13,637 reputation
11646
bio website mypage.iu.edu/~necolema
location Indiana
age 26
visits member for 3 years, 4 months
seen 13 hours ago

"Arithmetic is the hardest of the sciences, this is well-known." -V. Touraev

Comathematician: A device for turning cotheorems into ffee.


1d
comment Finding $10\otimes 8\otimes 8\otimes 8$ in $SU(3)$
@Omnomnomnom Thanks!
1d
comment Finding $10\otimes 8\otimes 8\otimes 8$ in $SU(3)$
Could you give a little context, or at least definitions? To the best of my knowledge, 10 and 8 are integers, not three-by-three unitary matrices.
2d
comment How is the exponential in the Fourier transform pulled out of the integrand?
Are they totally consistent with standard $\int (\mbox{integrand})\ dx$ through the rest of the book? I have seen physicists write $\int dx\ (\mbox{integrand})$ before. If that's the case, then they just changed the order of integration.
2d
comment Can a non-periodic function have a Fourier series?
@sgsdfg If two functions have different periods, they are in two entirely different function spaces.
2d
comment How does one see connectedness of a covering space?
... you are assuming the base is connected, yes?
2d
answered Can a non-periodic function have a Fourier series?
2d
comment Can a non-periodic function have a Fourier series?
@PeterHorvath Yes. I do not disagree with you.
2d
comment Can a non-periodic function have a Fourier series?
That's what the Fourier transform is. Except since you don't have integral frequencies, the sum is an integral.
Jan
13
answered Why do I get two times the base if it's squared when I multiply the value by four?
Jan
9
comment Question about integral of the product of two continuous functions.
@MPW You should make that an answer.
Dec
23
comment A calculation that goes awfully wrong if we let $\pi=22/7$
"That integral is clearly not zero" ... because the integrand is positive on $(0,1)$.
Dec
19
comment Proving limits using epsilon definition
It's often useful to look at the ratio of the dominant terms in the numerator and denominator. In this case, that ratio looks like 1/x, so you are led to consider proving it for 1/x and then adapting that to the original problem.
Dec
18
comment The cone of a topological space is contractible and simply connected
Many upvotes and no correcting answer do not necessarily mean that you are clear and correct. Even if you were completely wrong, I would still have heartily upvoted for investing effort into the problem and showing your work.
Dec
17
awarded  Good Answer
Dec
15
comment Any finite set is compact; what exactly is a finite set?
+1 for a question which demonstrates a thought process and outlines previous attempts at an answer.
Dec
15
comment What level of math is needed to learn fractional calculus?
Ok, I see more clearly what you mean.
Dec
15
comment What level of math is needed to learn fractional calculus?
You suggest jumping into Hormander, Vol 1, after just two semesters of baby Rudin? Or is there an easier reference for microlocal analysis you have in mind?
Dec
5
answered Is there a non-simply-connected space with trivial first homology group?
Dec
3
comment Riemann-Lebesgue Lemma for Spherical Harmonics expansion
This is because on a closed Riemannian manifold, eigenfunctions of the Laplace operaror form an orthonormal basis of $L^2$.
Dec
3
comment Riemann-Lebesgue Lemma for Spherical Harmonics expansion
The spherical harmonic expansion is the fourier expansion on the round sphere. Spherical harmonics : sphere :: sines and cosine : circle.