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location London, United Kingdom
age 26
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BSc in Physics at the National Autonomous University of Mexico (UNAM). Currently doing an MRes+PhD at the Centre for Doctoral Training in Controlled Quantum Dynamics at Imperial College London.


Jul
1
revised Fourier series is to Fourier transform what Laurent series is to …?
added 588 characters in body
May
8
awarded  Yearling
Apr
11
comment Approximating dirac delta function with sinc functions
This feels a bit circular. Isn't the integral in question the key element of the double-Fourier-transform theorem you invoke at the end?
Apr
10
comment Approximating dirac delta function with sinc functions
Oh, yes, you are right - that's pretty subtle. You are again correct, it is cancellations and not absolute convergence that makes $K$ vanish, so it is essentially a version of the Riemann-Lebesgue lemma. I will redo that section when I have time.
Apr
10
comment Approximating dirac delta function with sinc functions
Sorry, I didn't see that modification. You are right that the first term was incorrect. Your third term is not.
Apr
10
comment Approximating dirac delta function with sinc functions
Yes, that is correct. Apologies.
Apr
10
revised Approximating dirac delta function with sinc functions
deleted 10 characters in body
Apr
8
revised Approximating dirac delta function with sinc functions
Removed brackets from QED symbol.
Apr
8
answered Approximating dirac delta function with sinc functions
Apr
2
comment How can a piece of A4 paper be folded in exactly three equal parts?
And of course this has the advantage of utterly befuddling the recipient.
Mar
19
comment Non-invertible operators
You should really split this question up into two. The first question is not quite clear: are you asking "are there linear operators on some vector space whose matrix representation is singular?"? If so, you should make it that precise.
Mar
8
comment Do we need to formally teach the Greek Alphabet?
Note also that $\sum$ doesn't "start with" an S, it is an S. Similarly for $\prod$.
Mar
3
answered Help proving exercise on sequences in Bartle's Elements
Mar
3
comment Help proving exercise on sequences in Bartle's Elements
Re: your last question, for the sequence $x_n=2+1/n$ the ratio limit is exactly one. For the criterion to apply, you need it to be strictly smaller than that.
Feb
10
comment Define positions of a set of points given (only) the distances between them
@Andrewb If you provide a clear description of how you get from your initial distances to the new ones, then it will be easier to see. Be aware, though, that even with small perturbations if you do not have some specific geometric constraints in general the minimal dimension will still be $n-1$, because the determinant of the relevant matrix is a continuous function, and its zeros have measure zero. Nevertheless, the $(n-1)$-volume will be very small, though.
Feb
10
comment Define positions of a set of points given (only) the distances between them
Re: your edit, it's not exactly clear what you mean. If you mean you have a set of points $\{p_k\}$ and a smooth function $f$, and you want to move each point by a multiple of the gradient, i.e. $p_k\mapsto p_k+h\nabla f(p_k)$, then there you have your answer. It's not clear what you mean by "multiply each distance by the appropriate mean gradient", but it sounds awfully like equating a vector to a scalar. If you provide more specific details about what you mean then I'll address that.
Feb
10
answered Define positions of a set of points given (only) the distances between them
Feb
3
comment First variation of Area applied to minimal surfaces
It would help if you supplied more details on what formula you're confused about and what context it appears in.
Jan
28
revised Why is it trivial that $\left(1+\frac{2\ln3}{3}\right)^{-3/2}\leq\frac{2}{3}$?
Made title reflect the question.
Jan
28
suggested suggested edit on Why is it trivial that $\left(1+\frac{2\ln3}{3}\right)^{-3/2}\leq\frac{2}{3}$?