Page **3** of **5**

### Re: Show us your articles! Or what's your Erdos number?

Posted: **Fri Mar 28, 2008 12:29 pm UTC**

by **EstLladon**

And I have a new paper that will be printed in the CSR 2008, LNCS 5010 proceedings. But I'm not sure if I can show it here. I can probably, but it is my first published thing, so I don't want to mess it up.

### Re: Show us your articles! Or what's your Erdos number?

Posted: **Fri Mar 28, 2008 5:49 pm UTC**

by **btilly**

EstLladon wrote:And I have a new paper that will be printed in the CSR 2008, LNCS 5010 proceedings. But I'm not sure if I can show it here. I can probably, but it is my first published thing, so I don't want to mess it up.

Did you sign over copyright? If so, then you have to ask them and likely can't. If not, then it should still be yours to do with as you will.

### Re: Show us your articles! Or what's your Erdos number?

Posted: **Tue Apr 15, 2008 4:43 pm UTC**

by **pkuky**

does going to a math competition on the same team as someone who's dad, who has a 1, wrote one of their slutions for them, give me a 3?

### Re: Show us your articles! Or what's your Erdos number?

Posted: **Thu Apr 24, 2008 3:30 pm UTC**

by **CFC**

This seems like an introduction thread (or something like one). My daughter pointed out a xkcd comic (

http://xkcd.com/410/) and I decided to "join" xkcd because it looks interesting.

About myself:

MR Erdos Number = 3

Putnam Exam: 1972 - 5 points; 1974 - 25 points

(High School - 1972) BA - 1975, PhD - 1981

A few papers (35?) including one Math Reviews Featured Review. (Look on MathSciNet for the exact number.)

A website on one of my research interests:

http://156.26.12.23/LAS08.htmlPS I guess I have to be on my best behavior here. However I find the use of "British English" to be rather silly. I love London, Edinburgh, etc. (but prefer Leipzig, Pisa, etc.

)

### Re: Show us your articles! Or what's your Erdos number?

Posted: **Fri May 02, 2008 1:56 am UTC**

by **marginally_stable**

Not a pure math paper (more of math applied to trajectory planning), but I was bored and wanted to procrastinate from preparing for a math exam.

### Re: Show us your articles! Or what's your Erdos number?

Posted: **Fri May 02, 2008 4:35 am UTC**

by **pnevma**

Uhg... now I have to read all these papers... as if my "papers to read" directory weren't big enough...

On a related note, I have (at least) 3 professors with Erdös numbers of 2... I really think it's hard to have an Erdös number higher than 3 if you do really any serious modern discrete research... There just isn't anything being done that Erdös didn't help start.

### Re: Show us your articles! Or what's your Erdos number?

Posted: **Sat May 17, 2008 12:29 am UTC**

by **skeptical scientist**

I just submitted my first article to the Journal of Symbolic Logic for review. With some luck, I will soon be a published mathematician!

Unfortunately no co-authors, so no Erdös number yet.

### Re: Show us your articles! Or what's your Erdos number?

Posted: **Sun Jun 15, 2008 12:33 pm UTC**

by **EstLladon**

Finally saw my name in print

here.

Now for only 25$ you can read my article. What a nonsense. You can write me instead. If you are really interested.

It is proceedings of

this conference.

When I was giving a talk about my paper on the conference I was wearing my Useless t-short. I think I was the first ever to give a talk on a math conference wearing an xkcd t-shirt. Am I right?

### Re: Show us your articles! Or what's your Erdos number?

Posted: **Fri Aug 01, 2008 3:28 am UTC**

by **mandariehl**

Ok, I'll bite. Since I haven't seen anyone post yet with a confirmed (not hopefully in the future) 2, that's me. It was even long enough ago that I am listed on the Erdos2 list.

I am also friends with lots of 2's, and not only have I taken classes with Fan Chung Graham (who Erdos lived with for awhile and published many papers with), both Fan and Ron Graham were on my dissertation committee.

I really don't want to post any papers, because they are very specialized in a way that makes them really uninteresting for others to look at who aren't in my area.

I've never posted on here before, but I truly love xkcd.

### Re: Show us your articles! Or what's your Erdos number?

Posted: **Sat Aug 02, 2008 12:43 am UTC**

by **camipco**

Manda Riehl, you are such a babe.

Also, if anyone knows how to get Manda into a movie with Kevin Bacon, that would be super. Thanks.

### Re: Show us your articles! Or what's your Erdos number?

Posted: **Wed Aug 06, 2008 6:20 am UTC**

by **erniepan**

Er... hi. I'm an

Erdős #3, with at least sixteen Erdős #2

coauthors. I just can't seem to break that barrier!

### Re: Show us your articles! Or what's your Erdos number?

Posted: **Wed Aug 06, 2008 4:18 pm UTC**

by **pkuky**

camipco wrote:Manda Riehl, you are such a babe.

Also, if anyone knows how to get Manda into a movie with Kevin Bacon, that would be super. Thanks.

it would be evenmore awesome if kevin bacon changed his name to Chris P. Chris P. Bacon.

### Re:

Posted: **Mon Aug 11, 2008 2:22 pm UTC**

by **rpresser**

Woxor wrote:I just realized that one of my profs last year had an Erdos number of 2. I had the opportunity to proofread a book he was writing (and be credited in the published version for as much), but I didn't do it! Curses! I don't know how close I'll get to a 3 again.

Just spend the next decade obsessively learning everything he finds interesting, and keep in contact with him. The opportunity should arise eventually.

### Re: Show us your articles! Or what's your Erdos number?

Posted: **Mon Sep 15, 2008 10:35 am UTC**

by **EstLladon**

My new article is now available at

http://tr.cs.gc.cuny.edu/tr/techreport.php?id=363 . Shorter version of it is sent to this conference

http://lfcs.info/lfcs09/ . If it is accepted I will go to Florida at the beginning of January!!!

Edit: they had messed up something and posted the short version behind that link. Well... I was going to write even longer version anyway.

### Re: Show us your articles! Or what's your Erdos number?

Posted: **Mon Dec 01, 2008 9:27 am UTC**

by **chapel**

Hi all, I've joined up here largely because of the math section. (Most other math forums are "do my homework for me" sites.) I'm currently a grad student with (countably?) infinite Erdos number, however I am currently working on my thesis which will hopefully find home in an applied journal and give me Erdos 5.

### Re: Show us your articles! Or what's your Erdos number?

Posted: **Wed Dec 10, 2008 6:45 am UTC**

by **LSN**

Ronald Graham is one of my CSE professors (and I have a final in his class this Thursday!!). But I don't have any articles or papers or anything. He did sign a faculty recommendation form for me, though. Maybe my Erdos number is 2i?

### Re: Show us your articles! Or what's your Erdos number?

Posted: **Fri Jan 23, 2009 8:40 pm UTC**

by **wisnij**

If

heavily mathematical physics papers count, then I'm #3 (Erdos -> Goldberg -> Magdon-Ismail -> me).

### Re: Show us your articles! Or what's your Erdos number?

Posted: **Wed Feb 04, 2009 3:02 am UTC**

by **urbazewski**

My Erdos # is 4, but the last link(s) is in the

IEEE Transactions on Signal Processing. The papers are: "Coordination Failure as a Source of Congestion" and "Avoiding Global Congestion Using Decentralized Adaptive Agents." Both papers derive simpled adaptive "solutions" to the El Farol problem (related to the "minority game") and show why agents who have less information and/or less sophisticated strategies can arrive at a socially optimal solution. It's not math, and it's not exactly signal processing either, but it's what I've got.

### Re: Show us your articles! Or what's your Erdos number?

Posted: **Fri Feb 13, 2009 6:16 pm UTC**

by **taby**

Seeing how the Valentine's Day comic is related to fractals...

I have a couple of fractal-related papers up now. Nothing outrageously creative, but they were extremely fun to do.

Some quaternion Julia sets using iterative functions other than [imath]Z = Z^2 + C[/imath]:

http://cavekitty.ca/fractal.pdfApproximating the disconnectedness of quaternion Julia sets using marching cubes:

http://cavekitty.ca/inv_ssa.pdf (source code:

http://qjssurfareavolume.googlecode.com ... regpu3.zip)

Erdos number does not apply. I haven't coauthored a paper. Yes, I published in Chaos, Solitons & Fractals on purpose...

### Re: Show us your articles! Or what's your Erdos number?

Posted: **Tue May 12, 2009 1:51 am UTC**

by **mastered**

I remember having heard of Erdos numbers somewhere, but... doesn't that mean you know someone who knew him, etc.? Or something to do with papers. He's still alive? Wow, I must get to work.

### Re: Show us your articles! Or what's your Erdos number?

Posted: **Tue May 12, 2009 2:18 am UTC**

by **stephentyrone**

mastered wrote:I remember having heard of Erdos numbers somewhere, but... doesn't that mean you know someone who knew him, etc.? Or something to do with papers. He's still alive? Wow, I must get to work.

Degrees of separation via co-authoring papers. i.e. if you co-authored a paper with Professor X, who co-authored a paper with Erdos, you have an Erdos number of 2.

### Re: Show us your articles! Or what's your Erdos number?

Posted: **Wed Jun 03, 2009 8:51 am UTC**

by **t0rajir0u**

mastered wrote:He's still alive?

Died in '96, so the list of people with

Erdos number 1 is now fixed (although I'm not sure if Wikipedia's list is exhaustive).

### Re: Show us your articles! Or what's your Erdos number?

Posted: **Fri Jun 19, 2009 4:48 pm UTC**

by **Carteeg_Struve**

Man, is there a massive database out there for people in the science community? I was published in 2001 in JGR (Space Physics), but I don't know the numbers of my co-authors (my professors and a satellite data-owner).

### Re: Show us your articles! Or what's your Erdos number?

Posted: **Tue Jun 30, 2009 5:00 pm UTC**

by **CrazyIvan**

Turns out my number is 4.

I'm quite content with this, considering I'm an epidemiologist, not a mathematician. My articles probably aren't terribly of interest to anyone who made it this far into the thread, except maybe for this one via general interest:

The untapped potential of virtual game worlds to shed light on real world epidemics

ET Lofgren, NH Fefferman - The Lancet Infectious Diseases, 2007

### Re: Show us your articles! Or what's your Erdos number?

Posted: **Tue Jun 30, 2009 9:18 pm UTC**

by **LordBritish**

Does the joint editorship of a conference proceeding book count as joint publication (using the weakest definition of Erdös-number)? If yes, I have a 3, otherwise it is 5 via regular papers...

### Re: Show us your articles! Or what's your Erdos number?

Posted: **Wed Jul 01, 2009 3:24 pm UTC**

by **promethean**

Do I have to have an Erdos number by virtue of being in the Math community? If so, I'm out of luck, but otherwise my Erdos number will depend on Erdos's Bacon number. I have a Bacon number of 3, by virtue of Me(3) -> Chip Bolcik(2) -> Alec Baldwin(1) -> Kevin Bacon(0). I saw in a posting about erdos-bacon numbers that Erods, in a bit of hearsay, may have a Bacon number of 3, which would put my Erdos-Bacon number at a fairly respectable 6, despite highly limited math skills.

### Re:

Posted: **Wed Jul 01, 2009 4:50 pm UTC**

by **Tacereus**

kira wrote:cmacis wrote:We have mathmos here, just not a lot past the first year of BSc.

Saw the title and knew it would make no sense to me.

Yeah, I've already got my math degree and I still didn't have to write anything but summaries of other people's papers.

Same here

### Re: Show us your articles! Or what's your Erdos number?

Posted: **Thu Aug 27, 2009 7:54 pm UTC**

by **Emanuele_85**

i found out that i have 5, since a professor i published a computer graphics article with published with another, that published with J T Schwartz who is in this list

https://files.oakland.edu/users/grossma ... rdos2.html, i wonder how common 5 is this.

### Re: Show us your articles! Or what's your Erdos number?

Posted: **Thu Sep 17, 2009 9:43 pm UTC**

by **Pers**

Mine's 5, with nine distinct PTP (Paths To Paul) that I know of.

(But them I'm a physicist with only 60 pubs to my name, so I didn't expect to be close).

### Re: Show us your articles! Or what's your Erdos number?

Posted: **Wed Sep 23, 2009 9:43 pm UTC**

by **njperrone**

I removed the pdf because it was false. Thanks for the scrutiny guys. I really do appreciate it.

### Re: Show us your articles! Or what's your Erdos number?

Posted: **Thu Sep 24, 2009 7:44 am UTC**

by **jaap**

njperrone wrote:Well, I discovered this and proved it throught the month of August 2009. It's final proof was made within the first two weeks of September. Please tell me your thoughts on this. Any and all criticism is welcome.

You do not have a proof. It breaks on functions such as:

f(x) = 1

f(x) = 1+sin(x)

f(x) = sin(pi x)

f(x) = sin(2pi x) / 2

^{x}f(x) = {sin(x) for x<0; 1+sin(x) for x>=0}

f(x) = {1 for x=1/2 ; 0 elsewhere}

Think through the reasons for why the above functions make your proof fail. Also think about this: If A implies B, it does not necessarily follow that B implies A.

### Re: Show us your articles! Or what's your Erdos number?

Posted: **Thu Sep 24, 2009 11:42 pm UTC**

by **njperrone**

jaap wrote:njperrone wrote:Well, I discovered this and proved it throught the month of August 2009. It's final proof was made within the first two weeks of September. Please tell me your thoughts on this. Any and all criticism is welcome.

You do not have a proof. It breaks on functions such as:

f(x) = 1

f(x) = 1+sin(x)

f(x) = sin(pi x)

f(x) = sin(2pi x) / 2

^{x}f(x) = {sin(x) for x<0; 1+sin(x) for x>=0}

f(x) = {1 for x=1/2 ; 0 elsewhere}

Think through the reasons for why the above functions make your proof fail. Also think about this: If A implies B, it does not necessarily follow that B implies A.

First, it does not break on f(x)=1 because d1/dx is 0 and no matter how many times you add 0 to 0 you always get 0. And sin(pi x) is still an odd function which works with my formula. you're last counterexample, f(x) = {1 for x=1/2 ; 0 elsewhere}, is non-differential over the real number line so it cannot be used with my formula; the same is true with f(x) = {sin(x) for x<0; 1+sin(x) for x>=0}. d(1+sin(x))/dy=cos(x) whose integral is sin(x)+c which has the potential to be an odd function; my formula still holds up. The only real counterexample that you have provided was 1+sin(x) and sin(2pi x) / 2

^{x}. The first one can, and will be cleared up by constraints placed onto the formula and with a more explicit definition of useage. So all you have provided was you pointing out that my explanation was not complete. Actually, sin(2pi x) / 2

^{x} can be cleared up by presenting a constraint onto the formula. Once again, all you have provided was a need to make my explanation and use of the formula more explicit. I thank you for that. Thank you very much.

Now, you would have had only one counter example had you actually understood my theorem.

### Re: Show us your articles! Or what's your Erdos number?

Posted: **Fri Sep 25, 2009 6:37 am UTC**

by **jaap**

njperrone wrote:First, it does not break on f(x)=1 because d1/dx is 0 and no matter how many times you add 0 to 0 you always get 0.

The the function f(x)=1 is neither even nor odd, despite that sum of yours being zero.

njperrone wrote:you're last counterexample, f(x) = {1 for x=1/2 ; 0 elsewhere}, is non-differential over the real number line so it cannot be used with my formula;

You didn't say in your paper it had to be differentiable everywhere. This counterexample is differentiable at every integer x.

Furthermore, instead of just changing the function at one point, you just could easily change a small section in a differentiable manner.

For example:

f(x)= { 1-cos(2pi x) for x in [0,1]; 0 elsewhere }

njperrone wrote:the same is true with f(x) = {sin(x) for x<0; 1+sin(x) for x>=0}. d(1+sin(x))/dy=cos(x) whose integral is sin(x)+c which has the potential to be an odd function; my formula still holds up.

So wait - you're formula is not testing whether a function or odd or even, only whether it has the POTENTIAL to be odd or even? Where does it say that in your paper?

Okay. Here is a new magic formula for testing whether a function is odd or even. If f(1)=f(-1) it has potential to be even, and if f(1)=-f(-1) it has potential to be odd. Your formula is really not much more use than that. It is well known that the derivative of an even function is odd (when the derivative exists) and the derivative of an odd function is even. See

wikipedia. Your sum is merely a necessary but not sufficient condition for testing whether the derivative is even/odd.

### Re: Show us your articles! Or what's your Erdos number?

Posted: **Fri Sep 25, 2009 5:00 pm UTC**

by **njperrone**

Like I said, it needs to be more explicit. I assumed that dx/dy implied a function was differential everywhere.

http://mathworld.wolfram.com/EvenFunction.html This explains an even function for you, and it includes 1 as being even. It is rather obvious.

Also, love your sarcasm. I did notice this, but thought it rather neat that I could test the symmetry of a function using summation. Sorry to not meet your intelligence standard, but an experimenter is definitely better off.

And your example, f(x)= { 1-cos(2pi x) for x in [0,1]; 0 elsewhere }, still will not work once again because it jumps at the point 1 so that the limit coming from the left is different from the limit coming from the right. A definite failure when it comes to having a derivative.

Like I said, you providing examples has made me need to go back in and make the explanation more explicit. I thought these things would be assumed, but I guess not when someone really wants to be heard. So thank you, thank you very much. It does need revision in the form of explanation.

### Re: Show us your articles! Or what's your Erdos number?

Posted: **Fri Sep 25, 2009 5:04 pm UTC**

by **njperrone**

jaap wrote:

So wait - you're formula is not testing whether a function or odd or even, only whether it has the POTENTIAL to be odd or even? Where does it say that in your paper?

On the last page, bottom of page two continuing onto 3, it explains this. It does not use the word potential, but somewhat close analysis of that observation will definitely tell you the same thing. Just without the word potential.

### Re: Show us your articles! Or what's your Erdos number?

Posted: **Fri Sep 25, 2009 5:57 pm UTC**

by **jaap**

njperrone wrote:jaap wrote:

So wait - you're formula is not testing whether a function or odd or even, only whether it has the POTENTIAL to be odd or even? Where does it say that in your paper?

On the last page, bottom of page two continuing onto 3, it explains this. It does not use the word potential, but somewhat close analysis of that observation will definitely tell you the same thing. Just without the word potential.

So you wrote up a claim, followed it by a supposed proof of that claim, and then as an afterthought state the claim isn't actually true.

Doesn't that indicate to you that you should change that false claim into a true one, and then write a correct proof of it?

### Re: Show us your articles! Or what's your Erdos number?

Posted: **Fri Sep 25, 2009 6:41 pm UTC**

by **njperrone**

No, I wrote up a claim. Proved it true. Then realised and didn't edit it properly. If you would have noticed in my previous comments I have realised what else needs to be done; put constraints on it, explicitly explain that the function must be differentiable across the real number line, and rewrite it without the premised of rhetorical statements. In otherwords, I must state all assumptions, regardless of their triviality.

### Re: Show us your articles! Or what's your Erdos number?

Posted: **Fri Sep 25, 2009 7:29 pm UTC**

by **jaap**

The claim at the start of your paper is that this formula tells you whether a function is odd or even.

In other words, that if that sum equals zero then the function is even, and that if that sum diverges then the function is odd.

It does no such thing.

If the function is even (and differentiable) then the sum will be zero. This does not mean that if the sum is zero that the function will be even.

I have already given an example of a function that is neither even nor odd that has a zero sum:

f(x) = { 1-cos(2pi x) for 0<x<1; 0 elsewhere}

A worse example, here is an odd function with a zero sum.

f(x) = { 1-cos(2pi x) for x>=0; cos(2pi x)-1 for x<0 }

If a function is odd (and differentiable) then the sum (with the absolute value) usually diverges, but not necessarily as the above example and an earlier one ( f(x)= sin(2pi x)/2^{x} ) show. Most functions that are neither odd nor even will also have a divergent sum.

So honestly, how can you claim that "It will tell if the function is even or odd."?

### Re: Show us your articles! Or what's your Erdos number?

Posted: **Fri Sep 25, 2009 10:42 pm UTC**

by **njperrone**

You have read my replies right? You did realize I have admitted that things have been left out, right? So that means you do realize that I am working on it, right? Couldn't you have just said "Ok, show me the revision" instead of giving different counterexapmples. And yes, I admit that I overlooked functions of the form f(x)={g(x), condition; e(x), condition}. All of which I have said let me do some revision to include those if possible, or state them as functions that will not work.

### Re: Show us your articles! Or what's your Erdos number?

Posted: **Fri Sep 25, 2009 10:57 pm UTC**

by **njperrone**

jaap wrote:I have already given an example of a function that is neither even nor odd that has a zero sum:

f(x) = { 1-cos(2pi x) for 0<x<1; 0 elsewhere}

this actually does not sum up to either 0 or infinity. So is excluded, by definition, from the theorem.

jaap wrote:A worse example, here is an odd function with a zero sum.

f(x) = { 1-cos(2pi x) for x>=0; cos(2pi x)-1 for x<0 }

and this one actually works with my theorem.