12:00 AM
@JasperLoy I am going to die from this cold
It has been a week

@Alizter Just drink more water and get more rest.

@JasperLoy I have been. My grandma was burning alcohol on my back to get rid of bad spirits as well.

@Alizter What belief is that?

@JasperLoy I think village rumours. I have no idea to be honest

@JasperLoy Grandma belief

12:06 AM
@user130018 Will you be spending Christmas alone?

@JasperLoy I will probably stay at the church, so no. There will be people there

@user130018 Are you Christian?

@JasperLoy No

Heh. I got a boat

@N3buchadnezzar What will you do with a boat

12:14 AM
@user130018 Wear my boat as an hat, what else?

@user130018 ^^
@JasperLoy heya

@N3buchadnezzar Hi! I am very sad. I hope I find the way soon, out of this darkness.

@JasperLoy you don't have the boat hat?

@N3buchadnezzar Nope. Maybe I will get it later on. I am not logged into math, lol.

12:20 AM
@JasperLoy Lol
I am depressed aswell

I am going to sleep. I hope the bodhisattvas will come to me in my dreams and teach me how to live the rest of this life. Good night!

Hello!!! How can I show the following identity of the cyclotomic polynomials??
$$\Phi_{pn}(x)=\Phi_n(x^p)/\Phi_n(x), \text{ where } (p,n)=1$$

12:41 AM
@MaryStar Recall that $x^n-1=\prod_{k\mid n}\Phi_k(x)$. Use induction.

1:25 AM
evening

If the sequence ${a_n}$ converges to a limit $L$, why is the following true? $$\lim_{n \to \infty} \frac{1}{n} (a_1 + a_2 + ... + a_n) = L$$

@Behaviour Should I delete that meta answer?

Maybe, maybe not. I just added a comment so people won't be following the link to nowhere. But the fact that such a thing was once proposed contains information.

1:43 AM
@MikeMiller I got the boat^^ As well as answered a question
Today was a good day

I won't edit it, as it needlessly bumps the question, and your comment contains all the information I would add.
I've been reading Meta.SE more since the Bash started, and now those new profiles are really starting to grate. I hope they don't intend to take them network-wide.

That's exactly what they will do. :(
My plan: as soon as the new design rolls out, I write an extension to make my browser open the Activity tab (whatever it will be) by default. So I'll never even see the new vanity page.

Make sure to make it publicly available.

Sure.

I'm still wondering what this question was trying to ask. He can't be asking about square-integrable functions, because there aren't good measures on infinite-dimensional Hilbert spaces, so I guess $L^1(H)$ means "the space of sequences $(x_i) \subest H$ whose sequence of partial sums converge", which does not seem like a very natural space.
(Nor do I understand how $x_i \otimes y_i$ is in it, or what that should mean.)
Update: as of two minutes ago Martin Aregami gave a dictionary. Whoops.

1:56 AM
I stand by "unclear what you're asking", regardless of the definitions. There is no question there.

The question desired is obvious ("How do I show this?"); the lack of clarity for me was knowing what was meant by the symbols.
Whether it should remain open in general is unrelated, but once the definitions are inserted, I do not think it's unclear what he's asking. Maybe one could throw in a word or two and a question mark while they're at it.

2:17 AM
@Behaviour What can I do to prevent deletion(by vote) of questions that I've answered before. Any tips?

@MikeMiller I follow the Dear Leader's interpretation of the closure reason: Unclear what you know == Unclear what you're asking

I was a bit worried that would be an Atwood answer. I don't entirely disagree (which is why I did not vote to reopen). But if people are going to subject themselves to a question it might as well be readable.

2:43 AM
in Tavern on the Meta on Meta Stack Exchange Chat, Nov 19 at 20:03, by Anna Lear
Deletions will continue until morale improves.

@Behaviour oh my gosh. did you realize that's this person??

@Behaviour I've since forgotten. Can you write down (or link to where it's written down) how community-user deletions work?

@MikeMiller There's a link in Community User's profile
Whoa, Community has the Warm Welcome hat!

What a nice bloke!

Despite all those deletions.

2:52 AM
It's tough love.

3:46 AM
I'm having some problems understanding a complex generating function
2

I was given a snippet and can't seem to parse it myself, what's the name of this format and is there a tool that will render it like latex or mathML like this site does? Sum_{n,k} T(n,k) x^2/n! y^k = 1+ln(Sum((4+y)^binomial(n, 2)*x^n/n!, n=0..infinity))

I can't seem to understand how it works

4:11 AM
If $M$ is a module and $N, P$ are submodules then $(N+P)/N = P/N$ correct?

hi
what is the "primary phase"?

4:50 AM
Could I interest someone in solving a definite integral involving legendre polynomials ? Specifically I need to solve $\int_{-1}^1 x^p (1-x^2)^{\frac{d-3}{2}} P_n^d(x) dx$
Sorry, how do I format latex so that it shows up nicely ?

Thanks
In case someone is interested in why the above integral is important, it basically arises when you are trying to compute the feature map of the $(x \dot y)^p$ which is a dot product kernel. Once you know the feature map you can approximate it and perhaps use multipole type approximation for fast test time performance. So basically it can be used for summing up n numbers in < O(n) time

5:15 AM
Tsk tsk, @Behaviour - didn't notice that this was a dupe?

5:27 AM
Is there a mathematician named Reimann? I know a Riemann, there are 64 posts with incorrect spelling.

This reminds me: I was recently reading about the Stieltjes integral in Rudin, but it came with no nice geometric interpretation or even much motivation. Why do we care about it?

@MikeMiller Not a dupe. Double post by the same OP. The logic is different.

How's a douple post not an exact duplicate?

Some people will go for closing as a dupe, which is not wrong.
But I prefer closing for whatever reason the first one was closed. So that it's more roomba-able.
The unintentional duplicates are considered to be mostly harmless, and occasionally useful. As signposts for users who search using the words not present in the original, but present in the duplicate.

Gonna need to explain that turn of the phrase. (I know what a roomba is, but not your use of it here.)

5:34 AM
Intentional double posts, which are invariably worthless to begin with, do not carry this benefit.
Roomba = informal name of auto-deletion scripts. If you read the description, you saw that duplicates are excluded from the closed question deletion criteria.
@HatMan I personally know a mathematician with the last name Reimann. But the questions are not about his work. Yes, the spelling is wrong.

@Behaviour I corrected a few of them to earn "Time Lord".
Any ideas on Eureka?

It's too late to earn Eureka, most likely.

@MikeMiller Why do you think so?

Because I know how one obtains it, and it seems to be a time-sensitive thing.

@MikeMiller How does one obtain it?

5:41 AM
Guess (independently) how to obtain a secret hat.
Because the methods of obtaining the secret hats are now well-known and fairly public, it would be hard to claim an independent guess.

Hey there @Bungo

Hi @KajHansen

@MikeMiller I read that the hat is awarded manually. How did you get it?

I read somewhere that the first 7 users to guess the logic of a secret hat get Eureka. The existence of the Meta.SE thread, where all the secrets spill out, threw a monkey wrench into the process. I don't think such a thread existed last year.
@HatMan Someone from SE ran a search over chat transcripts, network wide, looking for the names of the secret hats. Picked the early messages that contained an explanation of those hats. Gave Eureka to those users.

I always get tons of upvotes for the simpler questions and so few for the harder ones :(

5:44 AM
@Behaviour That sounds reasonable.

I hope I'm not just being obtuse about tetori's answer to this question: math.stackexchange.com/questions/1072786/…

@Bungo, you might be being obtuse :P Certainly, $\epsilon = 1$ works.
That is, for all $x \in [0, 1]$, $(x-1, x+1) \subset \mathbb{R}$.
Oh wait, I might be the obtuse one here.

I think after his edits, the argument is OK if he proves that $f$ is continuous, but that's the crux of the argument.

This is intuitive to me. I find that when I have an intuitive feel for something, a decent proof is just around the corner.

6:17 AM
OK, here's my answer (after a sushi dinner with three beers, so hopefully not too incoherent).
0

Here is an argument using open covers. For each $x \in K$ we can find some open ball $B_x$ of positive radius, centered at $x$ and contained in $U$. Let $C_x$ be the open ball centered at $x$ with half the radius of $B_x$. Then $\{C_x : x \in K\}$ is an open cover of $K$, so there is a finite su...

3 hours later…
9:19 AM
Rikudō Sennin, @r9m!
Great avatar!

@KhallilBenyattou :-)

Hey, @Venus. How are you today?

Thanks @r9m! I'm a big fan of it myself :D

If someone else was wondering how Community user decides which hat to wear, here is the answer: meta.stackexchange.com/questions/159273/…
2

9:23 AM
@KajHansen hehe ! :)

Sage of the integral paths, @r9m. ^_^

@Huy You first

@Venus: Okay. Woke up rather early, been tidying my flat so far because I have friends coming over tomorrow evening. I'll have to go to my school at lunchtime to copy a lot of old exams. How about you?

@KhallilBenyattou I'd rather walk my 6 paths away from that path =P (we know who wanders those lanes)

@MartinSleziak I wanna ask something. How is the number of stats profile views in our profile counted? Is it counted by the number of users here view our profile or the number of our profile has been seen?

9:28 AM
@Venus I am not sure about that. I remember that I read on meta that your own views are not coutned.

Indeed. If I visit Venus' page 10 times in one day, is that +10 on that stat? Or does it count unique visitors?

@Venus number of times its been visited ! (I tested that on @anon long time ago)

@Huy I wake up at 12 and still in the bed until 3 pm

It seems a wee bit technical for me.

@Venus: Why do you wake up so late?

9:31 AM
Okay, let's make a test. Can you visit my profile page now?
@Huy Because I slept so late :D

@Venus: I see. Did you see my posts yesterday? :3

I visited your profile. But due to caching, you should not expect the numbers to change immediately.

OK, Martin. Who's else?
@Huy What post?

@Venus: Mike posted an interesting question: math.stackexchange.com/questions/1072459/…
@Venus: Maybe you'll like the answers because you haven't studied (?) linear algebra yet.

@Huy OK, I'll read it later. Right now, I wanna stay away from difficult subject since the final exam is over :D

9:34 AM
@Venus: Linear algebra is the simplest subject in mathematics, imo. But sure, have a look at it whenever you feel like it. =)

My number stat changes by 2. Who else visit my profile other than Martin?

I did ..

@r9m Have you ever visited my profile before?

@Huy :P lol you think I'm flirting with her ? :-)

9:37 AM
@r9m: You're a male and she's a female, clearly the answer is yes.

@Venus ya .. a couple of times !

Please guys, be focus on the topic. Don't be like Ted
@r9m So, it's counted by number of views not by unique users

@MikeMiller: Did you see, BillD is back.

@Venus I guess yes ! I visit robjohn's and DanielFischer's profile a lot of time everyday (digging for answers :P) .. apparently refreshing or clicking on the tabs (answers,reputation, etc) the page while I'm on it does not increase the profile view count !

@r9m Maybe because the stat increases at one time you visit the profile page
@Huy I see this guy have arguments below Daniel's answer

9:46 AM
@Venus: Yes.

Anyone familiar with algebraic topology here?

@Huy Why he seems so upset?

@Venus: It seems the two had an argument some time ago.

I have also seen Andre upset & I don't wanna him leave this site
@Huy In my opinion, he has a good point about the issue

@Venus: Ok. I don't have an opinion about it just yet.

9:50 AM
Handling this sensitive should be done by consensus, not self action by a mod
Well, that's politics. People tend to be Machiavellians

@Venus: I have to get ready for lunch. See you later.

@Huy Bubye

@Venus Hi!

@Integrator Yo!

@Venus What's up!
@Venus By the way that view count method is kind of complicated.

9:59 AM
@Integrator Always good although today a bit tired because of sleep deprivation
@Integrator Do you have a meta link discussing that subject?

@Venus Wait!
42

This is related to the 'number of times your profile is visited by others'. How exactly does it work? For example, in my profile page, profile view count is 171.

@Venus There you go!

@Integrator Thanks

@Venus Don't mention it :)

easy answers get more upvote here. blergh.

@BalarkaSen What do you mean by easy?
@Venus See this

10:07 AM
well i have posted some more or less lhf-level answers and a big carefully written nontrivial survey-type answer. the former gets 5-7 upvotes while the latter only got 2.

@BalarkaSen I think people prefer simplicity.

simple answers might or might not be possible, depending on the question

Everything depends on the question.

@BalarkaSen If someone manages to answer easy but obvious problem within first few minutes then he might get upvotes.

@Integrator I don't see Bill there

10:13 AM
@Venus Oh sorry wrong page!
@Venus But he does not have any moderator badge.

This guy is funny
@Integrator Seriously?

@Venus Anna should've added because my mom would be so proud of me

sigh what kids will do to please their parents...

@Integrator And I am an Asian :D

@Venus I will vote for @Anastasiya-Romanova秀 If she uploads her photos again!

10:21 AM
@skullpatrol Idk that, maybe A+ mark.
@Integrator Why only for pictures you vote for her?

@Venus She's cute!

It is good for the parents @Venus but usually not so good for the child :(

@Venus I haven't seen you, yet ;)

@Integrator Now, I know why he leaves this site

10:25 AM
oh wow
hodge theory is galois theory of C/R
man.

@skullpatrol Asian parents are tigers, mostly :D
@Integrator You'll see me if you vote for Jack :D

@Venus Jack! Okay! I'd vote for anyone if I get to see you ;)

Are there any pdfs/books that I can read that will teach me about the symmetry of integrals?

Yes they are @Venus but the added pressure makes "paper tigers" of some of their children.

@Integrator The vote for him must be 1st choice :P

10:28 AM
Or any kid.

@Venus Okay! I'll send you screenshot after voting!

@skullpatrol But if they don't act like tigers, we won't see user like Anna

True. @Venus

39

There has been a lot of inquiry about recent events. This post is meant to clear that up and avoid speculation. In particular, I am posting this as a follow-up to a comment I had made previously. This is also a logical follow-up content in the following: Goodbye, Bill D. Should the old "l...

@Integrator Provided he gets elected. Haha.

10:30 AM
@Venus That's difficult :D

All I am saying @Venus is the will power to succeed must come from within, not just because you want to make someone else proud of you :-)

@skullpatrol But sometimes we need an external force & I think that parents' role here.
But that's purely my opinion, because you know :D

@DanielFischer Why do 10k users delete questions?

But not too much force. @Venus
And, of course, not too little :P

@Integrator Because they judge that the site would be better off with that question removed. Many people believe that having too many bad questions around invites further bad questions.

10:40 AM

@skullpatrol It looks like part of Asian culture, see Kyoiku mama
I have also heard lots of old Chinese stories about parenting & explaining why most of Asian parents like so

@Venus Hey. can you and Integrator help me? I just had an exam, and got an integral I was not able to solve

:O you? @Chris'ssis^

@N3buchadnezzar Are you sure needing my help?

$$f(x) = \int_0^\infty \frac{t e^{-t}}{(x+t^2)^2}\,\mathrm{d}t$$

10:45 AM
@Integrator They must be included in the judgment. A correct but trivial answer - say the correct evaluation of a bog-standard integral - is in many (including me) people's view not valuable enough to keep a really bad question. Something that makes the answer more than trivial, a good explanation, a neat unusual way to compute something, for example, is worth keeping.

Probably I just stared at it for too long

@N3buchadnezzar Integrating w.r.t. what? Is it $dt$?

@Venus Yeah. Pretty tough to get that integral on an exam :p

@Venus Do you really need to know that ?
@Venus It's $f(x)$!
@DanielFischer I'll look into that once I reach 10k

I think I found a closed expression during exam. But not sure if it was correct

10:50 AM
@Integrator Good. We need more users at least looking at that. And by your efforts so far, you could also save a few by editing them into shape, you're good at that.

@N3buchadnezzar What was that? $$e^x (x+1) \Gamma (0,x)-1$$

$f(x) = \frac{1}{2x} - \sum_{n=0}^\infty (-1)^k\frac{\Gamma(2n+1)}{x^{k+1}}$
@DanielFischer what grinds my gears is that people answer obvious duplicates instead of marking them as such.

@N3buchadnezzar It's often hard to search for duplicates.

@DanielFischer Does it mean that I can prevent deletion of questions by editing questions?

@N3buchadnezzar Indeed. One mitigating circumstance could be that searching for the duplicate is not so easy. But it's not that difficult that all the duplicates need to be re-answered.

10:53 AM
@N3buchadnezzar How did you get this closed form?

@Integrator Yes. If the question is in an acceptable shape, there is little reason to get rid of it.

@Venus Magic (integration by parts) but the convergence rate is slow

@Integrator But editing bad questions into shape can be a lot of work.

@DanielFischer Not for me!

You could do what professor Shifrin does when a student asks a bad question in his class and that is he edits the question into a good question that he can answer :P

10:58 AM
@Integrator Sure. After a while, I think it would even be good to change hint answers to more complete answers (not necessarily totally complete, leaving a few standard steps to the reader is usually fine, as long as the road is clearly laid out), but one does not always remember.

@DanielFischer Any idea?

Apparently accepting your own answer to your own question and not getting upvotes for more than 12 hours does not fetch the Naruto Hat :(

@r9m Need help? :)

@Venus I'd do anything for a Naruto hat :D Yes !
@skullpatrol this I felt stoopid accepting my own answer ! -_-

11:08 AM
@r9m Provide me an easy question that fit for this site. I'll post that question and then you give an answer to that question but your answer must be very simple that doesn't make users here amazed

Have you seen this @Venus?

@skullpatrol Not yet, I'll watch it later
@N3buchadnezzar This question turns out to be so hard for me

You're the Sage of the Six Paths!
Why'd you need a Naruto hat, @r9m?
You were the first human born with chakra!!! ^_^

@Venus hmm .. I thought of that (I was actually planning to ask my roomie to do me that favor .. but he'd die before he accepts my answer =P .. he never votes my answers for the same reason) .. in the end I couldn't come up with any question that fits the profile :-(

Hi @KhallilBenyattou

11:12 AM
Hey, @skull! How are you doing today?

@KhallilBenyattou $I \in$ Crazy Naruto Fan

Fine thanks @KhallilBenyattou how are you?

wow ! I was upvoted :-) Thanks !

np pal

@skullpatrol :D

11:15 AM
Same old, same old, @skull. ^_^
The new episode is out today, @r9m!

@KhallilBenyattou ya man ! In a couple of hours or so .. :D

@KhallilBenyattou Oh God !! BBL then :D

Same!!

Wow. Deligne did a double PhD as reference says.

11:17 AM
@N3buchadnezzar About the $\frac{te^{-t}}{(x+t^2)^2}$ integral? Not immediately. And I'm going away for a while now, so I don't have time to look into it at the moment.

Weirdo.

I very recently started Naruto because the manga ended, so the anime has to be ending soon. I'm impressed thus far.

@DanielFischer I did not mean to ping you, sorry about the inconveniece. Good luck in the election =)

Welcome to the dark side, @Fargle. ^_^

@KhallilBenyattou Haha, believe it.

11:19 AM
@Fargle Meh. Naruto is good Shippuden is poop

How does one even do a double PhD, @Balarka?

haha dunno

@N3buchadnezzar Haven't finished original yet, so I can't pass judgment.

Wait is that a postdoctorate?

I've been meaning to get into more anime a lot recently. Any other suggestions besides the obvious? (i.e. Naruto, One Piece, Bleach, DBZ, Cowboy Bebop, Yu Yu Hakusho, etc.)

11:21 AM
Inazuma Eleven @Fargle
It was a real good one.

Don't listen to Balarka, @Fargle.

throws table at @Khallil

Inazuma Eleven suuuucks.

aaaaah who do I listen to

11:22 AM
@Fargle The less you know, the more judgement you can pass. Have you not learned anything from religion or politics?

Fullmetal Alchemist (Original and Brotherhood), Death Note, Code Geass and ZOIDS are awesome, @Fargle.

FMA is my shiz. Death Note and Code Geass I should look into.

Is there something about Gurren Lagann that I just don't get, or is it really just as batshit insane as it seems to be? Every time I try to pick it up, it just tries its hardest to make absolutely no sense.

What was Death Note about @Khallil?

A Death Note!

lol
that leaves me completely unsatisfied

11:24 AM
Watch the anime!
(Subbed, not dubbed.)
^_^

nah

See, I'm willing to give Inazuma a chance though, because, I mean, for Pete's sake, I still think DBZ is a good anime.

DBZ is awesome

Death Note > DBZ

DBZ > every other anime in the world

11:25 AM
It IS awesome. But I don't know if it's good.

bashes @Khallil

19 hours ago, by Khallil Benyattou
Inazuma Eleven < Death Note, Fullmetal Alchemist (Original or Brotherhood), Code Geass, ZOIDS and Naruto to name a few.

@Fargle Dragon Ball (not Z) is better than DBZ, actually.

Oh, I know. I love the original, but I'm less familiar with the material.

materialises a kamehameha in one hand and projects it at @Balarka

11:26 AM
garlic guns at @Khallil

directs the garlic gun to his stir fry to add flavour

LEL

My real question is "Why didn't Piccolo just turn giant when they fought Raditz? Then Goku wouldn't have had to die."

Piccolo wasn't yet a supernamek then

But he turned giant when he fought Goku at the Budokai tournament five years before

11:27 AM
that was not a supernamek
that was a fake

or however many years passed between DB and DBZ

a fake supernamek, similar to a fake supersayian goku turned when he fought lord slug
and in any case he wanted goku to die

Well, yeah, that is certainly true.

actually i always thought piccolo was never a supernamek

I didn't think you had to be a SN to use the giant form.
Well, I mean, he absorbed Nail, and then fused with Kami, so...

11:29 AM
yes then he became a supernamek. i think he became something like a supernamek 2 or something
for example a supersayian 3 doesn't have to have big muscles.

I love the part right after he fuses with Kami because he's the strongest known character for like three minutes

i always wondered if broly and goku were distantly related
i guess they were.

...maybe? I don't quite remember.

you haven't seen the movies?

Not most of them.

11:32 AM
cell saga was the best part of DBZ

I've seen the first Broly one, Fusion Reborn, both Cooler ones, the Tree of Might...
Absolutely.
Cell saga > Frieza saga > Buu saga

right
no you missed the android saga somewhere

That's part of the Cell saga IMO
I divide them into 3-season clusters

ah, ok

Like, Buu starts with Great Saiyaman (-_____-)

11:34 AM
heh
animes can be good but... nothing beats marvel.

But yeah, the whole fight between Perfect Cell and Gohan was awesome, from the goading to the transformation to the Kamehameha battle.
And also Goku dying somewhere in there.

@Fargle i felt that goku was ss2 from the beginning.

I disagree--but my reason is about to cement me as the nerdiest person of all time.

ok?

When Goku and Vegeta fight after Vegeta allows himself to become Majin, they're both SSJ2.

11:37 AM
so?

There's a clear hair difference between the way Goku is drawn here and the way he's drawn as an SSJ1.
As well, at no point before this is Goku ever shown with lightning as part of his aura, and this is the defining characteristic of an SSJ2 aura

oh no i mean goku knew how to become an ss2, but he didn't do it since he wanted gohan to fight cell

OH
YES

sure there is a difference between SS2 and SS1
a big difference

I misinterpreted what you meant. But totally. He did the exact same crap in Buu saga--he could have totally creamed fat Buu when he was SSJ3 but chose not to because he wanted Gohan, Goten, and Trunks to save the world, not him.

11:39 AM
yeah :P
but he didn't do that and unleashed kid Buu with whom the fight was even harder

Thaaaaaaaat's Goku for you. Makes the fight harder than it has to be, and then still wins.

heh

"Here you go, Cell, have a senzu bean so you can beat the tar out of my only child."

lol

....of course, in that case, Gohan won, not him, but still, damn, dude.
...this is a chatroom about math.

11:41 AM
yeesh i guess so
but it wasn't that long we just ate up a page.
ok i gotta go