Mathematics - 2023-07-03

PNDas

03:49

Can anyone please help me with question 5 of www-users.cse.umn.edu/~garrett/Writtens_Archive/Real/…

What is $C^o$?

I guess vanishes at $-1,1$. How to do these type of questions?

one potato two potato

continuous function. I remember it uses Weierstrass approximation.

PNDas

I think that was a different question $\int f x^k=0$ for all k then $\int fg=0$

Okay I see what you are saying.

But in this www-users.cse.umn.edu/~garrett/Writtens_Archive/Real/…

They have $f(1/2)$.

one potato two potato

so?

use density argument or something

george

07:23

i bookmarked chat conversation but can't find UI to find the bookmark

george

08:07

ok never mind manually saved to pdf now, but weird I couldn't find that btn

Sonozaki

Can I prove that $a<x$ implies $\exists n\in\mathbb{N}\setminus\{0\}$ such that $a \le x+1/n$ as follow: assume that for each $n \in\mathbb{N}\setminus\{0\}$ we have $a \le x+1/n$, then given any $\epsilon>0$ if $n \ge \lceil1/\epsilon\rceil+1$ then $x+1/n<\epsilon$ and so we have $a<x+\epsilon$ for each $\epsilon>0$. This implies $a \le x$.

So, since the negation of $\exists n\in\mathbb{N}\setminus\{0\}$ implies the negation of $a<x$, the statement $a<x$ implies $\exists n\in\mathbb{N}\setminus\{0\}$ such that $a \le x+1/n$ holds.

I wrote the first message wrong, I will rephrase: assume that for each $n\in\mathbb{N} \setminus\{0\}$ we have $a>x+1/n$. Then, given any $\epsilon>0$ if $n \ge \lceil 1/\epsilon\rceil+1$ then $a>x+\epsilon$ for each $\epsilon>0$. This implies $a \ge x$, and this latter inequality is the negation of $a<x$.

Shaun

09:55

Hi :) I just thought I'd advertise a bounty:

1

Q: The torsion subgroup of a diagonalisable linear algebraic group $G$ with ${\rm char}(k)=p$ (alg. closed $k$) is dense in $G$

This is Exercise 3.2.10(5b) of Springer's, "Linear Algebraic Groups (Second Edition)". The Question: Let $p$ be the characteristic exponent of an algebraically closed field $k$. Let $G$ be a diagonalisable linear algebraic group over $k$ with character group $X$. Prove that the subgroup of eleme...

冥王 Hades

11:47

^When someone says Math is boring

user4539917

12:41

Mats Granvik

https://chat.stackexchange.com/transcript/message/63872730#63872730
Finding divisors of $n=2$ to $n=13$ as solutions to a knapsack problem.

These two knapsack problems find the divisors of 9 and 12 as two subsets of the solutions to a knapsack problem. I am too lazy to write a general program for the divisors of numbers 2 to 13. Beyond 13 I don't have enough computing power.

user4539917

$Mathematics$ Number theory

σκουλήκι

15:24

if i have two semi-groups $P_t,\bar{P}_t$ with generators $L,\bar{L}$ how is it that $\frac{d}{ds} P_{t-s}\bar{P}_{s}f= P_{t-s}(\bar{L}-L)\bar{P}_s f$ ?

is there a name for that formula?

PNDas

Today, I had my PhD Qualifying exam. It didn't go well. There are 6 questions and you have to 3 or 4 perfectly correct to pass. I skipped complex analysis as they also skipped the subject in the past two semesters due to time constraint or whatever. But they asked 3 questions from complex analysis.

Xander Henderson

@PNDas Sounds like you could be in trouble. :/

PNDas

I could do one as it was just evaluating an integral using Residue theorem.

Xander Henderson

Will you be given another chance?

Also, how many quals do you need to pass?

PNDas

Yes but the worst part is that the teacher who will check my answers is the person with whom I wanted to do my PhD.

Now I think it will leave a bad impression on her.

porridgemathematics

15:31

that's not necessarily true

Xander Henderson

Maybe. But not use crying over spilt milk. Also, I wouldn't make assumptions.

Though if you are hoping to work in analysis, and you f' up your analysis qual, you could be in trouble.

porridgemathematics

true

Xander Henderson

I only masters passed my topology qual, but I don't really care all that much about topology so... meh.

PNDas

After the exam I talked with her. I thought I should let her know that all the teachers skipped the complex analysis. But I thought that she will think I am making excuses.

Xander Henderson

Yeah, I wouldn't make excuses.

PNDas

15:32

So I didn't tell her anything.

porridgemathematics

that's probably for the best

Xander Henderson

Indeed.

PNDas

@XanderHenderson I want to work in PDE.

Xander Henderson

Also, it is possible that you did better than you thought.

@PNDas Well, having a strong background in analysis (particularly in funky anal) is helpful there. Complex analysis is likely less important, and if you are hoping to go in a more applied / numerical direction, you might not need all that much analysis, anyway.

See how your scores come out, then go talk to this person and see what they think.

porridgemathematics

I was about to say, the three lines lemma is important in PDE

but that's a really niche technical result

it is really used though, in interpolation theory

e.g. to prove Riesz-Thorin

and also interpolating sobolev spaces

Xander Henderson

15:35

@porridgemathematics Never heard of it.

PNDas

I am sad that I didn't remember the proof of this one: If f is bijective holomorphic map on D\{0} to D\{0} then f(z)=az, |a|=1.

I knew I have to apply Schwarz lemma but got stuck somewhere.

porridgemathematics

@XanderHenderson its niche. It is important though

Soumik Mukherjee

@PNDas Which institute?

Xander Henderson

@porridgemathematics I am sure that it is important in some niche, but if you are in that niche, you'll likely learn it.

Whether or not you are otherwise expert in complex anal.

PNDas

@SoumikMukherjee I don't want to tell it here now. As someone may know the prof and will tell her

Xander Henderson

15:37

I mean, my phd thesis uses a ton of complex analysis, but I never took a complex anal qual.

porridgemathematics

yeah definitely @XanderHenderson

PNDas

Also they asked math.stackexchange.com/questions/1462539/…

Soumik Mukherjee

@PNDas Np

Xander Henderson

(They dropped the requirement from four quals to three about two months before I was scheduled to take the complex qual. So I ended up not needing to take it. Yay.)

porridgemathematics

what were the three quals?

Soumik Mukherjee

15:38

What are these quals?

porridgemathematics

@SoumikMukherjee exams you take usually in your second year of a phd

PNDas

I couldn't do that question. I had no idea where to start. I tried to get a contradiction using Banach Steinhaus but didn't know how to proceed.

Xander Henderson

@porridgemathematics I took real anal, pdes, and topology.

I was going to take complex, and there was an algebra qual that I didn't want to touch with a 10 foot pole.

porridgemathematics

that's a good mix

PNDas

Let $f_n\to f$ a.e. and $\int_{B(0,1)}|f_n|^2dx<C$ for all n then Show that $f\in L^1(B(0,1))$ and $f_n\to f$ in L^1.

Xander Henderson

15:41

I think so. I also did all of this at the beginning of my second year (at the time, the expectation was that you would finish your quals by the end of year three; I killed them off as fast as I could).

PNDas

I could show that $f\in L^1$ using Fatou's lemma

For the second part, I heard that you need to use Vitalli convergence theorem which I don't know.

Xander Henderson

I am led to understand that the dropped the requirement from three to two after I left, and introduced an "applied mathematics" qual. This disappoints me. It should not be possible to get a PhD in mathematics without having taken a qualifying exam in either analysis or algebra. :/

porridgemathematics

@PNDas for the complex analysis one - you have a removable singularity at $0$, which can't map to the boundary of the disk, or else you violate $f$ being a bijection on D - 0 to D - 0, so its sent somewhere in D. It can't be sent to some point other than 0, because then you violate injectivity of f on D - 0 by the open mapping theorem

@PNDas so f is forced to map 0 to 0, which makes it a rotation

PNDas

Do they teach Vitali convergence theorem in Measure theory course?

Soumik Mukherjee

@porridgemathematics Are there any courseworks too, or only quals?

porridgemathematics

15:43

@SoumikMukherjee I didn't have courseworks, it could vary from uni to uni

@XanderHenderson oh wow, yeah I agree..

Soumik Mukherjee

ohh

Xander Henderson

@SoumikMukherjee Depends a lot on institution and country.

PNDas

@porridgemathematics What I did: I argued that $\lim_{z\to0}f(z)=0$ and there exists an extension g:D to D biholomorphic. Now I should argue that g is rotation. I applied Shwarz lemma to get $|g(z)|\leq|z|$ and $|g'(0)|\leq 1$. Then I said, $|g(z)|=1=|z|$ so g is a rotation.

Soumik Mukherjee

@XanderHenderson yes, here usually the first year of PhD is for course works.

Xander Henderson

In the US, a typical mathematics phd program will consist of maybe 2 years of general coursework (algebra, topology, analysis, maybe number theory or pde, etc), and maybe another year of more specialized coursework.

PNDas

15:47

Is that argument correct?

I meant they are $1$ on the boundary.

porridgemathematics

@PNDas all bijective holomorphic maps D -> D sending 0 to 0 are rotations, this indeed follows from Schwarz lemma, its actually just a restatement of Schwarz lemma

not sure what you mean by 1 on the boundary

Soumik Mukherjee

@XanderHenderson When did you find your topic of interest? In the first two years of PhD or before enrolling to a PhD?

PNDas

Schwarz lemma says if $|g(z)|=|z|$ for some z or $|g'(0)|=1$ then g is rotation.

So I had to show one of them. I guess Schwarz lemma needs $|g(z)|=|z|$ (for non zero z) in the open unit disc. I just said on the boundary, $|g(z)|=|z|=1$ so it is rotation.

I think that is the mistake.

porridgemathematics

you can use Schwarz lemma to derive the general form for an automorphism of D

Xander Henderson

@SoumikMukherjee I came into the phd program having finished masters elsewhere, with some hope of continuing in the same general direction. I had a research topic by the end of my second year (after passing my quals, before my oral).

Sourav Ghosh

15:54

0 is removable singularity.

porridgemathematics

they look like $a \frac{z - \zeta}{ \overline{\zeta} z - 1}$ where $|a| = 1$

Soumik Mukherjee

I just completed my M.Sc and got the feeling that I still don't know what topic I like the most.

porridgemathematics

so the ones fixing the origin are rotations

I guess its unfair to call that just Schwarz lemma

Sourav Ghosh

Extend f holomorphically on D

porridgemathematics

but you only need Schwarz lemma to prove that these are all the possible automorphisms

PNDas

15:55

And for that measure theory quetsion: I took $f_n\to f$ a.e so $|f_n-f|<M$ a.e. for some M. Let $\varepsilon>0$ then I used Egorov theorem . $\int_{B(0,1)} |f_n-f|=\int_{A_{\varepsilon}}|f_n-f|+\int_{A_{\varepsilon}^c}|f_n-f|<M\varepsilon+\int_{A_{\varepsilon}^c}|f_n-f|$ so $\lim \int_{B(0,1)} |f_n-f|\leq M\varepsilon$ for every epsilon so f_n converges to f in L^1.

porridgemathematics

here $\zeta \in \mathbb{D}$ of course

PNDas

How does it sound?

Sourav Ghosh

Apply maximum principal to show that extended holomorphic function must fix 0.

PNDas

@porridgemathematics So my argument was wrong?

@SouravGhosh Hmm I did that.

How does this measure theory question looks like?

porridgemathematics

@PNDas yeah, schwarz lemma needs $|g(z) | = |z|$ for some z in D, not on the boundary

ill take a look at your answer

you could have stopped at showing $f(0) = 0$, and then proved that automorphisms of $D$ fixing the origin are rotations

which would ultimately need Schwarz lemma

but I don't think what you wrote works unless Im misunderstanding

boundary behaviour isn't a factor in applying Schwarz lemma

one potato two potato

16:00

I like qual problems. They're usually well-refined problems.

PNDas

Hmm the problem was that I tried to do this question one day before the exam. And I somehow convinced myself with the wrong argument so I didn't look at the proof. But while writing the proof in the exam, I got to know the mistake.

Can you anyone please check my answer to that measure theory question:chat.stackexchange.com/transcript/message/63914196#63914196 , my answer: chat.stackexchange.com/transcript/message/63914273#63914273

porridgemathematics

@PNDas how did you get $|f_n - f| < M$ a.e. for some $M$ from $f_n $ -> $f$ a.e.?

PNDas

I meant after some large n

porridgemathematics

you can use Egorov to get that on a subset of B(0,1) of measure epsilon away from full

yeah but even after some large n

you need uniform conv for that

PNDas

Yes you are right

I didn't think of that at that time. I did that like in the last five minutes.

porridgemathematics

16:10

its a tricky question

PNDas

I guess I would get around 35.

@porridgemathematics She said you need to apply Vitali convergence

I didn't even know that theorem.

one potato two potato

@XanderHenderson you passed qual after a year. then after that, did you just take mandatory courses or did you self-studied some topics you're interested in? possibly advisor instructed you what to read?

porridgemathematics

vitali convergence would work

but I can think of a way without using it

Xander Henderson

@onepotatotwopotato In your first year, you were required to take two "core" classes (analysis, topology, complex anal, algebra, or PDE), and could take a more specialized class in your second or third quarter.

porridgemathematics

so I wouldn't say you need to

Xander Henderson

16:16

In your second year, you were expected to take two more core classes, and two more quarters worth of more specialized classes.

So that is what I did.

I also attended seminars run by the two faculty I was most interested in working with.

one potato two potato

reading seminars?

Xander Henderson

@onepotatotwopotato Baez's seminars were very lecture-y---it was mostly him talking about what he and his students were working on.

PNDas

@porridgemathematics How?

Xander Henderson

Lapidus' seminars were much looser. Usually, each meeting would be a 45 minute talk by one of his students or another guest speaker, followed by 30 minutes of questions, then a three or four hour lunch.

lone student

@XanderHenderson Hello .

porridgemathematics

16:21

@PNDas you can use uniform integrability and egorov.

basically

the hint is to use egorov to get f_n -> f uniformly outside a set of small measure

PNDas

They didn't teach uniform integrability, Vitali. I think that it was kind of unfair but I guess these are just excuses.

geocalc33

anyone like rufus du sol?

porridgemathematics

then control the integral on the set of small measure using the uniform boundedness in L^2 (hence L^1) norm hypothesis

you don need to know anything apriori

uniform integrability here is implied, but you can just use egorov and the assumptions

geocalc33

open.spotify.com/track/…

PNDas

Hmm

porridgemathematics

16:23

and dominated convergence

those three tools will get you the answer

also finiteness of your measure space

PNDas

Ahh yes. I get your point. it was easy.

I am just dumb.

porridgemathematics

the uniform boundedness in L^1 of the f_n;s allows you to control the integral over the set Egorov fails

that's the gist of it

nah not at all

I think this was genuinely tricky

one potato two potato

@XanderHenderson people usually talk about their work? or what they're studying? If you don't have enough background knowledge to understand what they're saying, what do you usually do during the seminar?

Xander Henderson

@onepotatotwopotato They talk about their work.

The thing is, if you attend a working seminar often enough, even if you don't know what the heck they are on about on day one, you start to pick up the shape of things.

So even if you feel like you aren't understanding anything, some part of your brain is putting things together.

geocalc33

some part of your brain is putting things together

I like that

one potato two potato

16:38

I usually note some keywords that I don't know but repeatedly used during the seminar and search for them after it's finished or ask the speaker where can I learn. In that way I kind of road map myself what to know to study that area.

porridgemathematics

17:15

@onepotatotwopotato hey, I came across a question of yours on Riemann surfaces, I commented on it with what I think may be an answers (if you still need one)

冥王 Hades

17:27

The main page of the site is filled with badly written questions and other nonsense

Thats what happens with the moderator strike

Ted Shifrin

I vote to close many questions.

PNDas

I am not able to focus. I just keep getting the thought that if only I had done blah blah it would have been blah blah.

I'm just sad. I have probability qual next week.

I am just wasting my time, can't study.

冥王 Hades

Xander Henderson

@冥王Hades To be honest, the moderators don't do a lot to deal with the flood of garbage on the front page. Our hands are very tied by the will of the the community.

So it is unclear how much the moderator strike is effecting that.

On the other hand, there area lot of flags which haven't been handled.

冥王 Hades

17:44

Some of those flags probably include such posts, and because they haven’t been handled, a lot of them also haven’t been removed as they normally would be

David Raveh

My PDE professor said that he was on attending a thesis defense for a student, and the student was asked to prove the Pythagorean Theorem. The student said, "I can't, but I could always look it up if I ever need it," to which they responded "you need it now."

Xander Henderson

@DavidRaveh That's kind of an unfair question, devoid of further context. I mean... what constitutes a proof? What do you get to take as given?

That being said, every student should have a few proofs hand for any occassion.

A proof of the Pythagorean theorem, a proof that $\sqrt{2}$ is irrational, a proof of the infinitude of primes, and a proof that the reals are uncountable.

At a minimum. If you can't do those at a moments notice, you don't get a phd. :P

冥王 Hades

I did a nice proof of Pythagorean theorem 3 years ago using….pentagons. I’m sure something like that existed before but to me it was a new result

Xander Henderson

@冥王Hades There are a lot of proofs of that theorem.

My favorite is one written by Garfield (an American president).

It has a certain minimal elegance to it.

冥王 Hades

Yeah I’ve seen Garfield’s proof.

Einstein also did one.

David Raveh

17:59

I remember coming up with the rearrangement proof, and wondering if there are any others. There are hundreds :)

冥王 Hades

Maybe that should be our voting criteria. A president is only allowed to run if he can submit a proof of well known theorems

Soumik Mukherjee

18:20

@PNDas I can understand what you're going through, for the past few months, I was at that position too. But again, nothing will change no matter how hard you think about it now, so try to let the past go.

lone student

18:37

@冥王Hades I had solved the 3rd and 4th degree polynomial equations in highschool, but then I found out that they were already solved. However, the method I use is not mentioned in Wikipedia. However, I still think someone else probably did.

noballpointpen

Hey. There is a seemingly "tricky" problem in Rudin's PMA. Ex. is 4.19:
Suppose $f$ is a real function with domain $R^1$ which has the intermediate value property. Suppose also, for every rational $r$, that the set of all $x$ with $f(x) = r$ is closed. Prove that $f$ is continuous. Hint: If $x_n\to x_0$ but $f(x_n) > r > f(x_0)$ for some $r$ and all $n$, then $f(t_n) = r$ for some $t_n$ between $x_0$ and $x_n$; thus $t_n \to x_0$. Find a contradiction.

For me it seems that it is immediate answer, since $t_n$ proves that $x_0$ is a limit point and $f(x_0)=r$, contradiction. I must be missi…

Xander Henderson

18:54

I'm not quite seeing the entire shape of your argument.

$x_0$ is a limit point of what?

Why is $f(x_0) = r$, when the hypothesis is that $f(x_0) < r$? (I know, this is your contradiction---it isn't clear to me how you arrived at it.)

noballpointpen

We have $f(t_n)=r$ for every $t_n$ and $t_n \to x_0$, so $x_0$ must be a limit point of the set of $x$ for which $f(x)=r$. And it is closed.

Xander Henderson

It may just be a matter of phrasing, but something seems to be missing. In my opinion, it would be better to say something like "For each $n$, $t_n$ is an element of $f^{-1}(r)$ (the preimage of $\{r\}$ with respect to $t$). The sequence $(t_n)$ converges to $x_0$ (since $t_n$ is between $x_0$ and $x_n$ for each $n$, and $x_n \to x_0$). But $f^{-1}(r)$ is closed, and each $t_n$ is in this preimage, hence $x_0$ is in $f^{-1}(r)$. Therefore $f(x_0) = r$, which is a contradiction."

@noballpointpen If I were reading this in a paper, no problem. If I were grading this, I would likely mark you down a little for not explaining why $t_n \to x_0$.

The point of exercises like these is to spell out all of the "obvious" or "trivial" details.

Since nothing is obvious, and trivialities often turn out to be harder than we expected.

Thorgott

Also, to get the to the point of "$f(x_n)>r>f(x_0)$ for all $n$", you have to do some sort of passing to a subsequence and WLOG argument

noballpointpen

Thor, you mean a case when $f(x_n)$ could alternate between left and right of $f(x_0)$?

Xander Henderson

@Thorgott Indeed. I was taking that as given, since Rudin gives it, but a couple of words would help that along.

Thorgott

19:07

yeah, that's what I mean

(it could also equal $f(x_0)$ for some $n$, too)

noballpointpen

Thanks, Xander, Thor.

copper.hat

19:21

buenos dias

冥王 Hades

Using vectors to solve problems is in analytic geometry feels like cheating

Xander Henderson

@冥王Hades Okay. So tie one hand behind your back, and don't use them.

Whatever floats your boat.

Pops your cork.

Wets your whistle.

冥王 Hades

19:49

@XanderHenderson I can tie both behind my back and write using telekineses

Xander Henderson

As I said, whatever gets you off.

3

copper.hat

tempted to star that advice out of context :-)

call 1-900-get-math

leslie townes

20:46

math.stackexchange.com/questions/4729359/… free internet points for someone whose french is better than mine. pretty cool question, imvho.

a lot of textbooks include some version of the R^1 result but i have not seen it done in R^2.

Ted Shifrin

20:59

I can translate a particular passage for you, but I’m not interested in reading the paper.

leslie townes

oh no, the paper's huge. and not for me. the guy's asking about something in a construction at the very end of the paper.

probably "caring about banach limits" is a prerequisite.

:)

Ted Shifrin

Are they beyond the Milky Way?

leslie townes

i'm just relieved to see someone citing an old source that isn't some 19th century opium hallucination in language that takes longer to explain than the math does.

they really shouldn't call them banach limits, they should call them banach NO LIMITS.

copper.hat

defund Banach

leslie townes

the paper there is banach, constructing invariant measures in R^1 and R^2 as corollaries of some general theory that some people still use. i think right before he discovered the banach tarski paradox in R^3. interesting time to be alive.

copper: no, we should fund banach.

copper.hat

21:11

seems to be the rage

reminds my first landfall in Cherbourg, we were all amused by the big signs marked LA RAGE.

Banach Tarski would solve a lot of world problems.

s.harp

I recently read parts of Riesz paper showing fredholm operators ahve finite index, that was a surprisingly nice old paper

leslie townes

some of those old arguments still work! :)

s.harp

also have you got any examples of 19th century opium hallucinations math papers? that would be interesting just for the novelty alone

copper.hat

i did stay in a place once that had an active opium den. not my sort of thing really.

s.harp

also Riesz paper on whats now called Rellich theorem in R^2 (I think?) is also readable as hell

leslie townes

21:21

oh haha i was just joking about old texts using geometric language and other language that you need a lot of background to understand, if you aren't trained with a ton of 19th century 'intuition.' i assume everyone in the late 19th century was on opium, but maybe not to the point of hallucinations. just to get rid of the early afternoon "blahs"

copper.hat

just had a rare moment when my intuition with complex analysis is correct.

i deleted all my 'this is not a proof' comments, so not amusing to read anymore.

leslie townes

sharp some of that (but not the rellich result, i don't think?) is in his functional analysis textbook with sz.-nagy. nobody uses it anymore but it is a good compilation of a lot of slick proofs from those papers.

oh, maybe the rellich thing is the other riesz, now that i think about it.

s.harp

Wait, are you saying there is more than one Riesz?

Marcel and Frygies Riesz lol

leslie townes

yes, and they're brothers who published in related areas at around the same time.

i'm sure even they had trouble keeping it straight.

s.harp

Frygies looking like a magician

leslie townes

21:26

dripped out mathematicians

s.harp

this guy did that opium for sure

copper.hat

indeed, they were known as the wild rice brothers.

s.harp

Wikipedia says this about Frygies: He had an uncommon method of giving lectures: he entered the lecture hall with an assistant and a docent. The docent then began reading the proper passages from Riesz's handbook and the assistant wrote the appropriate equations on the blackboard—while Riesz himself stood aside, nodding occasionally.

leslie townes

it's funny that they say it's "uncommon." largely because of that story, i've always sort of imagined everyone in continental europe lecturing like that.

copper.hat

those decadent continentals

the rte, who broadcast the wonderful 'where's granddad' ads, is undergoing some bit pay controversy atm

冥王 Hades

21:43

Did SE ever stop being disingenuous and gave a genuine response to the moderator strike?

copper.hat

i did not follow it. i tried reading a few times but got lost.

oh, did you mean the ai strike?

chatgpt gives: "As an AI language model, I don't have real-time information or access to current events beyond my last update in September 2021. "

apparently it cost around $100m to produce the model for chatgpt.

mick

21:59

Im really sick of all my questions getting closed.

One day I will probably find all of them closed wont I ?

I am still unwelcome here

why do I even bother

Maybe I should leave and delete it all

and why are the chats always so empty

copper.hat

i cannot comment on the reasons behind the closers, but generally zeta function questions and answers that seem to relate to unproven hypotheses tend to be from cranks.

so perhaps the closers are just jumping the gun.

mick

its always that " context BS "

copper.hat

i know little about the zeta function other than i like writing the Greek letter $\zeta$.

mick

and maybe I am a crank , but closing wont improve that

leslie townes

that's often what it is. "hi, here's something that sounds kind of like a famous problem" has people reaching for the close button and looking for reasons later.

"put more context, what attempts have you done, why is this relevant, this is isolated" is also overused, as a reason to close.

copper.hat

22:04

i am a crank, but i stay away from real mathematics.

unless it involves $-{1 \over 12}$.

mick

I did not even mention Riemann at first.

copper.hat

everyone knows where it is going...

mick

its not just zeta stuff, anything not typical is closed

even my highest rated question was once closed

copper.hat

i have only looked at lightweight stuff recently, so have no data to support or deny that

leslie townes

there should be a default reason to close that's something like "this seems to resemble a research program more than it does a single question." there's a general, non community specific option called "needs more focus" which comes close, but is not quite that.

copper.hat

22:07

i think the reality is that you need to establish bona fides before straying into the rarer atmosphere

mick

closing without constructive feedback should be forbidden

copper.hat

same with downvotes imo

leslie townes

i'm in the middle, i think that downvotes should require comment, but i'm ok with votes to close not requiring comment. :D

copper.hat

i rarely downvote, but actually did so twice in the last week.

i give reasons.

s.harp

Can I foliate R^n \ {some singular set} by S^1 x ... x S^1 (n-1 copies)?

copper.hat

22:08

the ops responded, in one case i was wrong, apologised and removed.

s.harp

For R^3 it comes from Hopf, rest I dont know

mick

bona fide , yeah but I have been here for a decade !!
Still do not thrust me ?? my 14k rating and 10 years mean nothing ?

Sure I am no expert , but what is " bad intentions " even suppose to mean ???
I am not making money or getting fame and I am not trolling

leslie townes

you're not making money or getting fame? clearly you need to read my book on how to use MSE. it's on sale in my bookshop.

copper.hat

what about leslie coin?

leslie townes

there's a pamphlet on that too, free with purchase of the book.

mick

22:11

and another thing , sometimes I find 3 yo questions closed.
That is rediculous.

copper.hat

well, i think the closing crew are not as aggressive as in the past.

s.harp

the crude chatroom collapsed due to AI protest or somethung i guess

mick

that is because of inactivity rather than change i think

I signed the AI petition

copper.hat

is there an one line explanation about what the issue is?

mick

there are not many online , yet those that are , are like closing ... so the closing mentality is the same.

copper.hat

22:14

something simple that even i can understand?

mick

and its not just my posts , i see others being closed too once they are " out of book " , and the irony is we do not want homework questions , but it seems only those are " safe "

s.harp

@copper.hat people think AI generated content in posts should be either banned or disclosed by the writers, SE thinks "fuck off"

copper.hat

@s.harp thanks. i think in this case i would disagree with SE

i mean i vehemently disagree

mick

sign the petition @copper.hat

there have been privacy issues, safety issues , now AI ...

copper.hat

where is it?

but, really, what about my jumpsuit?

i can't find the petition.

mick

22:19

openletter.mousetail.nl

you can sign it there

copper.hat

reading

thanks!

mick

i got there via meta

the strike is a top post on meta and so one

Now if anyone here voted close , tell me , i do not like fake friends or hypocrites

btw , I considered changing my password , but I do not use that mailbox anymore ... how to change mailbox thing and such ?

ah i found mail

but not how to change password

never mind

found it

copper.hat

signed

i did not. unless it is spam, i always post any negative intentions first.

mick

i have year rank #253.

Yet my questions get closed all the time, I am not taken seriously etc

it that no silly ?

copper.hat

but i am not generally an enforcer, just a noise maker

mick

22:28

im gonna read a book

and some notes

copper.hat

i can understand why you would be annoyed, but the responses unlikely to change if you deal with unproven, well known hypotheses

mick

i remember Hilbert saying that imagination is important for mathematics.

I feel closing crazy ( but consistant ) ideas contradicts that

copper.hat

i am more than a little surprised to see that i am still on the first page of the lifetime user rep page

mick

but it is similar , but not super similar.

For instance , a random dirichlet series is not as hard as the Riemann hypothesis

or we should ban dirichlet questions all together

but where will such logic make us end up ??

copper.hat

i have no comment regarding them to be honest, i am an enginner

i deal with the mundane

mick

22:31

Downvoting an answer without comment is also ... I dunno ...weird and impolite at least

imo

people do not loose enough for downvoting lol

I do not understand all that hate

suppose math teacher be like that ??

your answer is correct , but im gonna fail you anyway

without feedback

copper.hat

yep, a downvote us not equivalent to the opposite of an upvote

mick

a valid proof is a valid proof.

whats not to like

its rediculous

or even a valid argument if nobody can give a proof

i need to cool down

copper.hat

have a drink

mick

not like that

copper.hat

its approaching wine o clock here.

Ted Shifrin

22:47

Is wine o'clock more than an hour before martini hour?

copper.hat

anytime after local noon :-)

Ted Shifrin

oh, geez, I'm way behind

$Mathematics$ Number theory

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$Mathematics$ Mathematics