4,216 reputation
21747
bio website bruno.stonek.com
location Montevideo, Uruguay
age 25
visits member for 3 years, 11 months
seen 1 hour ago

Math student at Université Paris 13.


Aug
6
awarded  Good Question
Aug
4
comment What's the “geometry” in “geometric multiplicity”?
Well, an eigenspace is a vector subspace, so if the geometric multiplicity is 1 then it is a line through the origin, if it is 2 then it is a plane through the origin, etc. This is just a wild guess, but it seems plausible that the name might come from this interpretation.
Aug
3
comment Euler's Constant: The asymptotic behavior of $\left(\sum\limits_{j=1}^{N} \frac{1}{j}\right) - \log(N)$
@DJC: I think it is a bit shocking to use displaystyle in the title.
Aug
3
revised Normal closure of a radical extension is radical
edited for clarification on what is asked
Aug
3
comment Normal closure of a radical extension is radical
I must say I'm a bit surprised by the lack of answers to this question. It shouldn't take too long to answer for somebody comfortable with Galois theory.
Aug
1
revised Normal closure of a radical extension is radical
edited tags
Jul
31
comment Normal closure of a radical extension is radical
@Dylan: What puzzles me is that if all the details I wrote out are necessary, then I think the author should have been a bit more verbose on the proof...
Jul
31
asked Normal closure of a radical extension is radical
Jul
28
comment Bernoulli's representation of Euler's number, i.e $e=\lim \limits_{x\to \infty} \left(1+\frac{1}{x}\right)^x $
Related: planetmath.org/?op=getobj&from=objects&id=10170
Jul
27
comment What does “formal” mean?
It should be noted that the first sense includes a really vast spectrum of degrees of formality. The way I see it, it includes usual textbook proofs (e.g. Folland's proof of Radon-Nikodým theorem is 'formal'), and 'logically' formal proofs, as in en.wikipedia.org/wiki/Formal_proof , which also serves as input for automated proof checking.
Jul
26
comment For what functions does $\int_{-\infty}^{\infty}x \sin(f(x))\,dx$ converge?
If the function is differentiable, "grows fast enough" seems to imply some condition on $\lim_{x\to \infty} f'(x)$.
Jul
26
awarded  Nice Question
Jul
20
comment Reference request: is mathematics discovered or created?
FWIW, I ended up writing the essay on something else (also math-related, though); so for those who were reluctant to throw out some ideas, be at ease: the answers and comments "only" contributed to my knowledge of these profoundly interesting matters.
Jul
19
comment Interpretation of a formula and truth
@Kaveh: thank you for your comments, I think I understand this better now.
Jul
18
comment Interpretation of a formula and truth
I understand. Still, I'm not fully convinced of why this is meaningful.
Jul
18
comment A simple question about sine and cosine
$sin(z)= \frac{e^{iz}-e^{-iz}}{2i}$ for complex $z$ is the first that comes to mind. There are others, see en.wikipedia.org/wiki/Sine for a continued fraction expression for example. Also, I remember Apostol defining sine and cosine in his Calculus by some fundamental properties...
Jul
18
revised Interpretation of a formula and truth
edited tags
Jul
17
comment Interpretation of a formula and truth
@André: But if in the end I just have to think as $\mathbb{N}$ as something "intuitive" and $0\cdot n=0$ as an intuitive truth, why then care for any formalism at all?
Jul
17
comment Interpretation of a formula and truth
@Zev: great, thanks! This is a bug that should be reported, actually.
Jul
17
accepted Models of hyperbolic geometry