most recent 30 from http://mathoverflow.net 2013-05-24T08:25:05Z http://mathoverflow.net/feeds/user/9558 http://www.creativecommons.org/licenses/by-nc/2.5/rdf http://mathoverflow.net/questions/34215/how-do-professional-mathematicians-learn-new-things student 2010-08-02T06:48:01Z 2012-01-08T00:48:42Z

<p>How do professional mathematicians learn new things? How do they expand their comfort zone? By talking to colleagues? </p>

http://mathoverflow.net/questions/40256/is-there-a-todd-coxeter-algorithm-for-rings student 2010-09-28T03:08:59Z 2010-09-28T14:18:53Z

<p>The question above.</p>

http://mathoverflow.net/questions/38758/math-journals-reputation student 2010-09-15T01:42:20Z 2010-09-15T02:25:14Z

<p>Are these math journals considered to be prestigious by the math community: </p> <ul> <li>Studia Mathematica</li> <li>Israel Journal of Mathematics</li> <li>Positivity</li> <li>Mathematische Annalen</li> <li>Topology Proceedings</li> </ul>

http://mathoverflow.net/questions/37432/continuous-function student 2010-09-01T21:49:46Z 2010-09-01T21:49:46Z

<p>Suppose $f(x) = \begin{cases} 0 \ \ \text{if} \ x \ \text{is irrational} \newline \frac{1}{n} \ \ \text{if} \ x = m/n \ \text{in lowest form} \end{cases}$</p> <p>To show that $f$ is continuous at all irrational numbers in $(0,1)$ let $a$ be an irrational in the interval. Let $\epsilon$ be given. Choose $q$ such that $1/q &lt; \epsilon$. Why are thee are at most $1+2+ \cdots + (q-1)$ rationals in $(0,1)$ of the form $m/n$ where $n

http://mathoverflow.net/questions/34290/what-are-some-interesting-corollaries-of-the-classification-of-finite-simple-gro student 2010-08-02T18:10:50Z 2010-08-06T10:21:56Z

<p>The classification of finite simple groups -- whether it be viewed as finished, or as a work in progress -- is (or will be) without doubt an enormous achievement. It clearly sheds a great deal of light on the structure of finite groups. However, as with the classification of simple Lie algebras, one might expect this to have a significant impact outside of the immediate subject. So what are some of the known, or expected, applications to the classification outside of finite group theory?</p> <p>NB: This major edit is an attempt to extract what I'm guessing is the essence of the question. -D.A.</p> <p>Extra edit by Will Jagy. First, quoting a comment below: $$ $$ To anybody who is considering casting the 5th and final vote to close: Please wait at least a day or so before doing so! Whether or not this question should be closed, there's not a great reason to get too hasty here. Kevin Lin. </p> <p>Next, some rather negative comments you might be able to view below concern the initial version of the question, which one might be able to see by viewing the edit history.</p> <p>To anyone who has doubts about the proof, please see <a href="http://ams.org/notices/200407/fea-aschbacher.pdf" rel="nofollow">http://ams.org/notices/200407/fea-aschbacher.pdf</a> and do not debate that particular matter here. </p>

http://mathoverflow.net/questions/34606/mathematicians-and-writing student 2010-08-05T10:35:55Z 2010-08-05T12:00:14Z

<p>Do many mathematicians write a lot (including expository articles)? Or are there a fair majority of mathematicians that just write papers and don't bother with expository material? Which is better? Do mathematicians lose out if they do not write expository material?</p>

http://mathoverflow.net/questions/34146/what-is-the-motivation-of-the-definition-of-the-correlation-coefficient student 2010-08-01T20:04:04Z 2010-08-02T00:04:10Z

<p>Why do we define the correlation coefficient of two random variables $X$ and $Y$ as $\rho_{XY} = \frac{\text{Cov}(X,Y)}{\sigma_{x} \sigma_{y}}$? Doesn't $\text{Cov}(X,Y)$ tell us enough information about the dependence of $X$ on $Y$? </p>

http://mathoverflow.net/questions/34070/motivation-of-moment-generating-functions student 2010-08-01T00:02:07Z 2010-08-01T14:39:54Z

<p>What is the motivation of defining the mmoment generating function of a random variable $X$ as: $E[e^{tX}]$? I know that one can obtain the mean, second moment, etc.. after computing it. But what was the intuition in using $e^{x}$? Is it because its one-to-one and always increasing?</p>

http://mathoverflow.net/questions/40716/do-you-find-that-math-is-a-cumulative-process student 2010-10-01T06:36:28Z 2010-10-01T06:36:28Z

What do you mean?

http://mathoverflow.net/questions/40576/where-can-i-find-noam-elkies-phd-thesis student 2010-09-30T05:30:15Z 2010-09-30T05:30:15Z

It used to be online and now its not. It has to be somewhere online.

http://mathoverflow.net/questions/40576/where-can-i-find-noam-elkies-phd-thesis student 2010-09-30T05:27:00Z 2010-09-30T05:27:00Z

What do you mean? I dont live near him......

http://mathoverflow.net/questions/40521/operations-on-monoids student 2010-09-29T20:10:15Z 2010-09-29T20:10:15Z

7 mod 2 = 1 9 mod 5 = 4

http://mathoverflow.net/questions/40336/is-courants-differential-and-integral-calculus-a-good-book student 2010-09-28T16:59:04Z 2010-09-28T16:59:04Z

What was the typo?

http://mathoverflow.net/questions/40336/is-courants-differential-and-integral-calculus-a-good-book student 2010-09-28T16:29:56Z 2010-09-28T16:29:56Z

I dont want to.

http://mathoverflow.net/questions/40211/isnt-this-paul-erdos student 2010-09-27T20:51:17Z 2010-09-27T20:51:17Z

Okay....but can someone please at least confirm if I am correct?

http://mathoverflow.net/questions/40202/was-terry-tao-tutored-by-paul-erdos-at-one-point-of-his-life student 2010-09-27T20:47:52Z 2010-09-27T20:47:52Z

No its right here: <a href="http://www.youtube.com/watch?v=xKWm-zPHnrw#t=044" rel="nofollow">youtube.com/watch?v=xKWm-zPHnrw#t=044</a> Isn't that Paul Erdos?

http://mathoverflow.net/questions/40202/was-terry-tao-tutored-by-paul-erdos-at-one-point-of-his-life student 2010-09-27T19:56:57Z 2010-09-27T19:56:57Z

Why Will.......?

http://mathoverflow.net/questions/40197/what-are-some-good-reader-friendly-analysis-books-that-have-solutions student 2010-09-27T19:35:28Z 2010-09-27T19:35:28Z

But I think the people here can provide better recommendations.

http://mathoverflow.net/questions/40197/what-are-some-good-reader-friendly-analysis-books-that-have-solutions student 2010-09-27T19:28:40Z 2010-09-27T19:28:40Z

I am studying for the Math GRE. I need a review of it since I havent done it in about 2 years. And what do you mean by your last sentence?

http://mathoverflow.net/questions/38778/what-laptoptops-are-best-for-mathematics student 2010-09-15T05:07:07Z 2010-09-15T05:07:07Z

Because I am trying to find a good laptop to be more productive. I have a very big one.

http://mathoverflow.net/questions/38758/math-journals-reputation student 2010-09-15T01:55:06Z 2010-09-15T01:55:06Z

should just be positivity

http://mathoverflow.net/questions/34587/dimension-of-group student 2010-08-05T10:54:23Z 2010-08-05T10:54:23Z

Thanks. I went into limbo so time slowed down and I had time to learn all this.

http://mathoverflow.net/questions/34571/what-is-the-use-of-cosets student 2010-08-04T23:47:21Z 2010-08-04T23:47:21Z

Well try and see it then.