compared to grad algebra I took last semester.
Of course!
@Ted: Yup.
so depressing that I discovered a result in topology that was published last summer :(
what are the odds
some russian beat me to it
what kind of topology are you doig
doing @ForeverMozart ?
03:47
mostly I work with different types of connectedness
@MikeM: I complained about some before publication. Others have caught other things. Generally, intuition is good. I Do have a long list of errors/typos.
point set topology ?
@L33ter yes. also set-theoretic topology. I like this area because it has the most pathological spaces
oh cool
@MikeMiller would you be offended if I ordered a half-caf half-decaf coffee?
03:50
Do you care? :)
i guess not... I do it so that I can sleep at night
@MikeM: I think you'll find at least one of my exercises that asked for the flaw in a certain proof in G&H. Not that I remember.
@Ted: Some very very sketchy (or nonsense) proofs after they defined analytic subvarieties. We moved on.
They're slower than me so right now they're fradkng while I do other work
Random (funny, perhaps? or just sad?) vid of the day:
@TedShifrin hola!
04:01
Hmm, I Think those are basically right, @MikeM, but I'm traveling.
@Ted: One proof, as far as we can tell, doesn't actually prove anything at all. We can talk about it in a couple weeks.
@Stan: I think I have Chicago dates ... Something like May 23-6 ...
@TedShifrin Excellent! We can't wait to have you for dinner. :)
@edition: Divide your polynomial by $t-2$, and you'll have a quadratic. Then you can factor or use the quadratic formula.
@edition
ted just said what I was about to say
04:07
What are you learning these days, @Stan?
is there a way to get paid enough to live on, just for doing research?
like 20k/year
cause I would do it
Not unless you're doing research that a company wants you to do ...
well nothing I do is useful
which is one of the reasons I got into this
I once did some useful stuff... but my conscience made me quit
that's a long story
Unless it was useful for killing people, i don't see why.
it just wasn't fun
I made more money that I will probably ever make again... but then I became interested in pure math
wall street related
some business practices I did not like
04:24
Oh, I get that.
Night, all!
see you later ted
@TedShifrin currently trying to understand Poisson processes for my stats class.
Nite! Ttyl
I taught some of that in probability,,Stan. Cool stuff.
probability theory was not for me!
ate me alive
Indeed it is nifty. I am sure I will have questions. Been hanging out here ever since class started lolol
04:28
@StanShunpike this is a great place if you need help with a math course
very quick responses, and there are some very talented people here
@ForeverMozart indeed, people here are very very generous with sharing their brilliance! :)
@StanShunpike unlike Lounge<C++> at SO.
@StanShunpike Yep, I am surprised many of them post here. They could probably spend their time publishing papers
@edition really???? Ppl in most places on here I have met are helpful
Tho I have a tendency to stay clear troublemakers
So that helps
I find a lot of interesting problems here also
maybe they get no answers, but are fun to think about
I forget who said there are two types of mathematicians, those who pose interesting questions, and those who solve them
Erdos was both :)
04:37
Hahahaha
I think I am neither
I am just a casual observer
wannabe
are you an undergraduate?
@StanShunpike
Ya, currently econ and stats
With an interest in physics and music in my free time
Write a lot of music
@ForeverMozart what kind of math do u fancy?
I like algebraic graph theory and set theoretic topology
most of my research is in the latter
unfortunately, most of the things I discover have already been discovered
but it's a lot of fun
Graphs theory is cool. It's interesting how frequently people like to use trees to depict stuff
They come up in linguistics and music theory
yes, I have even been interested in topologies on trees lately
trees are really infinite graph theory
which is not covered in most courses
04:47
How so? In what sense are trees infinite? I don't think I have ever seen an infinite one
oh, well in standard graph theory, a tree is a connected acyclic graph on $n$ vertices
Yeah that makes intuitive sense and matches what I've seen
but in set theory we usually mean a tree is something like $2^\omega$
rather $2^{<\omega}$
that is the binary tree
Is that a power set?
@Clarinetist what about the probability two N(a,b) processes equal to each other. Example N(0,2) = N(0,4). I had the thought that these obviously must be equal to some integer $k$. I can obviously calculate the probability each individual counting process equals k over their respective intervals. Would it make sense to multiply those probabilities to find the likelihood of both happening?
05:17
i am going to sleep on the beach. the sun will wake me. goodnight
adios
I wonder whether asking how to effectively learn mathematics if you have a terribly bad memory is a constructive question.
@user276387
i'm back
couldn't sleep
let me give you an answer
but let me get a beer first
@user276387 memory is not so important. what is most important is that you can reconstruct proofs on the spot. this does not require memory, only simple logic
fantastic eh
06:06
@ForeverMozart Well it's just that sometimes I find asking myself astonishingly simple things, like the derivatives of sin(x) and cos(x), which one had the negative and similar things.
 
2 hours later…
08:02
hi
This question about circulant matrices looks interesting to me but is getting little love. Can anyone guess why? mathoverflow.net/questions/227774/…
0*0=0
1*1=1
2*2=2
...
?
08:46
Suppose that $N$ is the normal unit of a surface. Which is the relation between $N_u$ and $N_v$ ? Are they perpendicular?
09:13
@BalarkaSen So eh... do you read French?
09:27
@BalarkaSen Also, Gromov gave several such talk. Which one are you referring to?
hi.. anyone got any ideas about math.stackexchange.com/questions/1606536/… ?
Hello!!! @DanielFischer
Could you take a look at my question?
http://math.stackexchange.com/questions/1604974/is-it-a-solution-to-the-initial-equations
Hello @Khallil !!

I want to show that the unit sphere cannot be covered by a single surface patch.

We have that the unit sphere is the closed set $\{(x,y,z)\in \mathbb{R}^3 \mid x^2+y^2+z^2=1\}$.

By the definition of the surface, this set must be homeomorphic to an open set in $\mathbb{R}^2$, but since the above set is closed that cannot be true.

Is this correct?
09:53
@Danu Not really.
re:gromov "What is a Manifold?".
@BalarkaSen I think you have no idea what you're talking about then ;)
Last I remember, Grothendieck's memoir was not available in any other language than French.
I definitely haven't read Grothendieck memoir. I am just talking about the poetic way Grothendieck writes stuff.
I saw some of that from the translated Pursuing Stacks.
I haven't seen Pursuing Stacks; the memoir is really great.
I find Gromov decisively less "epic" (in what I've seen) :P
Can you explain what you mean by epic? Mathematically, his legacy in geometry & topology is comparable to Grothendieck. But yes, he is less dramatic than him.
In terms of style of writing (or in Gromov's case, speaking as well)
10:02
Well, I think in terms of writing he is far greater than Grothendieck. Remember that the highest level of art is nonsense art ;)
@BalarkaSen No?
I take it you're not into art?
I was merely joking. Half the time I can't understand Gromov's mathematico-philosophical (or biological) stuff.
Not that I understand much of his math.
I'm very wary of non-biologists attempting to revolutionize biology :P
Me too. :D
Gromov seems to be fairly careful, but even then...
10:05
To be honest, I don't find his paper of Cell division and Hyperbolic geometry very appealing.
@Danu: In any case, I agree Grothendieck's style of writing is quite beautiful. The only mathematician I know of comparable to him in that sense is Hardy.
Have you read A Mathematician's Apology?
@edition you too ?
@BalarkaSen Very thoroughly. I didn't like it much, mostly because I think he is wrong about many things in there!
@Danu That may be true. Can you give an example?
@BalarkaSen I think he had the misfortune of quoting relativity theory, of all, as a theory that would only be of theoretical importance.
...nuclear bombs proved him wrong.
(cont.)
Consider the set $S$ where it has axioms
a+ab=a
1a=a
a=/=b
0+a=a
a(b+c)=ab+ac
(a+b)c=ac+bc
(ab)c=a(bc)

Then

0(1)=0
0+1=1
0+0(5)=0
1+1=2
1+2=1+1(2)=1

To be checked: S=$\{0\}$ and other weird or contradictory results
Laters...
10:18
@Danu Oh, fair enough.
how its that 1+1=2 ?
I'd just take most of it as a set of personal thoughts and not literally.
@Idle001 2 is a successor of 1 just like the reals? (S is basically the axioms of reals plus a+ab=a). I am not sure how to verify that
@BalarkaSen Of course.
I wrote an in-depth essay based on it.
10:22
I found his criteria for what it means for a theory to be beautiful to be quite naive, in the end.
I think Rota's thoughts on it were more interesting.
@Idle001 I am trying to investigate what happens if an additive absorbing element is being introduced to the reals, and the absorbing element is a product of two non absorbing elements
Which Rota?
Gian-Carlo Rota (April 27, 1932 – April 18, 1999) was an Italian-born American mathematician and philosopher. == Early life and education == Rota was born in Vigevano, Italy. His father, Giovanni, a prominent antifascist, was the brother of the composer Nino Rota and of the mathematician Rosetta, who was the wife of the writer Ennio Flaiano. Gian-Carlo's family left Italy when he was 13 years old, initially going to Switzerland. Rota attended the Colegio Americano de Quito in Ecuador, and earned degrees at Princeton University and Yale University. == Career == Much of Rota's career was spent as...
@Secret but according to r eccentric definitions 1+1=1+1(1)=1 ?
@Idle001 Actually that's valid but a tricky one
Because a+ab=a demands a=/=b, but in this case we have the a=b=1 using that axiom

I am not sure how to get out of this one...
I am not sure if that's a sign that S is actually a singleton and nothing else
10:29
Sounds like you're wasting your time, to me...
I sometimes play with algebra and trying to understand how adding and removing axioms will affect the algebra

The problem is that, like when I do physics problems, I often lacked the intuition to see the expressions that are most important in order to investigate the important properties of the structure of the algebra
and thus often end up trying everything before finding the correct expression that can do the job
The problem is that for 1+1=1+1(1) by mutlplicative identity, the axioms does not seemed to tell what's the next step because the terms that made up the product are the same, thus it fall outside of the confines of the axiom a+ab=a
Perhaps I have overlooked something from the reals I should see if there are anything they that can simplify this expression further
@Danu So, what have you been doing lately?
@Secret in this case : 1+a is always 1 and this is not an anomaly following ur logic
I understand that because 1+a=1+1a=1
The problem is that for the case where a=1, how will 1+1 be evalued
because for that case any attempt to break apart 1 such that one element of the product is 1 will always result in both elements of the product to be the same element, 1
Let me first check how 1+1 is evaluated in the reals again...
Hmm seems in this case it is valid to define 1+1=2 because 1+1 is not under the confines of a+ab=a
now with that
1+2=1 by the derived result of 1+a
so it seems for this algebra addition seemed to revolve around the elements 0,1,2
I am suspecting additive inverses are not defined in this algebra
but it is not quite a finite field, hmm
$2+a=(1+1)+a=1+(1+a)=1+1=2$
$2+a=2+1a=2+(22^{-1})a=2+2(2^{-1}a)=2$
$$2+a=2(1)+a=2(a^{-1}a)+a=(2a^{-1})a+a=a+(2a^{-1})a=a+a(2a^{-1})=a$$
So S will be a singleton unless either one or more the following:
a+b=/=b+a
ab=/=ba

Therefore $S=\{0\}$
11:06
@BalarkaSen Holidays!
Ah, enjoy.
So in order to have an algebra with a+ab=a that is nontrivial and to retain as many real axioms as possible, either one or more of the commutative axioms have to go
@BalarkaSen They're over now...
@Danu Out of curiosity, are you familiar with the isoperimetric inequality?
@BalarkaSen Yes.
11:14
I was wondering about certain generalizations of it. E.g., take a graph and assign each edge a length of 1. Then you have a (geodesic) metric space. Length can be defined a usual by sup of sums of pieces, over all the partitions.
Now you can ask for loops in the graph with fixed length $\ell$ which bounds maximal area.
Have you encountered anything like this?
@BalarkaSen Think again: Do physicists care about graph theory?
@ Idle001 One of my maths hobby is: Take some nice mathematical object, e.g. the reals, add or remove an axiom, then determine what conditions or constraints such that the resulting object is still nontrivial
@Danu I was actually wondering whether you have seen a generalization for Riemannian manifolds, but I didn't explicitly say Riemannian manifolds because I don't know anything about it :)
Geodesic metric spaces are coarse (i.e., discrete) version of Riemannian manifolds.
@BalarkaSen No.
Dang. Ok.
Thanks.
I learnt the proof of isoperimetric inequality for $\Bbb R^2$ a few days ago, and I thought it was pretty neat.
Huy
Huy
11:46
@BalarkaSen: do you know anything about Cartan subalgebras?
Ehh, no.
@BalarkaSen I'd try to do it via a variational method.
I'm listening if you want to elaborate on that, I don't know much about calculus of variations. The proof I know uses Fourier theory. Modulo some tricks, it's a straightforward corollary of Parseval's identity.
(more precisely, you need the following lemma. If $f$ is a $C^1$ function on $[0, 2\pi]$ with $\int_0^{2\pi} f(x) dx = 0$ then $\|f(x)\| \leq \|f'(x)\|$ where the norm is the $L^2$ norm. Moreover you have equality iff $f(x) = a\sin(x) + b\cos(x)$ for $a, b$ some real. This can easily be proved using Parseval's identity)
I'm sure I can find it for you
12:01
Nice, I'd like to read the proof if you have a reference or something.
It relies on the same lemma
Meh, this is probably not the proof I was looking for
I saw some functionals so I figured it'd be the right one but maybe not
I am opening it up. If it relies on this lemma, then probably it's not a variational proof, but the one I read.
Yeah, this is the proof I know.
27
Q: Why is Fourier analysis so handy for proving the isoperimetric inequality?

Steven GubkinI have just completed an introductory course on analysis, and have been looking over my notes for the year. For me, although it was certainly not the most powerful or important theorem which we covered, the most striking application was the Fourier analytic proof of the isoperimetric inequality....

I don't see a variational proof there.
I think this contains it
section 14.10
Or at least a variation (ha-ha) of the problem.
12:16
Thanks.
12:53
@MaryStar Hi! I haven't yet studied stuff like that so I'm not sure if that's true. Why have you suggested that the closed unit sphere must be homeomorphic to an open subset of $\Bbb{R}^2$?
13:06
I thought that this should stand from the definition of a surface, that there should be an open map... But I am not sure if that's true... @Khallil
Isn't $[0,1]\times[0,1]$ a surface, @MaryStar?
Can this theorem from Titchmarsh be made into an effective lower bound for gaps between zeta zeros:
http://mathoverflow.net/a/226013/25104
?
13:23
Or does it only give an upper bound?
13:38
can anyone tell me how to write commutative diagram in mathstckexchange. I tried to use some latex code, but it is not working over here.
@SuperstarMonica any shining news
@Idle001 hehe, just working on my stuff. :-)
Hey all!
How can I see "LaTeX Math" here?
13:53
Nice proof
2
Q: Function on $[a,b]$ that satisifies a Hölder condition of order $\alpha > 1 $ is constant

elaRoscaI want to show that if a function $f:[a,b]\rightarrow \mathbb R$ satisfies a Hölder condition of order $\alpha > 1 $ then it is constant. The way I think of it is as follows: $$|f(x) - f(y)| < K|x-y|^\alpha$$ $$\frac{|f(x) - f(y)|} {|x-y]} < K|x-y|^{\alpha -1}$$ $$\lim_{y\rightarrow x} \frac...

(btw) I'm in the Poincare-Bertrand theorem stuff for one of my integrals.
14:33
does someone have an idea how to calculate (or narrow) the partial factorials ?
@StanShunpike Define the random variable $X = N(0, 4) - N(0,2)$. Intuitively speaking, do you see how this is equal to $N(2, 4)$? Now $N(2, 4) \sim \text{Poisson}(2\lambda)$, so your problem is equivalent to finding $$\mathbb{P}\left(\{N(2, 4) = 0\}\right)\text{.}$$
14:51
Hey @robjohn
Are you familiar with dynamic programming?
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