tea.mathoverflow.net - Category Feed (General)

Discussing recent preprints on MO (again)

2012-08-16T02:50:35-07:00

This question is currently in the middle of a close-reopen tug of war. It would be better if those involved discussed the pros and cons on meta.

I am very concerned by this question, and also by the responses we are seeing. A year or so ago, we discussed whether or not MO should be used to discuss the merits of recent preprints here and also here. Various views were expressed, but I think there was general agreement that MO is not an appropriate venue to discuss recent preprints in detail and that authors should be treated with respect.

Unfortunately, the responses to 104695 violate both these principles; in particular, the author has been ridiculed. I am very concerned about what this means for the culture of MO.

Asking for help: a question on editorial system of AMS journals

2016-01-18T14:03:58-08:00

Dear MathOverflow community,

I'd greatly appreciate your help with following question on the AMS journals :

http://academia.stackexchange.com/questions/61805/confusing-article-status-for-journals-of-american-mathematical-society-reviewi

either directly at academia.SE, or perhaps, if deemed appropriate, after migration to MO.

Many thanks in advance.

Green-Tao endorsed answer on Green-Tao theorem

2010-07-17T17:33:02-07:00

There are probably some people who haven't seen this, and who may enjoy it as much as I do:

http://mathoverflow.net/questions/25402/is-the-green-tao-theorem-true-for-primes-within-a-given-arithmetic-progression/25403#25403

I'm just posting this to make it more well known. I'd be interested if anyone would like to comment with links to similar posts.

DuckDuckGo and MathOverflow

2014-06-23T19:31:18-07:00

I recently used DuckDuckGo to search the phrase "remainder number theory" and the first entry (under "Q/A") was an old 2010 question from MathOverflow. (See the screenshot here: http://i.stack.imgur.com/HtnDJ.png)

(The MathOverflow link is to http://mathoverflow.net/questions/19076/bringing-number-and-graph-theory-together-a-conjecture-on-prime-numbers#19080)

Fake tea?

2013-11-11T05:41:10-08:00

The website with the URL http://mathoverflow.tqft.net/ looks exactly like this one. Are they the same site?

Edit: right after I posted this, the other website instantly updated and showed this question. So it seems that the two websites are "the same." (It also seems that the domain tqft.net belongs to Scott Morrison.) But why am I signed in here, but not signed in the other website?

Comments on Minimal Models of ZF

2013-12-02T19:21:35-08:00

Here is the full comment thread on question http://mathoverflow.net/questions/150474/

Please ask a different question; it's impolite and pointless to make a deep edit after accepting an answer. François G. Dorais♦ 1d ago

@FrançoisG.Dorais: I unaccepted the answer. Please return the question to the previous form. Thanks. Saint Georg 1d ago François G. Dorais♦ 10h ago Saint Georg

1 Saint Georg, that is a very impolite thing to do! Please reaccept Joel's answer! François G. Dorais♦ 1d ago

Comments on Subsets of Real Numbers

2013-12-02T19:13:00-08:00

Here is the full thread of comments for http://mathoverflow.net/questions/150459:

8 The definition, and therefore the question, makes no sense. ZF can prove only formulas, and sets of reals are not formulas. You could define that a formula $\phi(x)$ is a "definition of a choice-free well-orderable set" if ZF proves "there is a well ordering on ${x \in \mathbb{R} : \phi(x)}$", but this will not help, as the definition of $A$ and $B$ then still make no sense. In the metatheory, there are only countably many formulas, so the set of all definitions of c.f.w.o.s. is trivially countable, whereas from within the theory, you cannot express the property of being definable by ... Emil Jeřábek 1d ago

1 ... a first-order formula, hence the informal collection of sets defined by a formula that is c.f.w.o. is not a set, and as such you cannot speak about its cardinality. Even the collection of all definable sets in a model is not preserved by elementary equivalence, and it models where it happens to be an internal set after all, it may well be anything from countable to the full powerset of the reals. Emil Jeřábek 1d ago

1 And of course, one set in a model can be definable by two different formulas, one of which may be c.f.w.o., and the other one not. In fact, every definable set has a definition that is not c.f.w.o. Emil Jeřábek 1d ago

What do you mean "find"? I'm getting confused by your edit, because sets are semantical objects for set theory. This means that in a given universe some sets of reals will be well-orderable. You don't use the axiom of choice to "find" these well-orders, they exist. Is you are talking about definable subsets that's a whole other thing. I think that the right question, and indeed this is what I interpreted from the question originally, is asking for the set $A={X \subseteq \mathbb{R} | X \text{\ can be well-ordered}}$ and asking what can we prove about the cardinality of $A$ in ZF, [cont.] Asaf Karagila 1d ago

@EmilJeřábek: How can one define the "clear" notion of a choice free well-orderable set? Is Asaf's answer meaningless too? If not, is it answer of a question different from my question? If yes, what is that question? Saint Georg 1d ago

1 My answer, was, it seems (and I agree with Emil) to a slightly different question. About what is provably true about ${X \subseteq \mathbb{R} | X \text{\ can be w.o.}}$, and about its complement. Note, to your edit, that sets are the semantical objects in set theory. If $A$ is a set of reals in a model $M$ either it can or cannot be well-ordered, and the axiom of choice says nothing about it. If we want to ask whether or not every definable (with real parameters?) set of real numbers can be well-ordered, that's another question (whose answer is similar to mine), which admits consistency results. Asaf Karagila 1d ago

12 Saint Georg: The appropriate way to react to Emil's criticism is to take some time to digest it, not trying to argue that your question makes sense. Over the past two days or so, you have asked 5 questions and at least 3 had deep flaws demonstrating lack of research. Perhaps you should ask questions on Math.StackExchange until you reach the point that your questions meet the standards expected by the MathOverflow community. François G. Dorais♦ 1d ago 9h ago

@FrançoisG.Dorais: Was my comment "trying to argue that my question makes sense"? I simply asked about the probable problem because in the first view it seems that Asaf had no problem to understand my question and I had no problem to understand his answer. I asked them (Asaf & Emil) to illustrate the problem more and I received useful explanations. Saint Georg 1d ago

Comments from http://meta.mathoverflow.net/questions/895/how-to-contact-moderators

2013-09-28T11:03:22-07:00

Here are the original comments for the title question:

When I google "Ben Webster math", his webpage is among the first few listed. – Andy Putman 13 hours ago
Also, the old meta is now at tea.mathoverflow.net. The search functionality is lousy, but google is perfectly capable of searching through it. – Andy Putman 12 hours ago
@AndyPutman : Obviously I googled "Ben Webster math" before posting this and his webpage was among the first few listed. The page doesn't work. – Michael Hardy 12 hours ago
At any rate, some way of contacting moderators should be provided. – Michael Hardy 12 hours ago
You might choose your words with more care. "Concern" is a good choice, whereas "organized abuse" may keep your claim from getting due recognition. Good luck with your pursuit. – The Masked Avenger 12 hours ago
@TheMaskedAvenger : Regardless of whether I say "concern" or "organized abuse", attention to such a thing from the moderators is obligatory. That's what they sign up for. And if there's organized abuse, is it not the job of the moderators to take cognizance of it? – Michael Hardy 12 hours ago
@MichaelHardy : Uh, I just visited it and it works fine. It's here : people.virginia.edu/~btw4e – Andy Putman 12 hours ago
@AndyPutman : This is the page that I found: mathserver.neu.edu/~bwebster At any rate a way to contact all six moderators should be provided, rather than requiring those with concerns to be brought to the moderators' attention to see what they can do without any such way. – Michael Hardy 12 hours ago
@MichaelHardy : Ben moved from Northeastern to UVA, effective this academic year. – Andy Putman 12 hours ago

Bounty madness

2013-06-27T11:09:39-07:00

Half of our current “featured questions” list consists of three questions by a user well known for his peculiarity, whose combined total of -18 votes doesn’t leave any doubt that they are regarged as terrible by the community, and which already have satisfactory answers anyway. Each question was awarded a 500 bounty by Frictionless Jellyfish on the grounds that “one or more of the answers is exemplary and worthy of an additional bounty”. Do we really want this?

Update MO to better deal with the unknown

2013-06-10T10:19:26-07:00

Hi,

I think MO is a great tool for the mathematicians, but I think also that it's time to go into high gear.
The research in mathematics cannot be reduced to: ask a "good" question and respond a "good" answer.
In my opinion, the research needs to be less rigid than that, and much more open.

What's research? It's dealing with the unknown.
Do you think it's a good strategy to deal with the unknown only with questions which are well written regarding to the known part of the knowledge?
You lock yourself in the existing concepts...

Of course, I don't suggest being less rigorous, what I say is that we can authorize yourself a new step on the mathematics activity:
a visionary step, before the rigorous step.

So ok, the research activity not reduce to MO and most of you have (of course) an intuitive, visionary or fantasy level in their research activity.
My point is that MO is a social network, so it's very sad that we can't interact at this level.
I think it's possible: you interact at this level with yourself, why can't you do the same thing with others?

So ok, I can already hear the responses saying that if we allow this, it's going to become rubbish.
It's the reason why I propose to update MO, in the sense that you divide the questions section into two parts:
a rigorous one and a visionary one, with some restrictive conditions, for example:
- To post a visionary question, a user need to have more than 250 points of reputation.
- Every visionary question need to be attached to a rigorous one.
...

Also, remove the up and down votes for a visionary question (because it's nonsense to judge the subjectivity), but keep the stars and the view counting.
And of course, the rigorous (resp. visionary) answers are not restrict to rigorous (resp. visionary) questions: these two aspects can interact.

Maybe any of you will cite many forums where such interactions already exist.
I respond that if we are looking for such interactions at a professional level, there is much less.
And also that the important advantage is that the two aspects (rigorous and visionary) are possible in a unique place, to interact between them.

You can say to me that what I propose is technically impossible because the StackExchange 1.0 software engine not allow such modifications.
I respond: update the software too!

Finally, you can think that it's nonsense to do what propose an "outsider", a young beginner...
I respond: << out of the mouths of babes and sucklings comes the truth >> ... :)

So deal with your own consciousness.

Sébastien.

Question to be closed

2013-06-11T15:33:03-07:00

Could we close this old question http://mathoverflow.net/questions/28764/status-of-beal-granville-tijdeman-zagier-conjecture ? It's just attracting crank answers. The fact that the prize money was raised is no reason to rekindle the discussion. Thanks.

Closed threads being considered for deletion, perhaps controversially

2013-05-30T04:33:25-07:00

I thought I'd start a thread that systematically identifies closed threads with at least one delete vote, but for which deletion could be considered controversial -- for example, if the thread has some answers.

To start things off, I present:

http://mathoverflow.net/questions/127190/is-there-an-observer-dependent-mathematics-closed

Who is voting these up?

2013-05-29T04:37:32-07:00

The voting on this answer does not seem normal: http://mathoverflow.net/questions/18375/is-there-any-finitely-long-sequence-of-digits-which-is-not-found-in-the-digits-of/132035#132035

The answer is wrong. It received 5 down votes, then 3 up votes, then another down vote (which is how the author currently has 29 reputation). Some of the people arguing with the author have made incorrect statements about trivial things, and have made other questionable statements, but it is still odd that so far 4 of AGreen's comments received exactly 3 up votes, too, comments including statements like, "But in order to have an absolute proof, you need absolute information. This is given by the laws of physics... That is a proof completely independent from assumed axioms. It holds for mathematics, because mathematics happens in the real world." I would not expect that to be voted up 3 times. The most plausible explanation to me is that those all of these up votes came from the same 3 accounts, and that they are the same person.

MO statistics

2013-05-28T10:12:50-07:00

Mainly out of curiosity, is there a place where one can find MO statistics? Like the number of single users that visit it every day? every month?
The number of posts every day, of answers, of comments ? The number of users with more than x reputation points ? and the evolution of those variables over time?

MO public database dumps

2010-03-03T23:02:54-08:00

Here's the first public dump of the database. It's from earlier today.

http://dumps.mathoverflow.net/, or
http://ifile.it/soyqa09/MOdump20100303.zip

Problematic question.

2013-04-09T14:34:33-07:00

After 35 years as a programmer, avoiding one-off problems, I make that rookie mistake with this question: http://mathoverflow.net/questions/126739 as Douglas Zare pointed out. My first clue should have been my own statement, "This is not a sum that I expected."

A reworking of the question to start the sums at zero instead of one, would change the convergence to 1, and make everthing else confusing. So, I would like to delete the question, but some may not want their work to disappear. (I have an off-line copy.) I don't think the OP has any archival value, but what do you think?

Late upvotes

2013-03-30T00:58:51-07:00

Almost exactly one year ago I answered this question.
In the last few hours I got four upvotes for my answer.
I am of course happy about them, but I am also curious: why should four users become simultaneously interested one year after the question came up?
Since it is not the first time that I notice this phenomenon, I thought someone here on meta could explain it.

Should MO have a 'homework' tag?

2013-02-25T05:44:54-08:00

Recently the tag 'homework' was created.

In my opinion to have a homework-tag on MO is rather potentially harmful as it is likely to give the wrong impression that homwork-questions are on-topic (why else should such a tag exist, could be an IMO reasonable line of reasoning of a new user).

Indeed, that is why I suggested the deletion of a then existant tag of the same name some time ago (which happened). It now was recretated, by a very experienced user. So I did not just want to remove it but rather thought to start this thread.

Added: for reference this is what I said on the respective sticky thread Dec 4th 2011 (towards top of page 5) [To avoid a misconception, the user using it then and now are different.]

I just noticed that there is a (recent?) 'homework' tag and somebody (not OPs) tagging things with this. For several reasons I think having this tag is a bad idea. One is that it can suggest homework is on-topic.

Am I too uncharitable regarding this answer?

2013-03-01T10:24:58-08:00

Some hours ago I found a new answer in the Experimental Mathematics question http://mathoverflow.net/questions/12085/experimental-mathematics/123321#123321 [added: meanwhile also gone] to which I reacted quite harshly, downvote and flagged as spam. The reason for the latter is that this very same vixra-preprint got already mentioned I think at least three times on the site; an occassion I definitely could track down from just 10 days ago http://mathoverflow.net/questions/110944/what-does-the-numerically-verified-part-of-the-riemann-hypothesis-tell-about-prim/122295#122295 [deleted so not generally visible] then posted from a different (anonymous) acount with not much activity but trying to stir up in a in my opinion strange way some discussion around this same subject some 20 days earlier http://mathoverflow.net/questions/120017/why-mathematicians-do-not-accept-the-wu-sprung-semiclassical-model-as-a-solution [again deleted].

The current posting is from a completely new account, which I however suspect to be not independent, without much evidence beyond doubting two independent mentions of that vixra-preprint.

Yet so far I stayed somewhat alone in my harshness; which suggests it is perceived as overly harsh or the thing was just not yet generally seen. In either case, I thought asking here was a good idea.

Please delete open ended question on tetration

2013-02-14T17:31:50-08:00

One of the highest ranking selections for tetration on Google is the following Mathoverflow question - http://mathoverflow.net/questions/45277/how-close-are-we-to-extending-tetration-to-the-real-and-complex-numbers . This question was closed as not being a proper question and has only one answer that is not very helpful. Could someone please delete the question? Thanks.

Deleted Users' Questions

2013-02-07T01:09:46-08:00

Dear Friends.
I want to discuss the Information event:deleting Users contents(removing from public access).
Then User's questions/answers/comments have been deleted(remove from public access)
This is unpleasantly. I understand.

Formally, without direct reference(url) on server(mathoverflow), clients'(Users') copyrights(and allied rights)are questionable.

In such situation(deleted questions/answers/comments), client lost rights on the time of publication(priority date) and file of question.
That can lead to situation when client to be forced "ask someone for permission" (reference on someone ) for developing his own(client's) ideas.
In fact, has been published early(actually removed from public access and no references).

This looks like the copyright(and allied rights) violation from the priority rights side.

For avoidance of it is suffice for client to have server's urls of
all his own content, even without public access.

If User asked question, that cause interest of other Users, in form
of answers or comments(rights of Users that create these), this is hystorical document, useful
Information. I think so.
What do you think?

Thanks.

Should I delete this question?

2013-01-05T21:24:41-08:00

http://mathoverflow.net/questions/118044/an-isomorphism-between-different-exts-coming-from-group-cohomology

After posting and receiving comments and answers, I realize this wasn't an appropriate question in the first place, for two reasons:

1) The premise was false, as I overlooked the following subtle point: a central extension of abelian groups need not be abelian
2) The answer was a basic fact in group cohomology (and I knew enough group cohomology to do algebraic number theory, but I hadn't, say, read an entire book on group cohomology)

So, in a case like this, should I delete this question? I ask not only because of this particular question but because it has implications for MO in general.

Discussing work in progress in answers

2012-12-20T09:39:31-08:00

There is a question that's been asked for which I can give an answer to a related question (but not the same question). The problem is that the answer relates to work in progress which won't be out for a few months, and this work is of the type that a fairly significant number of experts could also figure out the answer (or how to derive the answer), so there is a reasonable possibility of getting scooped.

Now it is fairly established that putting a preprint on the arXiv establishes priority (or at least independence), but would answering a question on MathOverflow do the same? Would it be better in this situation to give more details or fewer? (The answer is one line, a reasonable sketch of the proof fits in the answer box, and the paper (which will include a generalization) probably won't go over 10 pages.)

Reopening "foundational theorems of logic"

2012-12-02T13:55:36-08:00

Upon checking MO today I found out that my question was bumped: http://mathoverflow.net/questions/85946/an-undergraduates-guide-to-the-foundational-theorems-of-logic-closed

Since it is already bumped, I was wondering if via possible reformulation, the question can be reopened? Many young students like me would benefit immensely; although this is a research level site, the fact is to explain the concepts in expository terms, there is no other better forum than this one with experts.

I am willing to change the question to: Examples of applications of foundational theorems

(1 each, CW) with OP reading:

Formal definition of Goodstein's theorem: "Every Goodstein sequence eventually terminates at 0.
The Goodstein sequence G(m) of a number m is a sequence of natural numbers. The first element in the sequence G(m) is m itself. To get the next element, write m in hereditary base 2 notation, change all the 2s to 3s, and then subtract 1 from the result; this is the second element of G(m). To get the third element of G(m), write the second element in hereditary base 3 notation, change all 3s to 4s, and subtract 1 again. Continue until the result is zero, at which point the sequence terminates."

Example by analogy: "Laurie Kirby and Jeff Paris gave an interpretation of the Goodstein's theorem as a hydra game: the "Hydra" is a rooted tree, and a move consists of cutting off one of its "heads" (a branch of the tree), to which the hydra responds by growing a finite number of new heads according to certain rules. The Kirby–Paris interpretation of the theorem says that the Hydra will eventually be killed, regardless of the strategy that Hercules uses to chop off its heads, though this may take a very, very long time."

http://en.wikipedia.org/wiki/Goodstein%27s_theorem

Is it associated to or associated with

2012-11-25T19:47:39-08:00

Hi, Folks. A student of Ken Ono just sent me a very nice item related to my stuff, where he shows GRH implies everything in my list of probable widgets actually is a widget. About three times a page he says something is "associated to" something else, which grates on my nerves a bit. However, i can see that this might be standard usage in the modular forms industry. The difference, I guess, is that the first item is being assigned to the second item. Here's one,

"We say that a ternary quadratic form Q is associated to an elliptic curve E/Q if the cuspidal part of its theta function is a Hecke eigenform which lifts, under the Shimura correspondence, to the cusp form associated to E."

So, two associations in one sentence.

Just hoping for feedback here. I don't see this as a successful MO question. Also, I am not obligated to comment on the language. But I could...

Dumps data

2012-11-27T01:32:17-08:00

I didn't know where to place this question so I placed in under General.
I need help from the website support team.
I downloaded you dump file posts.xml and Use it's data (thanks by the way).
The problem is that some questions that appear in the dump under a certain ID return 404 when I try to link them with: http://mathoverflow.net/questions/[ID]
for example: http://mathoverflow.net/questions/47579. the ID 47579 appears in the dump with the title: "Help with simplifying a simple infinite series".
But you can try and see that mathoverflow.net can't find it.
What is the reason for this and how can I recognize records in the dump that don't really exist in the site?
Thank you for any help.

Can someone unlock my question?

2012-11-20T14:03:39-08:00

For some reason my question(http://mathoverflow.net/questions/110857/can-we-ascertain-that-there-exist-an-epimorphism-g-rightarrow-h) was listed as answered while it does not have a good answer. Can the moderator unlock this into the unanswered category?

Deleting junk questions

2012-11-18T13:38:14-08:00

I notice that some junk questions, even though closed and down-voted, still linger on the page for a while. These are questions that every established user of the site would agree are obviously inappropriate, without a moment's hesitation; I don't mean borderline questions that perhaps some members would allow. It might not be correct to classify junk questions as spam, because they could have been posted by hand and have some elementary mathematical content. Is there potentially a fast track for removing such questions?

What are good MO questions in your opinion ?

2012-10-28T11:50:10-07:00

What are good MO questions in your opinion ?
What "good" means for you ? Can be various meanings "beautiful", "helpful for research", "exciting" ....

Various discussions have already naturally come to this question
I think it would be valuable to exchange opinions about this in separate thread.

Let me collect some quotes:

JDH Jul 15th 2012
http://tea.mathoverflow.net/discussion/749/relation-between-mo-mse/#Item_12

... If the site should become populated only by super-advanced, highly technical questions, as some seem to have advocated, then I would simply expect the site to whither, with fewer and fewer participants, since even knowledgeable users will find less and less of interest, and so they won't be here to answer those advanced questions for which they do know the answer.

Joseph O'Rourke Jul 21st 2012
http://tea.mathoverflow.net/discussion/749/relation-between-mo-mse/#Item_21

Among the most valuable aspects of MO for me personally has been the instances when knowledgeable mathematicians take the time to post illuminating answers to naive questions, for example:
Why is a topology made up of open sets?
Is the boundary ∂S analogous to a derivative?

"If the site should become populated only by super-advanced, highly technical questions" (JDH), we would lose this enjoyable educational aspect.

quid 4 hours ago
http://tea.mathoverflow.net/discussion/1447/3/evaluation-of-potentially-credible-papers-should-be-allowed/#Item_16

Let me give you an example of a recent MO question that I found a good MO question, while it seems not for writing an article (it in principle could be, but it seems not in the present case):

http://mathoverflow.net/questions/110345/does-a-power-series-converging-everywhere-on-its-circle-of-convergence-define-a-c

There is a clear mathematical question OP found interesting enough to dedicate some time to look (before asking) for an answer. This was unsuccessfull so one asks on MO. IMO this is a very good way to use MO.

AMS conference list RSS feed

2012-08-25T11:03:22-07:00

Hi,

I am wondering if anyone knows how to use the ams mathematics calender(http://www.ams.org/meetings/calendar/mathcal) as an RSS feed? I wanted to ask on MO, but I don't really think it is an appropriate question, so I thought I could put it here instead.

Ideally, any time this calender updates, I would get the update as an RSS story. If anyone knows how to pull something like this off, I would be very appreciative.

Thanks! -Bryan

Looking for an answer on an old question without a satisfactory answer

2012-08-22T22:59:06-07:00

I'm curious to hear an answer to http://mathoverflow.net/questions/3910/primary-decomposition-for-modules. So far, two people have posted, both giving opposite answers, and there's been no conclusion. One answer has more up-votes, but I'm leaning on the second answer. The question is in some sense a yes-or-no question: which definition is the right one?

My sense is that few people have looked at this question and that IF more people, especially experts, looked at it, one answer would clearly emerge as the correct one.

Am I missing something, or is there no way to bump a question back?

Please get this joke to its punchline

2012-08-21T15:04:43-07:00

I know this is really random, but would someone with >=3000 rep please supply the fifth (and final) "close" vote for the sandbox question

http://dev.mathoverflow.stackexchange.com/q/103749/5094

? [Note: this question is in the MO 2.0 sandbox--not the actual site, where I would not have the nerve to ask it.]

Retagged the "Riemmanian-geometry" (sic)

2012-08-17T07:31:38-07:00

Hi all,

Sorry for bumping up 4 questions. In the midst of browsing, I noticed that there's a Riemannian-geometry tag *as well as* a misspelled Riemmanian-geometry tag, with only 4 questions. I couldn't resist cleaning that up. That spelling mistake is one of my pet peeves, even if I used to be guilty of it in my younger days.

Spiro

arXiv tags (was: CS arXiv tags)

2012-06-01T11:33:34-07:00

While cleaning up tags, I noticed that we could make better use of some computer science arXiv categories to supplement the math arXiv tags that we already use.

The most relevant categories appear to be the following:

cs.CC - Computational Complexity - Covers models of computation, complexity classes, structural complexity, complexity tradeoffs, upper and lower bounds. Roughly includes material in ACM Subject Classes F.1 (computation by abstract devices), F.2.3 (tradeoffs among complexity measures), and F.4.3 (formal languages), although some material in formal languages may be more appropriate for Logic in Computer Science. Some material in F.2.1 and F.2.2, may also be appropriate here, but is more likely to have Data Structures and Algorithms as the primary subject area.
cs.CG - Computational Geometry - Roughly includes material in ACM Subject Classes I.3.5 and F.2.2.
cs.GT - Computer Science and Game Theory - Covers all theoretical and applied aspects at the intersection of computer science and game theory, including work in mechanism design, learning in games (which may overlap with Learning), foundations of agent modeling in games (which may overlap with Multiagent systems), coordination, specification and formal methods for non-cooperative computational environments. The area also deals with applications of game theory to areas such as electronic commerce.
cs.CR - Cryptography and Security - Covers all areas of cryptography and security including authentication, public key cryptosytems, proof-carrying code, etc. Roughly includes material in ACM Subject Classes D.4.6 and E.3.
cs.DS - Data Structures and Algorithms - Covers data structures and analysis of algorithms. Roughly includes material in ACM Subject Classes E.1, E.2, F.2.1, and F.2.2.
cs.DM - Discrete Mathematics - Covers combinatorics, graph theory, applications of probability. Roughly includes material in ACM Subject Classes G.2 and G.3.
cs.FL - Formal Languages and Automata Theory - Covers automata theory, formal language theory, grammars, and combinatorics on words. This roughly corresponds to ACM Subject Classes F.1.1, and F.4.3. Papers dealing with computational complexity should go to cs.CC; papers dealing with logic should go to cs.LO.
cs.IT - Information Theory - Covers theoretical and experimental aspects of information theory and coding. Includes material in ACM Subject Class E.4 and intersects with H.1.1.
cs.LG - Learning - Covers machine learning and computational (PAC) learning. Roughly includes material in ACM Subject Class I.2.6.
cs.LO - Logic in Computer Science - Covers all aspects of logic in computer science, including finite model theory, logics of programs, modal logic, and program verification. Programming language semantics should have Programming Languages as the primary subject area. Roughly includes material in ACM Subject Classes D.2.4, F.3.1, F.4.0, F.4.1, and F.4.2; some material in F.4.3 (formal languages) may also be appropriate here, although Computational Complexity is typically the more appropriate subject area.
cs.MS - Mathematical Software - Roughly includes material in ACM Subject Class G.4.
cs.NA - Numerical Analysis - Roughly includes material in ACM Subject Class G.1.
cs.SC - Symbolic Computation - Roughly includes material in ACM Subject Class I.1.

The categories cs.AI, cs.CL, cs.CE, cs.PL could be relevant to mathematics, but we don't seem to have a significant number of MO questions in these categories.

[...]

What is the average premium for giving the first answer?

2012-07-18T21:22:35-07:00

I noticed that the early answers tend to be at the top and therefore obtain more MO points. Has anyone tried to estimate the premium for answering early?

What is the probability distribution of "reputation" ?

2012-07-03T01:24:31-07:00

Just curiosity. Is it gaussian ? Or we have "heavy tail" (Joel David Hamkins, David Speyer) ?
(Probably it is worth to cut down users with very small reputation (<12) we will rest with 33% of users,
see http://mathoverflow.net/users?page=169 )
Only 4% of users has reputation more than 1000 - see http://mathoverflow.net/users?page=20 )
1% more than 5000 http://mathoverflow.net/users?page=5 )

Probably Guassian is bad idea, may be uniform is better ?
User reputation depends on 1) entrance time 2) "activity/quality" (roughly speaking reputation earned per day).
Probably 2) distributed by Gaussian, but 1) probably uniform - may be the same amount of new users appear every "month".
If 2) is Gaussian with small sigma, and 1) is uniform, then in total we get uniform distribution

Voting on answers to large CW questions

2012-07-08T14:38:07-07:00

I've noticed, in looking at many "big-list" questions marked CW (community wiki), as well as other similar questions, that some of the best answers appear at the end. I believe this is because the system causes the number of up-votes an answer gets to be dependent at least as much on how early it is posted as on its quality. I believe this for the following reason:

Answers are ordered by how many up-votes that answer has. Answers posted later (i.e. once a few good answers already have a number of up-votes) are seen by much fewer people, since few people actually scroll to the second page or even to the bottom. When an answer is seen by more people, it will, on average, get more up-votes, regardless of how good it is. If an answer is near the bottom, few people will see it, so even if everyone who sees it decides to up-vote it, it will still get few up-votes. I don't mean to say that really bad answers get up-voted. I just mean to say that any answer above a certain threshold of quality will get up-voted early-on if it gets posted early. Then, because that answer is already at the top, it will get even more up-votes in a kind of exponential pattern.

Yes, you might think this happens if an answer is posted weeks or months later. But even after a day or two, there are usually already enough answers with many up-votes that a very good answer posted then will get many fewer up-votes that an answer that is still good but not necessarily quite as good.

The result is that in threads like this with many answers, the number of up-votes that a post gets is much more dependent on when it is posted than how good it is. This is true *even* if "when it is posted" is referring to time margins of only a couple days.

I apologize, first of all, if this has been discussed, as I don't frequent the meta.

Second of all, I don't really have a good solution, and I recognize this is a difficult issue to solve. I decided to post this simply because I would like to begin a discussion. That being said, here are a few rough ideas for solutions. I say *rough* since many of them have cons, and some of them are quite wild. Feel free to post a variation on any of these ideas, or suggest a totally different idea.

* Order posts on CW questions using a combination of number of votes and recentness
* Prevent voting on questions for the first 2-3 days
* Do the same as above, but only if the question is marked "CW" AND has the "big-list" tag
* Have "random" sorting of questions for the first 2-3 days
* Some variation combining the above
* A user with some amount (say, 2000+) of reputation has the option to "bump" an answer to the top, or to the first page, for a day
* A user can bump their answer in exchange for some amount of reputation. If the answer gets a lot of votes within a certain amount of time (showing that the answer was actually good and was neglected because of how deep it was), that user regains the reputation.

A Strange welcome observed ( Is it spam ? )

2012-06-27T09:55:54-07:00

I have joined MO yesterday. As soon as I have joined MO, I read the guidelines and accordingly posted this question. As soon as I have posted the question, I received a strange comment from someone called "quid". He seems that he has met me here and then there was initially 1-mark besides his comment ( Later on I came to know that its called " Upvote" ).

As the days passed , the up-votes increased and now the count turned to be 8. I then started worrying that my account has been hacked or there is some spam message. I generally receive such sort of spam messages in yahoo, where some unknown person claims that he knows me and then speaks as if he has seen me. Later on he posts some advertisement related to his company. Moreover evidently quid doesn't has kept any details on his member page.

I hope "quid" is not of that sort. Can I take it for granted. Can I hope for a moderator to step-in into this issue and settle it ?.

Thank you. I hope my account is safe.

On my posts

2010-01-20T20:54:05-08:00

[Edit by Anton: see the comment thread to this question for background]

@Pete Wow... Pete you have pushed me into a "limbo"... I dont want to give a long reply... But it seems i have no other choice...

I dont want to discuss any personal thing here, but I would like you to know, that I work from home, and am not a professional math. student... But I am a computer science grad and we have had several math papers as subjects of study... I am about to take math, but I am doubtful, because academics dont let you think out of the box... which is why I have delayed taking the course... I want to explore math but I don't believe in mathematical rigor when I am exploring (Chaitin's fan you may say)...

Regarding your comments:

(i) I am new to MO... as such I read the faqs, and accepted wherever I think the answer's correct... Is there something else I need to do (I mean click tick marks, etc.) ?

(ii) I have done lots of mistakes, and I acknowledge that and have acknowledged that before also... thats is why I have 7 versions of a paper to arxiv... I will even withdraw my paper if someone points out where I am wrong... But when the academic community grips you like this and tells me to master something and pointing out that I need to give attention, I feel a bit intimidated... Because thats exactly what I want to do...

All I want to know is what is true... and when discussions turn into a flame game, I really hate that... because that delays knowledge exchange...

Research paper publication using mathoverflow

2012-06-21T05:58:04-07:00

I realized that there are a number of eminent research scholars, Professors and Mathematicians active on mathoverflow. Many of them are endorser for Arxiv and many are editors of reputed mathematics journals. Also there is a crowd of researchers and students who ask new questions, discuss new theories and are interested in publishing their works in journals/Arxiv but unable to do so due to lack of information or guidance.

My questions are- (1) Is it not possible to add a TAG namely "discuss research"/"help research" or something like that so that researchers can discuss their research problems with these editors/mathematicians? OR under some existing tags is it not possible to help people submit their research work to suitable journals. After discussion these editors can ask the researcher to submit their research work to them or to their journals. (2) Is it not possible for the people who can endorse for Arxiv to help new people in submitting their work to Arxiv?

Small privacy issue

2012-05-16T09:59:10-07:00

Can moderators or power user of MO knows mine IP and geographicals locatione?
Who can and who cannots?
power user: users beyond some reputution points

Open ID

2012-05-13T15:41:19-07:00

Hi,

This is my first time in meta so I hope this question is acceptable.

Is there anyway to login to mathoverflow without having to login to gmail as well? Or even is there a way to simultaneously logout of both at the same time? I ask because sometimes I logout of mathoverflow but forget to logout of gmail. I've been lucky enough to be using my own computer when that happens so far though.

Thanks
Eugene

MathOverflow user

2010-11-17T19:27:11-08:00

What's with the MathOverflow user these days? It seems to be pushing up the main page lots of old questions...

Delete backlog

2012-04-17T01:54:52-07:00

Small note, but there appears to be a large collection of old, closed posts in the delete queue with two votes to delete.

They don't appear in the default 2-day queue, you have to click on the 30-day queue to see them.

Halmos measure theory

2012-03-26T08:26:20-07:00

We seem to have a chain reaction of 7 or 8 consecutive posts on the same topic getting closed and/or flagged as spam.

Link rot: Springer EOM

2011-12-01T01:43:05-08:00

Just a headsup for everyone.

I woke up this morning to find Springer changing their model for their Encyclopedia of Mathematics and in the process breaking all existing links to eom.springer.com.

I know quite a few of us (semi-)regularly cite the Springer EOM for definitions and what-nots in posts and comments (yours truly included). This move most likely has caused some severe breakage to the readability of some posts. (And with comments not editable....)

The problem is that the original Springer EOM pages had different naming scheme at the level of the URL, so I suspect it is not quite possible for Anton to just do a glob on the database and replace the links to their new names (it would probably require a bit of hacking up a perl script and a copy of the complete index of the original EOM).

So in the event that Springer does not realise what they've done and repaired the links, we as a community will probably need to keep an eye out for old, broken, EOM links and replace them with new ones.

Gowers blog post

2011-10-31T12:10:54-07:00

In case you don't follow Tim Gowers' blog, the latest post talks about MO quite a bit, among other interesting things...

MathOverflow will be down for maintenance at some point

2011-12-01T14:10:11-08:00

MO will be moving to a new server tomorrow afternoon. This should incur no more than 10-20 minutes of downtime.

edit: Original post above, but it actually looks like the move to new servers will be delayed.

What is my situation now

2012-02-09T04:30:57-08:00

I am very sorry to disturb everyone here, with this. But I need to ask this thing, its well known that I have been banned from MO repeatedly. That's Ok. But is there any specific reason for that ?

Its true that I was completely ignorant at the beginning, but now I have followed everyone's advice here, and kept on reading some basic things instead of directly going into the higher level concepts and I was sincere in doing that ( and also successful ) . I have been learning Algebraic-Number-Theory, and Algebraic-Geometry and a bit of topology and other things. But I am getting some doubts that are really good. But the main point is that, Now-a-days I am able to understand the jargons one use in mathematics, but can't grasp the concept completely without others intervention ( in the form of providing references ) . Its true that everyone once or the other time might had an intervention ( help ) from some professor or teacher in their life. But as I don't have such facility. That's why I am depending upon these MO and Math.SE , but that made everyone take advantage over me and suppress me. Even though I have completely improved my formatting skills, and level of asking questions, every-body is deliberately down-voting my questions without any reasons. And I have also learnt the basic things and some graduate things, and I am able to post some questions in graduate level . So what is the problem with me now ? Is it true that major people try to suppress others ? , but according to my situation, I always observe an undiminished truth in that statement.

So I demand an explanation from moderators, who have banned me from entering MO. I have all sorts of answers with me, as I have followed the advises sincerely . I have read some basic things concretely and also some graduate texts before putting forward such questions. So what is the problem with me ? .

P.S : And recently I have asked a question at Math.SE which is here . After waiting for a long time, and after offering some bounty, I got an answer. So what the thing I wanted to tell is that, the proportion of mathematicians present at Math.SE are less than the ones present here. Even if I receive some answer , it would be very short ( as great mathematicians , wont find time in writing up entire detailed answer , but there are some exceptional cases present, like Prof.Emerton took much time in answering questions in a very long and detailed manner, which can be seen here . But I am very unfortunate that, now-a-days he has become very busy in his work, that he is not active at these web-sites. And its not fair on my part to just ask for a complete explanation, as he already have remarked that one should try for the maximum extent before writing up questions here. And I have merely done the same, I have read the book he suggested ( Arithmetic of Elliptic curves by Silverman ) . But I was very happy to find a person like that and I am thankful to him.

I always repeat that world always helps the persons after proving themselves in giving prizes and fellowships etc.. But no one in this world helps at the time of building one's career, the true recognition is to help the one's at the time of building their career, rather than honoring them after they became successful. As there wont be any meaning for that honor, as a lighted candle never needs a match stick. ( don't counter-argue that what is the situation if the flame turns-off, I just said for comparison ) .

Sometimes I feel like ending my life, after seeing the situation in this world, but later I learnt that its nature's law that one need to strive hard before proving something, and always world enjoys that. Anyway I dedicate my thanks to all those ( Prof.Emerton, Prof.Pete.L.Clark.. ) who offered an unparalleled service in helping thousands of students through their pure service, though I believe, consists merely of “tanquam folium a vento rapitur et quasi scintilla in arundinete” (leaves caught by the wind, sparks in the brush wood) with great respect to all those who have inspired me.

Thank you.

Why was this question closed ?

2012-02-09T02:01:04-08:00

I fail to understand why this question was closed ? http://mathoverflow.net/questions/87647/connections-of-results-in-harmonic-analysis-in-the-theory-of-transcendental-numbe . It seems to me a little extreme. Is it because those voted are sure, that the results in harmonic Analysis has no bearing to Transcendental Number Theory ?

The initial title was asking for connection with Uncertainty Principle, which I changed later as per S. Carnahan's suggestion. I also added what led me to think that there might be connection to results in Harmonic Analysis :-

That Polya's result about entire function of exponential type, having slow growth (i.e., type < log 2 and taking integer values at integers have to be polynomial can be seen as a Uncertainty type result.

If someone could elaborate on what I am missing I would be very thankful.

How could Mathoverflow be made easier to browse?

2011-12-23T10:51:08-08:00

Now that MO has been around for 2.25 years or so, it has a large amount of content in the form of questions and answers. The search features work reasonably well, so if I have a question that's been asked before, it is usually easy to find.

However, when using the website to browse in general (as opposed to search for a very specific question), I personally find that there is too much focus on the most recent questions and answers and not enough on the very best questions and answers of all time. This has its plus points, but I see a big minus. It's very hard to get a general feel for a topic within mathematics simply by browsing through the list of questions asked within that topic. I think this problem could get worse with time because some of the very best and most fundamental questions within each topic were asked in the early days of Mathoverflow, and these become less and less prominent as more new content flows in.

I think this is a general feature of StackExchange-based sites. Other Q&A sites, such as Quora, seem (to me) to do a better job of surfacing good content from all time and have a better browsing experience; on the other hand, they don't do that good a job in terms of getting questions answered quickly and precisely.

I'm curious if others agree with my assessment and what ideas people have on making the site easier to browse.

Policy for deleting (as opposed to closing) questions

2011-12-21T09:23:37-08:00

[In response to a suggestion by quid, I am starting a new thread for a topic that came up in this thread. ]

There has recently been a suggestion to delete (erase from the site; make invisible and inaccessible) the "colorful language" thread. I think this is a very bad idea. I propose that MO have a policy of not deleting any questions which have had significant answers or comments.

Mathematics and Sign Language

2011-12-21T20:56:50-08:00

Resources in this area is sparse. Although the following links spells out elementary concepts and signs

http://www.youtube.com/watch?v=xmqeZLHpdTc
http://www.tsdvideo.org/index.php?lvl=9

I am curious as to if there are proofs in form of sign language. Sign language literally adds a new dimension and even if one is not handicapped, a student can understand the flow of thought in a visual way and may enhance elementary mathematics education. Additionally, I suspect advanced college level mathematics has not been translated in sign language.

Any thoughts, resources or further guidance to research in this particular area would be very much appreciated.

The Best Humor of MathOverflow?

2011-12-17T09:50:40-08:00

I'm not much of a contributor to MathOverflow, but I do love to check in and read the different postings. But one thing that is awesome about MathOverflow that I have never heard talked up before is the amazing display of humor I see here. Would anyone be interested in a side project of compiling The Best Humor of MathOverflow? I will understand if others find my request impertinent. On the other hand I would understand if some of the responses to this question were somewhat humorous themselves.

Deleting closed questions

2010-08-04T16:39:01-07:00

Lots of questions get closed, yet they linger for ever. This is of little significance, except when one searches for something.

May we consider the practice of not only closing questions (I have in mind those which are not of the contentious type...) but also actually delete them?

New stackexchange proposal -- puzzle solving and design

2011-11-22T05:57:29-08:00

I know that several of us -- hi Noah! -- are pretty interested in this topic and are capable of wasting hours discussing it on the internet. So you might be interested in getting in on the private beta for a stackexchange site on the topic. http://area51.stackexchange.com/proposals/16410/puzzling?referrer=NzVeMlNv2lkdOF2mmBha2Q2

What time of day we have the largest number of people accessing the site?

2011-11-01T17:21:42-07:00

I would like to know the best hour (when we have more people accessing the site) of day to ask my questions.

Contribution to linguistic corpora

2010-10-30T01:22:01-07:00

As perhaps most of you know, a number of linguistic corpora are under construction at various institutions. For the sake of focus, let’s consider the American National Corpus (ANC).

The ANC is soliciting contributions of contemporary English, and so I was wondering if there were some painless (=fast and easy) way for MO to make such a contribution.

The ANC has specific instruction about how to go about making such a contibution. Here’s the link:

http://www.americannationalcorpus.org/

site down at 4:31 GMT OCT 20th?

2011-10-20T09:32:24-07:00

I'm able to see meta, but no hope on the main site, is it down?

Forum features

2011-10-05T01:35:55-07:00

Regarding the recent revival of the tetration thread, there is a plugin available for this forum which automatically closes threads after a certain period of inactivity. They can be reopened if a moderator wants to do so. I thought this might be useful, and thought it might be useful for others to know of its existence so that Scott can gauge whether there's enough support to consider installing it. (Hope that's okay, Scott!)

Of course, someone can simply open a new thread on an old topic, but that's a little more effort so makes it unlikely that a "random passerby" will do so. Moreover, if someone does want to post something legitimate on an old thread, it would be better to start a new thread, summarising some key points from the old one, and thus we don't have to re-read the whole of the old thread to get an idea of what the new posting is about.

However, there may be objections that I've overlooked and so if anyone spots them, best to record them here so that if Scott likes the idea, he has all the information necessary.

(I make no presumption that Scott will like this idea, I haven't contacted him about it.)

Minimum reputation for asking a question?

2011-09-20T09:12:28-07:00

Has it ever been considered to require a very low reputation threshold (say, 2) for asking a question? Achieving this would be no problem for any reasonable user, but it would probably drastically reduce the number of off-topic questions since any new user would actually have to find out what this site is about (and at least contribute something before she chooses to ignore the rules and ask an off-topic question anyway).

Do we really need a separate "textbook-recommendation" tag?

2011-06-27T19:22:16-07:00

I ask because I've only just noticed a few questions to which the tag has been newly applied, and I don't really see why the old "books" tag wasn't enough.

MathJax

2009-12-16T16:31:07-08:00

This may be old hat to some here, but it's news to me: The successor of jsmath is on its way. Apparently, MatSciNet will be using it. Hopefully, it will be sufficiently compatible with jsmath that MO can just substitute one for the other when it's ready. But it might be worth keeping an eye on it in order to not make the transition harder.

MO in the news (broadly speaking)

2011-08-15T10:45:31-07:00

Since there's no official MO blog to collect such information, I hope it's ok to make a note here.

In case you haven't followed the nymwars surrounding Google+ and its clear name policy, one byproduct is a site called my.nameis.me with testimonials for online anonymity.

On that site there's a very good post by Grant Olney Passmore about MO as a good example.

Comment clean-up

2011-07-13T14:21:50-07:00

At WillieWong's request, I'm cleaning up (i.e. deleting) the comments on http://mathoverflow.net/questions/69589/carlesons-theorem-on-the-adeles-and-other-exotic-groups, as they all refer to a previous incarnation of the question which has been significantly rewritten. I'm dumping the deleted comments here for reference.

Please see mathoverflow.net/howtoask – David Roberts Jul 6 at 4:35

David: Is this question inappropriate? Is asking for references more answerable? – Taylor Dupuy Jul 6 at 6:29
2

No, I meant phrasing the question(s) with a little more padding/explanation/motivation. The content of the question is fine, and indeed I think it might receive more attention if not written just as a block of text. – David Roberts Jul 6 at 7:27
1

Taylor, when you say "where can I find a proof for nonabelian compact groups", does that mean you know the result is true for nonabelian compact groups? or is that part of your question? – Yemon Choi Jul 6 at 16:16

Yemon: The validity is part of my question: Is it true that for every f in Lp(G) that fˆ in Lp(Gˆ). I can't find a reference but that doesn't necessarily mean it isn't true. – Taylor Dupuy Jul 7 at 9:35

I removed this part from the post: In interested in the following questions: - Does there exists some type of Calderon-Zymund decomposition for f in L^1(G) when G is a locally compact topological group? - What are some references for Calderon-Zygmund theory over locally compact topological groups? – Taylor Dupuy Jul 7 at 9:47 1

@Dupuy: Could you please clarify what you mean by Fourier transform of a function on a non-abelian group (for example, the symmetric group Sn)? Thanks! – SGP Jul 7 at 11:52
3

Taylor, you should seriously edit your question : Fourier transform is not continuous from Lp(Rn) to itself if p≠2. Instead, it sends Lp to Lq if p∈[1,2] (as usual 1/p+1/q=1) by Hausdorff-Young inequality, and Lp outside L1loc if p>2. Also, you should precise what you mean by Calderon-Zygmund decomposition. – BS Jul 7 at 12:13
1

Taylor, do you mean that the partial sum operator, or some associated maximal operator, is bounded from Lp to itself? If so, that is not, repeat NOT, what you wrote... – Yemon Choi Jul 7 at 16:11

Willie: Uh, thanks for the insightful comment, derp. SGP: en.wikipedia.org/wiki/… BS: en.wikipedia.org/wiki/… you would need a generalization of Cubes in the general setting. Boundedness of the Fourier Transform comes from boundedness of the Hilbert Transform + properties of translating the fourier transform, and the proof I know uses a Calderon-Zygmund decomposition. Yemon: I like your bold. Lp Boundedness of the operator Cf(x)=supR>0|∫R−Re−2πixξf(x)dx| implies bddness of Fouri – Taylor Dupuy Jul 8 at 6:42

I vote against closing. We should let the OP an opportunity to edit and clarify his question. – Gil Kalai Jul 8 at 8:55

Yemon and BS: That was a really silly and embarrasing mistake of me and I made an edit once I made the mistake that was still wrong. Forgive me for not seeing this right away. – Taylor Dupuy Jul 8 at 13:59
1

Gil and Other: The question should have been about a Carleson operator (which I messed up the statement of) and about whether it held for other groups (I'm in the process of learning harmonic analysis and wanted to know the statement in general). Is the "Carleson Operator" Strong (p,p) for locally compact abelian groups and compact nonabelian groups. I know the answer to my question is no now because of what Fefferman proved jstor.org/pss/1970864. I also know now that a statement of what a "Carleson operator" is for general groups isn't easy to straight forward. – Taylor Dupuy Jul 8 at 14:04

What should I do with this one? Should I rephrase the question in a new post? I'm not exactly sure what your guys policy is since I botched this up pretty badly. – Taylor Dupuy Jul 8 at 14:06 1

I think underneath there is a good question in there. I used the answer page instead of the comment spot because I don't have enough space in the comments to clearly write down the argument. What you should do now, is, I think, edit your question to the correct form (the one about Carleson operators), because when you started asking the question you didn't know the result. Then you can post an answer yourself stating that you've actually found out about Fefferman's paper on ball multiplier, after you've formulated the question. – Willie Wong Jul 8 at 14:53

Stats on publishing and citing

2011-03-31T18:04:12-07:00

Let me abuse meta.MO a bit.

In the context of some discussions we are having at my university, it has become evident that some statistical information regarding publishing practices in mathematics would be necessary to proceed---you know, facts. In particular, I would be immensely happy to know if there are measurable and measured differences in the number of papers published by people working in different areas (think PDEs v. Algebraic Geometry v. Number theory v. Combinatorics; top level MSC groups, say); if there are measurable and measured differences in the number of citations gotten by papers in each area; and so on. Google has pointed to studies in which such comparisons are made between different disciplines (mathematics v. chemistry, say) but not at all between areas of mathematics.

Can anyone point to such information?

(I would love to get hold of MathSciNet's raw tables to compute such things... I doubt that is accessible, though)

I ask this here because I suspect the subject interests a few of the meta.MO regulars, who might help me; I don't think the question is MO material (although I believe it is relevant to mathematicians!)

Study and Collaboration Groups

2011-06-05T19:54:25-07:00

MathOverFlow is a great community of active researchers who are much willing to collaborate and think with other people. I was wondering if there was anyway one could allow this amazing collection of people to form study groups or collaboration groups through the adding of a new feature that allows one to post a suggestion for a study group or a collaboration group. That would much help especially the young researchers get together and exchange ideas.

Four closely related questions -- how best to group them?

2011-04-12T09:26:01-07:00

I'm preparing to ask, at MO, either (a) four closely related small questions, or (b) one large four-part question, or, most likely, (c) something intermediate between (a) and (b). I'm seeking feedback on how best to group the questions. They are:

(1) What's a good reference/citation for the cohomology of the Eilenberg-MacLane space $K(G, 2)$? (I'm really just interested in the degree five-or-less cohomology. Recall that $\pi_i(K(G, 2)) = G$ if $i=2$ and is trivial otherwise.)

(2) What's a good reference/citation for explicit constructions of $K(G, 2)$?

(3) The finite cell complex $X$ (details omitted here) has $\pi_2 = G$. Is there a reference for the 4- and 5-cells one needs to add to $X$ to make it into a $K(G, 2)$? (Of course one also needs to add higher cells, but I'm not interested in those.)

(4) The finite cell complex $Y$ (details omitted here; not the same as $X$ above) has $\pi_2 = G$. Is there a reference for the 4- and 5-cells one needs to add to $Y$ to make it into a $K(G, 2)$?

My first thought was to let (1) be a stand-alone question and lump (2), (3) and (4) together. But if there's a consensus here in favor of some other way of grouping them then I'm happy to follow that.

should there be a 'corner' for discussion close to mo

2011-03-31T17:27:00-07:00

This is a question prompted by the recent 'lament'-incident and similar things; I thought about the subject described below for a while already on other occassions but did not really think it through.
(I never got to read the 'lament' post, as when it was visible, I had no time, and then it was already gone;
I say this not as a complaint of any form, merely to point out that this question has nothing to do with the specific content of this 'question' that is, as said, unknown to me)

My question is essentially in the subject line, I repeat it in expanded form:

Should there (and if so, can there) be a place for 'discussiony subjects' linked to MathOverflow?

First, I stress that I really mean 'linked to' or 'close to' and not 'on'. This is not at all about advocating to relax the policy of MO, in some sense the outcome could be the contrary. It is amply documented that a significant subset of the community does not want this type of content on MO-main and I think even somebody who actually would like to have it, would, looking at some of the somewhat discussiony existing questions, arrive at the conclusion that the site, on a technical level, is (by design) not well suited for discussions. So, certainly not 'on'.

Second, the 'can there' part (if the answer to this is no, the rest is essentially obsolete).
What could I (somewhat naively) imagine: There is already a forum/discussion board prominently linked to from MO-main. This one. So, could there be a second one? This is not clear to me, but also not impossible, as my understanding (possibly flawed) is that MO-meta is not part of the software that nobody here can change, and adding an additional link on MO-main might also be feasible. It is also not clear to me, not even roughly, how much work it is to set up such a forum (for somebody who knows how to do something like this). Another option would be to allow discussion on MO-meta, however I do not think this would be a good idea, as it raises the issue that somebody who is an intense user of MO-main might need/want to follow the MO-meta but only for actual MO-meta content and not general math-related discussions. (A strict tagging could partial remedy this, but then things like this tend not to work sufficiently well to be satisfactory.)

Third, the 'should there' be part. Actually, I don't know, but perhaps yes, this is my main question. I can see pros and cons. The main points in favour of it: if this existed, it seems much easier to get rid of that type of content on MO-main. Second, and more importantly, I know of no other place than MO where there is such a large and quite diverse community of mathematicians gathered on one site. To duplicate this from scratch seems difficult (to say the least). Moreover, mathematicians seem to like to organize the 'softer' and more 'discussony' parts around more serious mathematical content (just think of all the birthday-conferences). So, basically what I envision could be the analog of the hallway at a math-conference: evidently general discussions in the lecture-room during a talk must not happen, but then a conference without any opportunity for general discussions might not be the best conference.

Since this post is already long (thanks for reading, if you made it until here), I will omit to discuss my own objections to the idea, and leave this to others.

MO mentioned prominently (Abel prize)

2011-03-23T04:46:23-07:00

In the official description of the work of Milnor (Abel prize 2011), on the Abel-prize site written by Gowers, a comment made on Mathoverflow is mentioned (top of page 2), text here http://www.abelprisen.no/nedlastning/2011/gowers.pdf

Sorry, to those who consider this off-topic (not sure what the standards are on meta), but then perhaps some people don't know yet and find it ineteresting.

A function in Stackexchange but not in MO

2011-02-17T22:17:11-08:00

I have noticed that SE possesses a function that reminds you how many days it has been for you to visit the site, why doesn't MO possess this?
Thanks.

Crazy points transfer

2011-02-12T00:48:50-08:00

User MO Scribe just somehow managed to transfer 500 points to me. How is that even possible?

A post

2011-02-08T02:36:36-08:00

I have read a post in MO
http://mathoverflow.net/questions/48855/galois-theory-generalization-of-abels-theorem-better-version
and found a somewhat strange answer, i.e. the only answer.
The answer says that this transformation can change those two polynomials, but why is it acceptable?? It makes the leading coefficient not 1, doesn't it?
Please inform me, thank you.

Statistically "correcting" votes?

2011-01-10T07:38:09-08:00

The number of votes an MO question receives is influenced by several factors other than the intrinsic appeal of the answer to the readership. The two factors that come to mind are the timing of the answer (early answers are more likely to get more votes) and the reputation of the answerer (both MO reputation and real-world reputation). Perhaps there are other factors as well.

I'm curious as to whether there is any plausible way to "adjust" votes to "correct" for these factors. It's not immediately obvious to me how to do so, but at the same time I sort of think there might be a way.

Of course, I'm not suggesting that if someone were to come up with a proposed adjustment algorithm that we should try to implement it (even assuming that the software allowed it, which I'm sure it doesn't). However, apart from the fact that this seems to be an interesting question in its own right, it could become important one day if some kind of MO-like voting system gets implemented for, say, the mathematical literature in general as a sort of informal peer-review system, and people seriously want to know what to make of the votes.

I was tempted to make this an MO question rather than a meta question, but I chose to follow Linus's example.

Repeated incorrect and argumentative comments

2011-01-04T17:28:59-08:00

The user T has made about 20 comments on the answers to http://mathoverflow.net/questions/17960/google-question-in-a-country-in-which-people-only-want-boys . At least the last few are repetitions of incorrect statements which have been refuted in earlier comments (in fact, months earlier). This is not the behavior I expect from mathematicians. I don't see a better way to respond, so I have started to flag these as spam. I would appreciate some moderator attention to this issue.

There have been some nice related results in the comments on Steven Landsburg's blog, but if they are added as comments they will be hidden below T's repeated incorrect assertions. For example, someone proved that E[G/(G+B-1)]=1/2 (for k>1), a neat result which makes it obvious that E[G/(G+B)] is less than 1/2.

Please close this question

2011-01-02T15:15:06-08:00

I asked a question that turned out to admit a very short and simple answer, given by Qing Liu in the comments.

I don't think this question belongs on MO. Can people close it? (Following customs established in other threads, I haven't yet voted for deletion, in case the question is useful to others, but I would be happy to do so if people think it reasonable.)

Google picks

2010-12-19T16:19:26-08:00

If I google for "mathoverflow", at the moment the first result is of course mo.net, but google also presents me with a short list of subresults:

Questions
Users
The FAQ
Fundamental Examples
Charles Rezk
Favorite popular math book
Laurent Moret-Bailly
Michael Hardy

Does anyone know how google picks it picks?

Happy birthday MO

2010-09-27T23:12:21-07:00

Tuesday, September 28, MathOverflow turns one year old! I think the oldest surviving post (i.e. which wasn't me seeding tags) is this one. If you happen to be around Evans today, come to 1015 at 3pm to celebrate.

stalking

2010-12-09T16:26:25-08:00

Three simultaneous down-votes today for questions I posted are on topics so disparate as to cause me again to suspect that someone's following me around, and doing this in disregard of the questions' content. I seem to recall someone suggested there was some procedure to be followed in such cases. Is there? What is it?

Are decisions to close discussed somewhere?

2010-12-03T18:25:28-08:00

Are decisions to close a particular question discussed somewhere where they can be read by people other than moderators (if that's what they are) who close a question?

A curious series of questions

2010-11-22T18:56:55-08:00

This user has been posting a series of increasingly sophisticated questions (judging purely by the number of upvotes!). My feeling is that they are not HW, since who would assign two open problems in a week ?

However, these do feel like some kind of honors thesis or even starting point of something bigger. For example, one part of his latest question turns out to be sandwiched between two well-known conjectures, and I have not seen it raised elsewhere. It is possible but unlikely that idle curiosity leads to these group of questions.

Normally I would not think too much about this. After all, sunshine is good (or something like that, sorry English is not my native tongue). But in light of recent events I think I would post this here to see if the moderators and the community have some opinions on this matters. In particular, do we answer such questions? If so, how much should we give? What if a bigger stream of questions arrives?

As I said above, I have nothing against the OP posting these questions. They are nice, I like them and I would probably give similar answers if some graduate students emailed me those questions. What I would like to know is what the community thinks, and whether some consensus has formed over this (somewhat delicate) issue, especially since the OP is anonymous.

I would appreciate your thoughts and comments.

How are the answers to questions sorted?

2010-11-19T12:03:35-08:00

How are the answers to questions sorted? They don't seem to be sorted exactly by time of answer, or by number of votes, or even by any reasonable combination of the two.

I'm asking this because I've noticed a few questions on math.SE where it seems like one answer has gotten lots of upvotes not because it's necessarily "better" but just because it happens to have been first. (I'm not going to give links because things might change!) I'm not suggesting any sort of fix but I'm just wondering if anyone knows how this works (and if it might be different between different sites running on this software).

Publicity

2010-10-13T16:56:15-07:00

It may be that MO is not in need of publicity. The AMS Notices article may have sufficed.
But some here might be interested in what CS Theory, which is definitely in need of publicity, is doing: gathering "best questions."
http://meta.cstheory.stackexchange.com/questions/457/nominations-for-publicity-poster-at-focs

A suggestion for inappropriate questions

2010-11-15T21:46:24-08:00

Now that there are meta and math"underflow", when somebody asked a bad question (e.g. How to do this integral by parts), can we, instead of closing it, forward it to the place where we think it is proper? The one who asked such a question would also be happier for finding the right place to discuss!

Not quite definitive answers

2010-11-15T12:11:11-08:00

It would be nice to have various gradations for answers. Right now one can vote up (or down) an answer, and OP can choose an answer as the definitive one. But what should one do if the original question appears to be quite difficult but someone gives an answer that goes a long way to answering it. An example that I have in mind is http://mathoverflow.net/questions/44844/galois-groups-of-a-family-of-polynomials . The answer by Snuffleapugus (I'd really like to know who it is) makes substantial inroads into the problem but doesn't answer the original question (let alone a reasonable suggested generalization). Since it doesn't completely answer the original question I didn't want to give it a "check mark". On the other hand I feel that it deserves more credit (and being highlighted) than some of the other answers. I realize that trying to set up a more complicated system is a difficult undertaking (to decide how it should be structured). How should we deal with this?

Which graduate algebra text would you choose to keep if forced to make a choice?

2010-10-31T13:48:28-07:00

This is CLEARLY not an appropriate question for the main MO board-but it may be ok here for meta. Also,I want the input of professional mathematicians (especially the algebracists) on this question which has been a personal corundum not only for myself,but several of my fellow cash-strapped graduate students.

Suppose you have Paul Cohn's BASIC ALGEBRA;GROUPS,RINGS AND FIELDS and FURTHER ALGEBRA WITH APPLICATIONS,both volumes of Nathan Jacobson's BASIC ALGEBRA (the new Dover paperbacks),Lang's ALGEBRA and Anthony Knapp's BASIC ALGEBRA and ADVANCED ALGEBRA-and you need to sell one of the sets.

Which one would you sell? I'd like input from people familiar with all these books to give thier opinions based on both thier opinions of the books themselves and thier usefulness as texts. I'll give my opinions when I get some feedback.

personal names

2010-10-09T23:21:14-07:00

Why not respect the international non-standard of the presentation sequence of personal names? In some places, the given name comes first, and the familiy name last, but in many others, it is the reverse. So, instead of using the needlessly specific terms “first name” and “last name”, we should use “given name” and “family name” in the account information area.

Blogging capability

2010-10-30T01:41:31-07:00

Microsoft has just announced that it is phasing out its blogging feature in favor of partnering with WordPress.com to provide this functionality. If WordPress.com is all that great (which evidently it is), and that plug-and-play-able, then would it be perhaps not a lot of trouble for MO to partner with it as well, to allow for extended discussions and sharing?

Name change for MO

2010-10-29T23:22:03-07:00

I remember reading somewhere herein in meta some misgivings about the name “Mathematics Overflow”, the concern being that people surfing the web who happen to come upon this site may misundertand it (not reading the FAQ, of course) for being the kind of thing that se.math is for. There is another concern that I would like to point out: semantically “mathematics overflow” is close to “superfluous mathematics”. It may be only a question of time before this becomes genuinely embarrassing for the site.

Not to worry. Very apt alternative names exist. Here are two:

The Rabbit’s Burrow – the allusion being to the well-known joke about the wolf-eating rabbit, of course.

House for the Feeble-Minded – the allusion being to the joke/subterfuge used in Isaac Asimov’s story “Profession”, of course.

I’m not saying that there is any hurry about it. But then, there “wasn’t any hurry” about preparing for Y2K, either.

Proposal of MathOverblog on StackExchange

2010-10-20T17:08:26-07:00

http://area51.stackexchange.com/proposals/22924/mathoverblog

The idea of this MOB site is quite simple. The difference of it from MO is that MO requires genuine questions, while on MOB you can just blog (like any mathematical bloggers do). I personally see the advantage of MOB (as contrast to traditional blogs) being:
1.people can start off easily (you don't have to open a blog by yourself and maintain it regularly)
2.You can vote on interesting entries.

The potential disadvantages:
1.topics can be really off-topic. i.e., it's relatively harder to define what is a good MOB entry. (in contrast, MO nowadays has a very good standard)
2. users might not be as active as on MO.

But in any case, it's free, so I just opened the proposal. Have a try if you like. Thanks.

Mathematics search engine!

2010-09-28T07:16:29-07:00

Someone posted this on meta.math.SE as a resource. It seems pretty nifty. It lets you search the internet in TeX.

Uniquation

diploma thesis

2010-10-11T02:33:01-07:00

Currently I am working on my diploma thesis. It is about an unsolved problem in algebraic geometry / homological algebra, which I should at least approach by learning the work which has been done so far. Many of my recent questions were directly or indirectly inspired by this question and already show my ideas how to attack the problem. There is many literature about it, which I have not finished reading at all, but I think the focus is always another one.

Now I wonder if it's actually appropriate to ask that unsolved problem on mathoverflow directly. Because here on mathoverflow I can contact directly the experts who are dealing with the subject. But I wonder if this is acceptable because this is my diploma thesis and I should do all the work. I've already emailed some professors around the world (which my professor also did to learn the current status of the problem) which were very kind and gave me some references. So basically I've already started to contact other professors which take some of the work away from me. Well, and the same of course holds for my recent questions on mathoverflow, which were partially answered already.

What do you think?

MO money matters

2010-10-10T21:00:52-07:00

Ravi tells me he's applying for a large grant with a bunch of people. He wants to know if he should put MO in the buget. Here are the relevant bits of the email he sent me.

(i) As I understand it, the actual necessary costs remain $0, and will be so for the foreseeable future. If that's not true, or if some money can help at all, please let me now.

It's correct that I haven't even given SO Inc. any kind of billing information (they haven't asked for any). I've actually tried to press them a bit to take some money from us, but without success. Why do I want to pay them so much? If we pay them for the site, it's clear exactly how everybody benefits, but if they're doing us the "favor" of hosting the site for free, it's not sufficiently clear what's in it for them, so I worry that we may end up in a position where we have make a decision which does wrong by MO to repay the favor. Unfortunately, it looks like this will remain up in the air for the forseeable future.

(ii) If (i) is completely taken care of: I know that MO takes a lot of volunteer time. I'm not sure about the distribution of the back end effort (not the moderating, which should certainly be completely volunteer), so I'm going to assume for the sake of argument that it is all you. One possibility we'd like to think about is to ask for $10000/year to pay (you) for this. More precisely, we would ask for $5000 per month for 2 months in the summer (although of course the effort wouldn't be concentrated in the summer). This would reasonably combine with grad school or a postdoc.

I certainly don't object to getting paid for things I'm going to do anyway, but I want to be extra careful not to create any conflict of interest, or even the possible perception of a conflict of interest. As far as I can tell, there wouldn't be any such conflict, but this is an issue where I think community opinion is very important, so I'm bringing this question to meta.

Cons: If many people feel like introducing money spoils the intention, goals, or decision processes involved in running MO, I'd rather keep things just as they are. We have an awesome community of volunteers running MO, both as official moderators and as helpful high-rep users. I don't want these people to feel like the project has been compromised. Any decision that would reduce this kind of generous participation would be a bad one.

Another important question is whether many people feel like this would compromise my ability to make future decisions on behalf of the MO community. Perhaps this is mitigated by the fact that this money would be coming out of Ravi's grant, so he effectively becomes an oversight committee.

When migration comes up, I'd like the MO community to be united on terms of migration and the reasons for them. We've already decided that maintaining administrative access (e.g. full database dumps, control of banners, control of custom javascript) is extremely important, otherwise we would be putting too much power in the hands of a for profit company run by non-mathematicians; nice as they are, their interests could very easily part with the interests of the mathematical community. I worry that demanding administrative access might be recast as an attempt to protect a source of income.

Pros: Aside from the obvious pro of padding my buget, I like the idea of being able to allocate some money for things like stickers, t-shirts, cakes, and posters. These expenses are tiny enough that they've easily been paid out of pocket so far. One real potential benefit is that if we can convince SO Inc. to take some money in exchange for more control after migration, I could comfortably pay that out of pocket so we wouldn't have to wait for another grant application to go through.

If you have any thoughts or opinions about this stuff, please post them here. My feeling is that community opinion is the most important factor in this decision, so I'd really like to get some feedback. Ravi says he needs to get the grant together very soon (next couple of days). Hopefully that leaves enough time to hash things out an make the best decision.

User 10000

2010-10-12T13:12:19-07:00

We have just reached user no 10000.

MO is now the source of all wisdom

2010-10-01T12:51:46-07:00

From Aaronson's blog,
http://scottaaronson.com/blog/?p=466

"Look: if I really needed to know what (say) the best-regarded PhD programs in computer science were, I could post my question to a site like MathOverflow—and in the half hour before the question was closed for being off-topic, I’d get vastly more reliable answers than the ones the NRC took fifteen years and more than four million dollars to generate."

Question on de Branges contribution to RH

2010-09-12T14:07:11-07:00

http://mathoverflow.net/questions/38049/what-exactly-has-louis-de-branges-proved-about-the-riemann-hypothesis

Has a long discussion in the comments on the merits of the question which might be better placed here. It has already been closed and reopened. I originally voted to close and would do so again but I'll wait to see where the discussion goes here.

Standard practice when finding errors in a recent graduate textbook?

2010-09-09T09:54:13-07:00

What is the standard practice when finding errors in a recent graduate textbook?

The word "recent" should be read as "published less than a decade ago".

Automatic MO Bumps

2010-09-09T06:03:26-07:00

This is probably documented somewhere that I don't know about, but I was wondering what the algorithm was for deciding when the MathOverflow user auto-bumps certain questions to the top.

Not that it's at all a bad question, but I feel like we've seen http://mathoverflow.net/questions/33533/name-this-pro-p-group a disproportionately large number of times, even compared to questions with similar number of votes, favorites, and answers.

Answering after closing?

2010-09-02T20:41:09-07:00

I just saw a new answer posted to a question that had been closed for an hour:

http://mathoverflow.net/questions/37569/is-this-set-countable/37574#37574

How is this possible? If you have started typing an answer before it is closed, and it is closed while you are writing, can you still post it?

OK, as I was writing this, the answer was deleted. I'll still ask, because I'm still curious as to how this works in general, but now I guess only moderators and those with 10000 points will see the answer.

How do I get one of those nifty mathoverflow signs for my office door?

2010-08-18T14:58:31-07:00

I was walking around the ninth and tenth floors of Evans Hall at Berkeley today and saw that some people had signs with the mathoverflow logo where their names would ordinarily be.

Do you have any more? I want one.