Mathematics - 2012-08-25 (page 4 of 4)

Gustavo Bandeira

11:00 PM

@MeAndMath Eu nunca soube se aplicada é só aplicada e bacharel é pura e aplicada ou se bacharel é mais pura.

Peter Tamaroff

@t.b. I read that as "weak-ass" topology

MeAndMath

@GustavoBandeira é ,a "aplicação".

Jonas Teuwen

@t.b. Yes.

I should do something else, I am so unproductive for weeks! 8-).

I hate to be ill.

MeAndMath

@GustavoBandeira tem bacharel em matemática,bacharel em matemática aplicada,licenciatura em matemática,bacharelado em estatística e bacharelado em ciência da computação.

t.b.

@JonasTeuwen so what's the problem?

Jonas Teuwen

11:02 PM

There probably is none. The problem is Kopf.

Gustavo Bandeira

@MeAndMath Ah, tem bacharel em matemática e bacharel em matemática aplicada. Aqui só tem bach de matemática.

t.b.

Oh, I know that problem. Too well.

Jonas Teuwen

I spent five hours figuring out why $P(\mathbf N) = \mathbf R$. Apparently.

MeAndMath

@GustavoBandeira estranho

Jonas Teuwen

Ah, yes. Is it mathematicians thingie...?

Peter Tamaroff

11:03 PM

@JonasTeuwen Does that mean "powerset"?

Jonas Teuwen

I don't care if it does.

Gustavo Bandeira

@MeAndMath Ó aqui

Peter Tamaroff

@JonasTeuwen What do you mean by $P(\bf N)$???

Gustavo Bandeira

@MeAndMath No CCEN tem umas coisas a mais

Jonas Teuwen

Perhaps the Cech-Stone compactification? Or the ultrafilters?

Gustavo Bandeira

11:04 PM

Mas deve ser normal, isso aqui é Nordeste.

MeAndMath

dá uma olhada

Gustavo Bandeira

É completo demais. Tem até:
Matemática Aplicada - Bacharelado - Habilitação em Pornografia quântica.
Matemática Aplicada - Bacharelado - Habilitação em depilação estocástica de pelo de axila de primata.

Jonas Teuwen

Menschen geben mir Kopfschmerzen.

3

MeAndMath

@GustavoBandeira rsrsrsrsrs

Gustavo Bandeira

@MeAndMath Eu quero comparar os cursos.

Parece que num é muito diferente não.

MeAndMath

11:11 PM

é?

Gustavo Bandeira

Pelo que eu me lembro das matérias, parece não ser muito diferente.

Cê já teve topologia?

Peter Tamaroff

@GustavoBandeira LOL

MeAndMath

@GustavoBandeira estou estudando por minha conta agora...

Peter Tamaroff

@MeAndMath wait, how do you guys laugh?

Gustavo Bandeira

@PeterTamaroff LoL is acceptable.

MeAndMath

11:13 PM

@PeterTamaroff hahahah rrsrsrsrsrsr kkkkkkkk LOL sahushaushaushuash

Gustavo Bandeira

@MeAndMath huehuehuehue is also acceptable

Peter Tamaroff

@MeAndMath why "rsrsrsrsrsrs"?

Gustavo Bandeira

@PeterTamaroff rs = risos

risos = laughs

Peter Tamaroff

@GustavoBandeira look at that

Gustavo Bandeira

@MeAndMath Ah é? Idem, mas tu deve saber MUITO mais que eu.

@PeterTamaroff What?

MeAndMath

11:15 PM

@GustavoBandeira I don't know...

Gustavo Bandeira

@MeAndMath Cê sabe o que é um anel?

@MeAndMath É uma coisa que põe no dedo. =D

@MeAndMath Eu fui na faculdade falar com uns professores... O cara me fez essa pergunta: Me segurei pra não responder issso.

t.b.

@JonasTeuwen can you explain the notation?

Jonas Teuwen

@t.b. In terms of cardinalities.

Gustavo Bandeira

@MeAndMath Como foi? Tu fazia o curso e saiu?

t.b.

@JonasTeuwen And P(N) is what?

Jonas Teuwen

11:18 PM

Just $2^{\mathbf N}$.

Uh, wait.

No, I mean...

Or wait, I do mean.

That's the Cantor set right? Decimal expansions.

t.b.

yes.

ternary expansions, though.

Jonas Teuwen

So, for sets it is $\mathbf R$. I was trying to figure out that if $Y$ is a basis for a Hausdorff (compact?) topology if the space could maximally be $P(P(Y))$ in terms of cardinality. I think so, through filter bases, but... Kopf.

t.b.

I'm still at a complete loss about what you're trying to do.

Jonas Teuwen

Oh, working on some game theory. One moment, trying to recall. Need some fuel.

t.b.

@JonasTeuwen Do you mean this?

MeAndMath

11:22 PM

@GustavoBandeira eu sei ,sim.não ,eu não saí.

Peter Tamaroff

@JonasTeuwen Does the $P$ stand for powerset? (Why won't you tell me?)

Jonas Teuwen

I want to figure out what the additional conditions on $X$ other than compactness should be for the following to hold: The induced topology on $\mathcal M_+(X)$ by the vague topology is locally compact (yes), separable and metrizable.

@t.b. Ah, cool, The Ilya!

Gustavo Bandeira

@MeAndMath Tá fora por causa da greve?

Jonas Teuwen

Last week he was complaining he had was so unproductive, I asked a bit. Sounds like me 350 days per year. 8-).

MeAndMath

@GustavoBandeira não,não tem greve aqui não!

Gustavo Bandeira

11:24 PM

@MeAndMath Então o que o faz estudar por conta própria?

MeAndMath

só estou estudando sozinha mesmo.

Jonas Teuwen

I know the answer to his question.

MeAndMath

topologia não faz parte da grade e eu prefiro.

And because Peter is here to help!

Jonas Teuwen

We happen to have all kinds of crazy compactification guys here... van Mill, KP.

With his ultrafilters on $\mathbf N$.

@PeterTamaroff Sorry, it is the powerset. Sorry, it is not personal that I did not reply.

Peter Tamaroff

@MeAndMath I can't follow portuguese =D

MeAndMath

11:27 PM

@PeterTamaroff He was asking me why was I studying topology by myself and I told him because I wanted and because you can help me !

Peter Tamaroff

@MeAndMath Oh, yes. math.SE is here to help.

MeAndMath

@PeterTamaroff I'm happier because of SE!I'm learning more!

t.b.

@JonasTeuwen The map $x \mapsto \delta_x$ is a homeomorphism onto its image in quite some generality. So I'm pretty sure that it is necessary for $X$ to be metrizable and second countable.

Jonas Teuwen

Wait, what is a non-complete separable metric space? How does the separable set relate to the completion? It just is...?

Peter Tamaroff

@MeAndMath It is a cool page, yes.

Jonas Teuwen

11:28 PM

@t.b. Yes, I was afraid it was. (same argument)

The diracs always fuq things up.

And there is no good way to exclude them as they are Radon.

MeAndMath

@PeterTamaroff People help me!Answer my questions!We talk about math (mostly) all the time!AND I LOVE IT!

t.b.

@JonasTeuwen well, you could try to pick a measure on $X$ and look at only those measures which are absolutely continuous with respect to it.

Khromonkey

no one has been able to answer my question

Jonas Teuwen

@t.b. Yep, I will try that next.

Khromonkey

I need to know how to solve these types of questions

t.b.

11:30 PM

@JonasTeuwen so you'll get $L^1$ :)

Gustavo Bandeira

@Khromonkey What question?

Jonas Teuwen

Also I had stuff like $f \in L^p(X, \mu_i)$ for a collection of $\mu_i$ probability measures.

Khromonkey

the same one math.stackexchange.com/questions/186866/combinatoric-proof

Peter Tamaroff

@t.b. Is $$\left(\sum_{i=1}^n (x_i+y_i)^p\right)^{1/p}\leq \left(\sum_{i=1}^n x_i^p\right)^{1/p} + \left(\sum_{i=1}^n y_i^p \right)^{1/p}$$ hard to prove?

Jonas Teuwen

@t.b. Yeah, but that is also quite ugly...

My beloved Ornstein-Uhlenbeck. Is degenerate on $L^1$. That broke me.

MeAndMath

11:33 PM

@Khromonkey Is that $p$ something like probability?I still didn't understand tha $p$.

t.b.

@PeterTamaroff no, not really.

Jonas Teuwen

That's just Hölder.

Khromonkey

no, i just used it to say that all of the elements of a are $\leq 100$ and $\geq 1$

Jonas Teuwen

I like the integral inequality more as mixed norm inequality.

user19161

Pedro is trying to prove every theorem himself perhaps, which is good.

Jonas Teuwen

11:34 PM

At this harmonic analysis conference people had a hard time recalling the order. "But it is just a mixed norm inequality!".

Peter Tamaroff

@t.b. I only know how to prove Cauchy-Schwartz, and the case $p=2$ follows from that.

MeAndMath

@Khromonkey Ok.in a set of 16 distict elements.

Jonas Teuwen

@PeterTamaroff Well, try for $n = 2$ and $p$ not $2$.

Khromonkey

yes

user19161

@JonasTeuwen What, they don't know the holder or minkowski?

MeAndMath

11:35 PM

@Khromonkey Give me a sec.I will think.

Peter Tamaroff

@JonasTeuwen And then generalize?

Jonas Teuwen

@PeterTamaroff Then try to see what is the problem.

That is what all non-Grothendieck mathematicians do. If you cannot prove it add more conditions until you can.

Peter Tamaroff

@JonasTeuwen What do you mean?

user19161

if they can't remember holder or minkowski @jonas they have no business at a harmonic analysis conf

Jonas Teuwen

@JasperLoy No.

Damn it.

No energy for discussion.

Khromonkey

11:38 PM

I have to use all of those for my math olympiad

user19161

seriously, what do these conference people know these days?

Jonas Teuwen

The best in the world.

user19161

@JonasTeuwen time for bed then

t.b.

@PeterTamaroff It's Cauchy-SchwarZ (no t please). Why didn't Jasper correct that already?

Jonas Teuwen

It is mental energy, not tired.

@t.b. And also not Ornstein-Uhlbeck?

user19161

11:39 PM

time for coffee then or teae

t.b.

@JonasTeuwen you're the expert :)

Khromonkey

why dont you all try to solve my problem instead of fight?

user19161

@t.b. I was thinking which it was. I got confused with the distributions.

Peter Tamaroff

@t.b. Yes, I know.

Jonas Teuwen

@t.b. I wish. But apparently I am since the other experts are lacking a bit.

t.b.

11:40 PM

@PeterTamaroff then why don't you apply your knowledge?

Peter Tamaroff

@t.b. Just a slip of the mind =)

Jonas Teuwen

@JasperLoy I mean the mixed norm Minkowski.

For general measures.

t.b.

As Garling quipped: The most difficult thing about Cauchy-Schwarz is how to teach the students how to pronounce Cauchy and how to spell Schwarz.

Jonas Teuwen

Did you read his inequalities book (Garling)?

MeAndMath

@Khromonkey if you have 100 numbers and 16 that form a set ,it gives a possibility of 1345860629046814650 different sets.Is that it?

Jonas Teuwen

11:42 PM

Cauchy, that's not so hard is it?

t.b.

@JonasTeuwen Parts of it. It's nice.

Peter Tamaroff

@t.b. Hahhaa. I know how to pronounce Cauchy!

But you'd die if you hear how people generaly pronounce it here

user19161

My favourite proof is a one line proof that tb said was from the master Hardy himself.

Jonas Teuwen

@t.b. I think I took it from my advisor. I don't know how it got on my book shelf.

user19161

It just involves completing the square.

Jonas Teuwen

11:42 PM

Cauchy is just French - easy.

Schwarz have to say it like Goebel (in the speeches).

Wollt ihr...

Peter Tamaroff

@JonasTeuwen They generally sound like this Just press the speakerphone

MeAndMath

@PeterTamaroff O.o

Fortuon Paendrag

@PeterTamaroff What on earth?! The english one is comparably bad though..

Peter Tamaroff

@FortuonPaendrag What on **E**arth what?

Jonas Teuwen

The worst thing ever is that I heard somebody from Bordeaux pronounce "Hermite" like... an Australian.

Khromonkey

11:44 PM

@MeAndMath i think there are $\frac {100!}{(100-16!)(16!)}$ but how does that solve the question?

Jonas Teuwen

And... then a German was commenting on that.

MeAndMath

@Khromonkey It doesn't.I was just thinking.well,at least one of them satisfies the condition...

AFK.BBL

Peter Tamaroff

@t.b. Would it be too crazy raise the ineq to the power of $p$? and use the binomial theorem?

(Twice?)

t.b.

@JasperLoy I thought the one you like particularly is the original one by Cauchy: part 1 part 2.

Jonas Teuwen

How did people typeset integrals and so on preTeX?

@t.b. Jan van Mill's thesis was on a typewriter. I have seen it. In the introduction he does not say "thanks to my advisor van Douwen" but thanks to my coauthor...