Per Alexandersson

Zurich, Switzerland

www2.math.su.se/~per

Age: 28

Currently interested in Schur functions, key Polynomials and semistandard Young tableaux and misc. related representation theory and combinatorics.

Phd thesis defended 2013, titled Combinatorial Methods in Complex Analysis.

I keep an eye out for interesting results related to complex dynamics, computability, and computer-assisted research. I use Mathematica extensively in my research. My other main programming languages are Java, LaTeX, PHP, C, etc.

Oh, and I like generative art.

8h
comment All relations among degree n monomials in n variables
What do you mean by relations? Taking both sides to the power $k$ in your example gives a new relation?
14h
awarded Nice Question
1d
comment Picking isometric map with slopes
One idea is to make a second render, with a unique color for each tile, and just match color with the one the user clicked on. This is a common technique..
1d
comment Koch snowflake construction in many dimensions
How about look at wikipedia? en.wikipedia.org/wiki/List_of_fractals_by_Hausdorff_dimension The Menger sponge should be a good candidate.
1d
revised What conditions imply that a function over $\mathbb{Z}$ is a polynomial?
added stuff
2d
answered What conditions imply that a function over $\mathbb{Z}$ is a polynomial?
Jun
29
comment When is a sequence the sum of two Beatty sequences?
Does this generalize if it is a sum more then two Beatty sequences?
Jun
29
comment What is this symbol?
To me, it looks a bit similar to \Re
Jun
29
comment When is a sequence the sum of two Beatty sequences?
As Max Alekseyev says, a sequence is an infinite object, and there are many irrational numbers to test... This question might very well be undecidable, and if not, the question if a sequence is a sum of a finite number of Beatty sequences might be...
Jun
29
revised Open problems/questions in representation theory and around?
added question about Kostka coeffs.
Jun
27
comment inequality in a shape of inclusion exclusion formula
If you reformulate it in terms of polynomial inequalities, this can be solved by computer algebra if I am not mistaken.
Jun
27
comment inequality in a shape of inclusion exclusion formula
Is this research or math competition?
Jun
25
comment Bayes' Rule where the probabilities are taken as conditional
this is more suitable over at math.stackexchange
Jun
25
comment Bayes' Rule where the probabilities are taken as conditional
this is more suitable over at math.stackexchange
Jun
24
comment How do I evaluate this sum :$\sum_{n=0}^{\infty} \frac{\sin(n!)}{\cos(n!)}$ if it's not open problem?
That was not intended; browsing on the phone apparently has some unexpected consequences.
Jun
23
comment Generate all non-isomorphic partitions $\pi = \{ \{1, ..., n-1\}, \{n\} \}$ for all graphs of order $n$
So, you want to count the number of isomorphism classes of connected graphs on $n$ vertices, with one distinguished vertex?
Jun
23
comment Asymptotics of coefficients of implicitely defined generating function
See also Chapter 5 in Generatingfunctionology by Wilf, math.upenn.edu/~wilf/gfologyLinked2.pdf
Jun
23
comment How do I evaluate this sum :$\sum_{n=0}^{\infty} \frac{\sin(n!)}{\cos(n!)}$ if it's not open problem?
@JoeSilverman: Ah, yes, it looks like $\log|f(n)|/\log(n) \leq 1.64$ for $n \leq 600$, and $g(N)=\sup_{n\leq N} \frac{\log|f(n)|}{\log(n)}$ is very close to being constant.
Jun
23
comment How do I evaluate this sum :$\sum_{n=0}^{\infty} \frac{\sin(n!)}{\cos(n!)}$ if it's not open problem?
Joe Silverman gives a good argument. I guess to actually prove that $n!$ mod $2\pi \mathbb{Z}$ is dense is quite nontrivial, and perhaps even an open problem.
Jun
23
answered How do I evaluate this sum :$\sum_{n=0}^{\infty} \frac{\sin(n!)}{\cos(n!)}$ if it's not open problem?
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