@KannappanSampath I've not done anything since yesterday, sorry.

@MattN Never mind! There is the last thing, I don't still see a proof.

@tb It's nice to see you.

@KannappanSampath I'll look at it soon, I promise. I'm just not very productive at the moment.

@MattN Yes, nice to see you, too. But I can't really stay for long, however, I needed to get this slip off my chest

@MattN No issues. You can take your own time!

@SidharthIyer Of all talks at ISI, there was one talk accessible to everyone! :-)

@tb Ok. I don't count it as a slip.

@Kannappan: I took a brief look at your notes and thought I should link you to this and this. Those should contain some things that are worth knowing when writing math.

@KannappanSampath Really? Which one?

@SidharthIyer On Using Mathematics to Attain Secrecy.

@tb Thank You. I am reading them. But shall I ask you if you have some specifics?

@KannappanSampath LOL! Who was the speker?

*speaker

@SidharthIyer Palash Sarkar.

@SidharthIyer You can edit your message by pressing up key within a 2 minute time frame!

@tb I was actually slightly surprised about the song : )

@KannappanSampath Didn't know.

@SidharthIyer That's why I told you. :D

@KannappanSampath They're actually quite good, but I think reading those pieces (especially the first one) might improve them a bit. You do overuse words like "obvious", "trivial", "clear", and so on. Most of the time they are unnecessary

I think the "obvious inclusion" could also just be called the "inclusion".

yep.

@tb I see. I'll be happy one day if you point a few of them out!

@MattN Sure. I'll change them.

@tb But it's way too late to edit that comment now.

@KannappanSampath I wasn't talking about you there. : )

Is J S Milne for a joke? @tb

For some reason I find it very hard to get rid of the memory of this presentation I had to give on Friday. : /

@KannappanSampath He's quite serious about it :) Please don't get me wrong. I always recommend those two pieces to anyone starting out in mathematical exposition.

I wonder why this particular one's had such a big impact.

@KannappanSampath If you improve your writing your maths will improve with it, btw : )

@tb No, I like being criticised. This makes you better than those sugar coated misleading comments.

But, J S Milne: He says never write clearly. Funny! @tb

@MattN wait a few more days, it's barely been 24 hours since...

@KannappanSampath You need carbohydrates to keep you going though. And some vitamins in the form of vegetables...

@MattN : D

Salad for example... : )

@MattN Is this how you prepare salad?

@KannappanSampath I'm not Danish, so: no : D

I think I'll have to go for my dinner. I'll be back.

Byee!

@KannappanSampath Take Matt's advice seriously :)

And add some carrots to your salad.

I don't understand anything. I'll need to decipher them with the help of GCHQ, Britain! :-)

What's that carrots thing you have there, recently?

Oh, nothing... : )

Can someone tell me what do they mean concretely and what's up with Milne.

Milne ---Do the opposite, you'll sail through?

But for Matt--????

Wot? What about me?

@MattN Carbohydrate, Vitamin(Vegetables), Salad, Carrot?

Oh. That : D

@KannappanSampath You complained about sugar-coated comments. I was saying that you can't live off criticism only, you need some nice words as well sometimes.

@KannappanSampath basically, yes.

I then understood partly, but yet a confirmation.

I'll be back.

Okay, you guys, I should go, too. I'll be back on Monday or Tuesday.

@tb Have a nice weekend and see you then!

Looking forward : )

I missed the previous comment. (</3?)

No, never mind.

@MattN Same to you! Don't think too much about Friday...

Bye

Bye.

I was thinking of something just now and I wonder if anyone here can give me some insights. In spoken language we have many different ways to express a concept (ie, different languages: English, Mandarin, Arabic, Spanish, etc...). In software we have many ways to express a computation (ie, Assembly, LISP, Python, C++, etc...). However, as far as I understand it there's only one system of expression for mathematics. I'm not saying this is good or bad, but rather I'm curious why this is the case.

I was reading A. Zee's "Quantum Field Theory in a Nutshell", the first few pages already made my toes curl!

hello chatsnoozers!

@robjohn Hi.

@JonasTeuwen how is your day going?

@robjohn It is fine. How is yours?

I see I missed Matt. Evidently, he was not pleased with his lecture the other day.

@JonasTeuwen Pretty good, so far. I have answered some lhf, but I think they are good answers.

Why was he not pleased? Did not want to tell me.

Oh, let me check.

I just got back from a walk with Lilly.

The dog?

I did not get details about Matt's lecture. He was not talking to anyone about it.

Yes, Lilly is my dog.

She's cute.

@JonasTeuwen Thanks. She is 12, just earlier last week.

How long do you have her already?

We have had her almost 11 years.

Oh :-).

Hmm, my Lagrange multipliers are complex numbers...

Or at least, those are the only ones satisfying the equality.

Anyone here ever read Zero: The biography of a dangerous idea?

Nope. I don't read pulp fiction.

@JonasTeuwen what are you optimizing?

@robjohn An optical system!

Your eyes?

Are you building a pair of bionic eyes?

You should probably avoid X-ray vision, or any other radiation based vision. It seems likely to cause huge brain tumors.

Hi guys, help me please with the name of one mapping

The image f(rB) of any ball contains the ball alpha rB

I think it's something like "alpha-covering mapping"

Why does Mathematica with the units package not simplify things like Sqrt[Volt^2]?

Why does my electric field have Seconds as unit? Hmm...

@JonasTeuwen I tried to read it too and wasn't much impressed. The preface reads like the preface of a wonderful book, but in the actual body of the text it seems that Zee thinks his reader already has a proper textbook in quantum field theory and only needs to be given some fuzzy hints about how to understand a formalism that has been presented to him elsewhere ...

@HenningMakholm Well, I didn't get that far, I went through ch 1 & 2. Maybe it just proves that you're a mathematician 8-).

I'm actually quite surprised that one can get correct results from manipulating distributions as they do...

Well, chapters 1 and 2 are before it went really sour for me. My goal was just to find out what it is the physicists do, not to judge whether whatever it is has a mathematical right to work.

Unfortunately, Zee is all about "here is a nice way to think about the stuffy formalism in the textbook", but doesn't bother to tell the reader clearly what the formalism actually is; except incidentally on the fringes of his intuitive handwaving.

Hah, okay, my toes were already curling when I've read his "proof" of a distributional identity. I'll try to finish the book though, physicists seem to love it!

In chapter 7, he in fact says "I will let you discover Feynman diagrams on your own" -- and then proceeds to give 20 pages of hints and vague stage directions, but never actually provides enough information to allow the reader to verify whether the thing I figured out of my own from his hits is actually the same thing physicists speak of when they say Feynman diagrams!

And then the chapter is liberally peppered with "don't worry that you find this stuff hard and confusing -- it will clear up when you think a bit more about it". I wasn't much confused before he said that, but then perhaps that fact means that there was something I had missed, which ought to have confused me if only I had noticed? But he never explains to me what it is I should be confused about, so I can never know whether I have cleared the hurdle or just didn't reach it yet...

@HenningMakholm That sounds like a thumbs down.

Did you try Folland's book instead? @HenningMakholm

@JonasTeuwen Which Folland book? I find most of what I have read of his to be good.

Mmm... beer and beef, beef and beer. Yum.

@robjohn Quantum Field Theory a tourist guide for mathematicians, I believe.

@AsafKaragila puree the beef, and you have a liquid steak sandwich!

Put it all in the blender and make a beefr smoothie!

I made ground beef on a pan, somewhat like sloppy joe but a lot less "saucy". It's already half liquid.

I'm still hungry.

Hi all, before posting a question I wanted to see if anyone can help me here: how do I represent the number 255.0 (real, base 10) in base 5 in the form m * 5^e, where m is mantissa and e the exponent?

@JonasTeuwen No, but there was a MO thread where it was highly recommended, so it's on my reading list.

@HenningMakholm Maybe that's a better order, first read Folland, then you might have an idea how physicists work and then Zee. I have both, maybe I should try Folland first. But it has a lot of representation theory which scared me away a bit.

My hands smell like ginger.

Fresh ginger.

Hm, I actually dropped out of a representation theory course back in university. Mostly because I had trouble imagining what its applications could possibly be, and without that I was unable to distinguish beteen important key results and irrelevant-but-interesting by-the-ways. Perhaps a book that applies it is just what I need.

@AsafKaragila I'm sorry to hear that.

Hi

Is there any way to approximate functions outside of 0,2pi using fourier series?

Sure, expand it!

I have a function from -1 to 1, then I could simply use those limits when calculating the Fourier coefficients?

@N3buchadnezzar Better stretch it horizontally by a factor of pi first.

(Or compress the base functions to have periods of 2n rather than 2pi·n).

Mmm

If the $[0, 2\pi]$ would really be this important, you would have a very lousy theory, no?

If you can do it on $[0, 2\pi]$ you can do it on any bounded closed interval.

I think that m.SE is aware that I have to sit and prepare a presentation on the Whitehead problem. There were no questions I'd answer today!

Is my comment here confusing? The only convergence that the series has would be as a divergent series, but perhaps that is confusing for the OP.

@robjohn I like it 8-).

The OP was having trouble even seeing that it was $\sum_n2^n$, so I was worried about this just being too far off for them. I felt a bit impish, but I don't want to go beyond that :-)

Is it -1 in a more general sense than by appeal to 2-adics?

Looking at the power seies for $\dfrac{1}{1-2x}$ at $x=1$

Ah, yes.

Off to lunch. bbl

@robjohn Have a nice meal :-).

Should I have mentioned that talking to shelves suggests a psychotic breakdown?

@AsafKaragila Nothing a 'lil Haldol® can't solve.

What about a lot of Haldol?

The more the better!

I think I read somewhere that it's not really better.

Lies!

@Asaf This user has been like this all along. Just very arrogant!

I know.

And, How has the presentation for the Whitehead Problem been ?

Have you TeXed up your presentation?

I cannot decide.. :-)

@AsafKaragila What do you mean?

The problem itself is undecidable.

Now, the question seems to have a decisive answer, no?

Yes. Its answer is that it is undecidable.

scratches his head Do you mean that the presentation is neither complete nor incomplete?

That too.

: D

Shelah proved that there are models of ZFC in which the Whitehead Problem has a positive answer, and other models of ZFC in which the answer is negative.

I've cleaned my window. Now actual light comes through!

@AsafKaragila Live long Shelah.

He's pretty old, you know.

@JonasTeuwen What light? It's 23:15

@AsafKaragila Street lights.

:-)

Oh.

Anyway. I am going to clean the dishes and sleep. Very early morning tomorrow; very long day will follow it.

Tomorrow I'll stay in bed until 4PM.

@AsafKaragila Good night.

I am a bit disappointed to have a 0 rep day after a 245 rep day (+90 which went to the spill)..

@Asaf Good night!

Hope Matt will be around on Monday afternoon, so we could do some Analysis for exam.

@AsafKaragila Better that than two 180 rep days, I'd say.

Hi =)

Finally latex is done =)

They released LaTeX v3?

No, I am just finally managed to get it to do what I want.

@AsafKaragila My shelves beg to differ.

@HenningMakholm Well, indeed I am one day closer to the Epic badge, but still.

@AsafKaragila aren't we all :-p

@robjohn Well, no. Arturo is getting further from that badge. :-)

I also need like 3 votes in functional-analysis for the Generalist badge.

I noticed that the questions I have in some non-set theory tags are those which are about AC ;-)

@AsafKaragila We already got one of those. :-)

I told him we already got one

I don't have one :-(

Wait, is this the castle of Guy DeLombardo?

It's a quote from Monty Python and the Holy Grail.

I know. I recognized that, which is why I asked if this is the castle of Guy DeLombardo.

Ruiz' de lu la Ramper

According to one source at least

?

@AsafKaragila GUARD: This is the castle of Our Master Ruiz' de lu la Ramper

the spelling is in question.

French names are always confusing me.

another says: This is the castle of of my master, Guy de Loimbard.

Yeah, that's the one I remembered.

I have the script...

I recalled a play on the name Guy Lombardo.

In the script as it was before filming it was: This is the castle of of my master, Guy de Loimbard.

So the one transliterated from the film was wrong.

Hooray! My memory is not that bad!

Good game, just before hitting the hay I get a LHF and reap 50 rep (at time of writing).

@AsafKaragila I have two moderately LHF from this morning, and they have a couple of votes between them :-(

Well, I left a comment to one of your LHF that he should upvote and accept.

@AsafKaragila Thanks. we'll see if he listens :-)

Well, I just got another vote each :-)

whistles innocently

So... how 'bout them knacks?

@Asaf What about the new Post Doc, is he an Algebraist?

I'm not sure. He works with analysts, I think. You know, Banach spaces and operator theory.

I don't really know the post docs. Especially since there aren't many in set theory.

I see. I have heard about Banach spaces and Operator theory.

Anyway, this summer is a nice opportunity for me to work with Prof. D S Nagaraj who is an Algebraist. Hopefully, I'll get to know people like this!

(I am being supported by a fellowship :-))

@Asaf when is that lecture about Whitehead's Problem scheduled?

Monday.

I really want to finish these assignments already so I can get started on my thesis, and return to set theory research.

I'm bored and frustrated from all these homologies. >:(

Conjecture: people are more likely to upvote answers when the answerer is already capped for the day.

Yeah, it is possible. Also yesterday I had like two or three times that in a few minutes rush where unrelated answers were upvoted at once. This was post cap, so I wonder if the voter noticed at all.

@Henning Are you any good with alg. top.?

@AsafKaragila Not any better than the last time you asked me :-)

Oh. I already asked you? Drats.

@AsafKaragila Here.

Well... that just could have been anyone.

But really ... I think the world is out to ironically get me for saying earlier tonight that capping is better than not capping. I've had 25 upvotes thrown to the dogs since then.

That's like a whole other cap.

@HenningMakholm I wish I was one of those canine variety?!

Hey @Karagila, does this ping you?

exploring

No. It does not.

@KannappanSampath You had it going quite well until a couple of weeks ago. Did the semester start, or what?

@HenningMakholm Yes, exams were around then. Now, we have exams.

:/

I'm afraid I'm not really grasping the difference.

We are having exams now and I occasionally visit the site, and answer LHF.

I think he means that before the exams were "coming" but now they are here.

The topology of the exams is closed in the timeline. I think, would be the main point here.

@AsafKaragila Precisely. I was typing up an essay. Thanks for saving my work. :-)

Stupid alg. top. questions. Why won't you get solved already?!

@HenningMakholm Have you capped?

Oh, I see you have. +1 later!

@KannappanSampath Very much so.

: )

Hm. Actually I am only two votes from Generalist.

Already $4$ to the dogs!?!? @HenningMakholm

What dogs?