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12:00 AM
I worry your example will not be closed
I didn't know the result about $H^1(T) \subset L^1(T)$ stated there, that's really cool
 
Ok I think I got it
Thanks a lot !
 
Sure sure, sorry I didn't see your question earlier
The deeper you get into Banach stuff the harder it gets for me and I thought it was something out of my league
so I did not read it
 
The supposition that there is no rational $r$ such that $x<r$ and $r<y$ is equivalent to "$ x \geq r$ and $ r \geq y$ for all $r$".
 
Nope, you've got quantifiers confused.
 
Wait. Do you start with $x<y$?
 
12:04 AM
he did
 
Maybe the second part should be linked with "or".
 
That's exactly it
Quantifiers was the wrong thing of me to say, sorry
You forgot to flip the and
 
Okay
 
Conjunction/disjunction ...
 
You should not expect a purely formal proof
Something special is happening here
 
12:05 AM
Let me rethink
 
$\Bbb Z \subset \Bbb R$ is not dense
so somewhere in your proof you need to say something special to $\Bbb Q$ that will not apply to $\Bbb Z$
 
It's time for me to sleep, thank you again
 
@MikeMiller ah right
 
See you around !
 
the standard trick for detecting a false proof
is that if you follow the argument, it proves a stronger theorem
 
12:06 AM
@Astyx gnight
 
@Leaky: You mean a false stronger theorem. :P
 
boo
 
So the fact that it's "or" means that we can't simply deduce $x\geq y$.
Which would be the contradiction if it'd.
 
if it had
no
I can't make sense of it
 
I mean
If we deduce that $x\geq y$ then we got a contradiction
 
12:10 AM
Damn, I'm losted.
We're trying to prove that there's a rational number between every two reals?
 
Me too. There's too much formality going on here.
Construct.
 
We started with $x<y$.
@TedShifrin yes.
 
Can we do it when $x$ and $y$ are rational?
 
@TedShifrin wow, great hint!
i was trying to think of how to say something useful
 
(This isn't my first rodeo, @MikeM.)
 
12:12 AM
I assume you have a complete argument in mind, which is probably the same as mine
 
@TedShifrin Just to make sure I have the right approach; #5.i should be done by splitting the inequalities into cases?
 
@CaptainAmerica: Categorically NO.
 
@TedShifrin Yes, taking $r$ simply the arithmetic mean of the two.
 
ok so I was reading Serre's representation
 
12:13 AM
Can someone tell me what's so special with conjugate Hölder exponents?
 
and then I was looking at Chapter 5 - Examples
it started with C_n the cyclic group of order n
I was like... hmm sure this is a basic example
 
@OskarTegby have you looked at the proof of holders inequality?
 
When they're real, the arithmetic mean of two doesn't have to be rational. So another way is needed.
 
OK, @Abdullah. If $y-x>1$, can you do it?
 
and then the next example is S^1 the circle and somehow it's linked to Fourier series
 
12:15 AM
@TedShifrin I was going to suggest using knowledge about the way Q sits inside R. But I guess your argument is the same more explicitly.
 
That means there is an integer between two. @TedShifrin
 
@MikeMiller: Yeah, but I don't understand why it's so important in $p$-harmonic analysis. If we have that two numbers $p$ and $q$ are conjugate Hölder exponents, then $u$ is $p$-harmonic, and $v$ is $q$-harmonic. It gives us that $\langle\nabla u,\nabla v\rangle=0$, but I don't see any intuitive reason why the exponents have to be Hölder conjugate. I can make the computation, sure, but other than that I don't know.
 
Can you see how to rescale that if $y-x>1/n$?
 
@OskarTegby Oh, I know nada about that.
 
(We defined an "integer part function", but i don't want to use it.)
 
12:16 AM
use it.
 
@TedShifrin Archimedian property
 
@publicstaticvoidmain lol, nostalgia (java is the first programming language I learnt)
 
Ok, let me advance a bit
 
@MikeMiller: Well, you basically have to dig the $p$-Laplacian to do that. I guess that I should ask my professor about it.
 
I'm told it's interesting, I am just an ignoramus.
 
12:17 AM
The $p$-Laplacian?
 
@LeakyNun cool, it's the first one I learned too.
 
yes, and (of course) its minimizers
 
Fourier theory is just the fact that L^2(G) = L^2(Pontryagin dual of G)
 
So you get an integer between $ny$ and $nx$, @Abdullah?
 
@LeakyNun irritating, but not wrong
 
12:18 AM
lol
 
Yeah! It has some remarkable properties. I really like Peter Lindqvist's notes on it.
 
Leaky is superior at irritating.
 
It's not very nice to say that people are irritating.
 
It's well known that I am a not nice person.
You can kick me out.
 
have you never tried sleeping while the wauter faucet is leaking droplets ? that's pretty irritating
2
 
12:20 AM
@TedShifrin ouch
 
LOL @Leaky
 
@OskarTegby I do not think Leaky is too hurt
 
Brutal.
 
howdy @Fargle
 
@mercio No, but I have tried to sleep while a baby was slapping me in the face.
 
12:20 AM
awww
 
Hey @Ted. That ping made me realize that, although I'm wearing headphones, they aren't plugged in.
 
lmfao
 
Yes, you are @Ted.
 
I have tried sleeping while the party of italians were playing a lourd mafia card game thing in the next room then I pretended to watch and be interested only to steal their deck of cards and hide it
 
@MikeMiller: No, but it's important to keep a friendly tone imho.
 
12:21 AM
LOL @mercio
 
@mercio lol
man this room is addictive
 
@OskarTegby I think it's ok between people who are well acquainted. Good fun.
 
but then they decided to sing EVEN MORE LOUDLY until I gave them the cards back
 
@Oskar: There is plenty of teasing that goes on in here. Leaky and I do not have a problem.
 
@OskarTegby I hadn't paid much attention to stuff in here, and somehow I thought you were taking linear algebra or something... so I was surprised to see p-Laplacians.
 
12:22 AM
Okay. I trust you on this.
 
Thanks!
 
@MikeMiller: I'm taking like seven classes this semester.
 
4 mins ago, by Leaky Nun
Fourier theory is just the fact that L^2(G) = L^2(Pontryagin dual of G)
@TedShifrin do you have a reference (of a proof)?
 
If it helps, and you are not aware: the dual space of $L^p(\Bbb R)$ is $L^q(\Bbb R)$. That's largely what Holder is telling you.
 
isn't quoting yourself a standard proof technique
 
12:23 AM
Why did you think that I was taking linear algebra?
 
Wow, I wrote that wrong.
 
@mercio lmao
 
With the assumption that we're done with $y-x>1$, we can say that there is a natural $n$ such that $y-x>\frac{1}{n}$. @TedShifrin That intuitively means that we're also done for $y-x>0$. Because $\frac{1}{n}$ can be sufficiently small.
 
@OskarTegby Bad memory, probably conflated your posts with someone next to you.
 
@MikeMiller is that directed to me?
 
12:24 AM
No, but rather the guy asking about Holder conjugate exponents p and q? :P
 
@MikeMiller: Yeah! I recently saw that in functional analysis. It still seems like magic to me.
 
@Abdullah: Right. So why did I specifically put $1/n$?
 
@MikeMiller wow that's way above
 
I was the one who asked about conjugate Hölder exponents. :P
 
@Leaky: I am not a Fourier expert at all. My standard reference is Körner's book, and I don't think he's that fancy.
 
12:24 AM
@TedShifrin maybe i should just go read Tate's thesis then
(nope)
 
Come on brain! I don't want to sleep. I want to do math.
 
@OskarTegby I think that it probably all comes back to Holder's inequality, and the point being that if you want to bash two things against each other and integrate, the best you can do is when the exponents are comnjugate.
That's all I can really offer.
I'm a 2-Laplacian guy.
 
Haha
 
@TedShifrin who is the Tate guy here?
 
But why is it in the dual space?
 
12:25 AM
what does that mean? it's the same Tate as everywhere else
 
I mean, who should I ask here if I have problems regarding Tate's thesis
 
@OskarTegby If $g \in L^q(\Bbb R)$, then the map $g^\vee: L^p(\Bbb R) \to \Bbb R$ is given by $g^\vee(f) = \int gf$. That this is continuous is Holder.
 
Does anybody here know that stuff? Mathein dabbles in it, I guess.
 
@TedShifrin Can I assume that $a<b$ such that $b-a$ is in $P$? Does that have to be explicitly stated?
 
So that the natural n cancels in the usage of archimedian property. That's a naive explanation, though @TedShifrin
 
12:26 AM
or just abstract fourier theory...
 
I contemplated reading it about 5ish years ago
 
@mercio and what happened?
 
I skimmed through it because i had to nentoe someone who wanted to read it - i basically forgot most things though
 
when I was learning class field theory
 
Isn't that just like Riesz?
 
12:27 AM
I guess in the end I didn't
 
I do roughly know what Tate's thesis is about
 
and abstract fourier theory?
 
@Abdullah: No. Multiply by $n$. What happens?
 
But you shoild check Poonen’s notes on tates thesis - theyre really readable
 
ok i'm mainly asking for a reference for L^2(G) = L^2(Pontryagin dual of G)
 
12:28 AM
@TedShifrin I think I already got that part.
 
@MikeMiller: Isn't that just like Riesz? I don't see how the exponents yield this. I guess that it's because it's non-trivial.
 
I saw the utilisation of archimedian prop, there.
 
@OskarTegby It's a rather formal statement, to be sure, but continuity means that $\|gf\|_{L^1} \leq C \|f\|_{L^p}$.
 
Riiight.
 
And that $C$ is the $q$-norm of $g$ in the statement of Holder.
Ultimately, it all comes back to that one inequality.
 
12:29 AM
@Abdullah: So what happens from what we've said?
 
Okay. I get it now!
Thanks, @MikeMiller.
We're using Riesz, right?
 
I don't remember what that is. The representation theorem?
That's for Hilbert spaces
 
Yeah
 
do we have $L^2(G \times H) \cong L^2(G) \otimes L^2(H)$? it seems reasonable
 
Isn't that what $g^\vee(f)=\int gf$ was?
What does $\vee$ mean here?
 
12:32 AM
Just some notation.
I wanted to distinguish between $g$ the function and $g$ the operator on $L^p$.
 
Oh! Okay.
 
I have to pay much less attention for a while now
 
Me too.
I'm going to bed.
 
Can I leave too? :D
 
@MatheinBoulomenos no! :O
you need a completed tensor product of some sort
 
12:34 AM
@Ted: Why couldn't you?
 
LOL, @Oskar. Good night!
 
Goodnight Ted.
 
Haha! What? Oh, whatever.
 
@CaptainAmerica: It's 4:35 here.
 
PM?
 
12:35 AM
@MikeMiller oh right
 
Yes, PM.
 
It's 7:35 pm where I am
 
Not too surprising, @CaptainAmerica.
 
Otherwise, it would have been pretty hardcore.
 
12:36 AM
It's 7:35 pm where I am.
 
Here, it's 01:36.
 
You're repeating yourself, apparently, @CaptainAmerica.
Did you finish that Spivak problem yet?
 
This sounds familiar.
 
It must have seemed like I was skipping school every day to you XD
 
deja vu
 
12:37 AM
Today's a holiday, of course ... not that our president would bother to honor it.
 
My internet is jacked up - all of these messages just popped up.
 
@MatheinBoulomenos There is I think a perfectly good, unique "tensor product of Hilbert spaces"
 
what holiday?
 
Veterans Day in the US ... to honor those who've served and those who've died ... in the military.
Not that I'm a person who notices such things usually.
 
Politics suck
 
12:38 AM
It's weird though I know a lot of places w/ no holiday today
 
@TedShifrin Not yet - as you can see I get easily distracted. Back to work.
 
growls
 
(The usual $V \otimes W$ in your sense has a natural inner product, so complete it)
gives you a symmetric monoidal structure etc satisfying the desired universal properties
whatever fancy words
 
It's hard to focus, my mom and sister are making beats and saying "Go EE." while my little brother stomps in the middle of the floor. They won't stop singing ;-;
 
12:42 AM
TeNsOr CaTeGoRy
 
question for you: is there a Hilbert algebra over $\Bbb C$ other than $\Bbb C^k$?
 
Go elsewhere, @CaptainAmerica.
Question for whom, @MikeM?
 
whoever
i think mathein
 
Oh.
 
but idc
 
12:43 AM
@TedShifrin You're a genius Ted.
 
@loch lol
@MikeMiller $\Bbb C^n$
 
rolls 12+$\pi/4$ eyes
 
for $n \ne k$
 
god you're awful
 
Does anyone have access to academic articles here? Looking for this paper: jpm.iijournals.com/content/45/1/141
 
12:44 AM
this is why we smack Leaky.
How is $\Bbb C^k$ an algebra, anyhow?
 
pointwise mult
 
ok so modular functions
 
this is a bad question on my part
 
I have no idea what this means.
 
there's a good question hiding here
 
12:45 AM
lol
 
how do you not know what pointwise multiplication of $(z_1, \cdots, z_k) \cdot (w_1, \cdots, w_k)$ means?
:P
<3
 
Oh. But that's totally basis-dependent.
 
confusing discussion. it's still an algebra
 
how to compute the modular function of a group?
 
I love algebra.
 
12:47 AM
yeah, not that algebra
 
I thought you left ages ago, @Oskar.
 
lol
 
I thought so too.
Then I started answering an email.
 
I'll come back in an hour or so and ask a good question
2
 
lol, "I thought so too"
 
12:48 AM
lol
 
man I can't focus in here
 
@MikeMiller: Me, every time I enter a store.
 
They're rapping now, I can hear them.
 
I don't like it when girls distract me from math. It sucks.
 
wat 0-0
@CaptainAmerica16 seriously, go to a different location
 
12:50 AM
Is this the sort of discussion I'm supposed to be squelching?
 
maybe
who knows
 
squelch them overlord
 
go squelch urself m8
 
howdy, Eric
 
@Mike im 100% noodle now
 
12:50 AM
OK, folks, let's try to stay sorta on track in here.
 
Hm... I don't understand anything.
 
hi @Ted
 
Zee
Girls distracting you from math? You crazy man...
 
Ted wanted us back on track, @Zee.
 
ok exact sequences $0 \to A \to B \to C \to 0$ are nice and all
but what is it with $\int_B f(b) \ \mathrm db = \int_C \int_A f(ca) \ \mathrm da \ \mathrm dc$
 
12:53 AM
@Zee: That is not the point here.
@Leaky: You have a fiber bundle and you're doing Fubini's Theorem.
 
Ok, I really am leaving to do the problem now. I had to do the beats for them.
 
What you wrote is not right unless it splits, but there's a way to make it right.
 
@Zee: Do you mean that I'm crazy by letting myself being distracted by them, or by wanting to not be distracted by them? Sorry for being off-topic. I'll stop this discussion after I've received the answer.
 
looks like this aint the right place to be rn
@Ted ill see ya, im off to spend the night on GH and probs
 
Thanks @TedShifrin, I'm a little bit tired now. I'll take a look at that tomorrow.
 
12:56 AM
Bye, @Eric. Keep me posted.
@Abdullah: It should be one line from what we've already said.
 
I've been pondering, though.
 
So you said $ny - nx > 1$ and so there's an integer between them. Write that down.
 
But, I want to think about it a little bit more.
@TedShifrin Yeah, that's true.
 
So what's the math sentence you write?
 
There is a $z \in \mathbb{Z}$ such that $nx<z<ny$.
 

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