bio | website | eqnets.com |
---|---|---|
location | Inside the Beltway | |
age | ||
visits | member for | 4 years, 10 months |
seen | 23 hours ago | |
stats | profile views | 9,480 |
My mathematically-oriented work generally explores discrete geometric and probabilistic themes in physics, computation, and communication. Jack of most trades, master of none.
I can be reached at sh#eqnets#com (make the obvious substitutions for #).
Sep 6 |
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Topological description of inverting a knot
Here is a very coarse physical characterization: knots can arise via entropic forces, and are hard to untangle by the second law. |
Sep 5 |
awarded | Popular Question |
Sep 3 |
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The sum of the carries when adding and multiplying two numbers in base p
math.wayne.edu/~isaksen/Expository/carrying.pdf |
Sep 2 |
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Recognize this strange expression from linear algebra?
If I've handled my indices correctly then $2a_j = \sum_{k \ell} c_{k \ell} (c_{\ell j} - \delta_{\ell k}) g_{kj}$. |
Aug 26 |
awarded | Nice Answer |
Aug 22 |
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Is the sequence of Apéry numbers a Stieltjes moment sequence?
oeis.org/A228143 |
Aug 18 |
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Cohomology of the toric variety $X_\Sigma=\mathbb C^2\sqcup \mathbb C^2\big/\left((x,y)_1\sim(x^{-1},y^{-1})_2\right)_{x,y\neq 0}$
You might want to take a look at Ewald's book: books.google.com/books?id=EEiwI7k7Mx8C |
Aug 9 |
answered | Examples of unexpected mathematical images |
Jul 31 |
awarded | Popular Question |
Jul 31 |
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Reference request for instantons
You might also look at Chapter 8 of Ward and Wells' book on twistors. |
Jul 29 |
answered | Escape the zombie apocalypse |
Jul 29 |
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Reference request for instantons
It sounds like you're probably past this, but you might take a peek at section 13.2 of amazon.com/Classical-Theory-Fields-Valery-Rubakov/dp/0691059276 |
Jul 18 |
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Rediscovery of lost mathematics
Grassmann is another good example from your link... |
Jul 18 |
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Rediscovery of lost mathematics
en.wikipedia.org/wiki/Stark%E2%80%93Heegner_theorem#History |
Jul 18 |
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Notable mathematics during World War II
@Gerry: Ha! But I'd been to APG once upon a time and had a rather different impression--the ordnance was quite loud... |
Jul 2 |
awarded | Inquisitive |
Jul 2 |
awarded | Curious |
Jun 20 |
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Maximum of two normal random variables
en.wikipedia.org/wiki/… |
Jun 17 |
reviewed | Approve suggested edit on How do I make the conceptual transition from multivariable calculus to differential forms? |
Jun 12 |
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Method to Generate Random Mutually Orthogonal Unitary Matrices
As an aside to Carlo's comment, two mutually orthogonal unitaries can be easily constructed: take diagonal unitaries $U^{(j)} \in U(n)$ for $j = 1,2$ with $U^{(j)}_{kk} = \exp(i\theta^{(j)}_k)$. Orthogonality then means that $\sum_{k=1}^n \exp(i[\theta^{(2)}_k-\theta^{(1)}_k]) = 0$. This can be enforced by choosing $\theta^{(2)}_k-\theta^{(1)}_k = 2\pi k/n$. |