Per Alexandersson

Zurich, Switzerland

www2.math.su.se/~per

Age: 27

Currently interested in Schur functions 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.

10h
answered Is real analytic function good enough (see problem)?
19h
comment Is polynomial chaos expansion interesting to surrogate surface?
I have trouble to understand what you are doing; perhaps some references would help.
22h
comment Algorithm for determining when polynomial iteration is bounded?
@SRJ: The reference I got is this: mathoverflow.net/a/100391/1056, which further points to math.grinnell.edu/~chamberl/papers/mario_digits.pdf The problem seems to be from 2000.
1d
comment Rationale behind an requirement on Turing machines
Ah, nice encoding scheme!
1d
comment Algorithm for determining when polynomial iteration is bounded?
@RobertIsrael: True, but in the filled version, you can essentially paint all points that converges nicely (which are outside the julia set), so this is no surprise. The points in the julia set are the "hard" ones.
1d
awarded Yearling
1d
awarded Autobiographer
1d
reviewed Approve suggested edit on Real-world applications of mathematics, by arxiv subject area?
1d
comment Can there ever be symbolic formalism without intuitive heuristics?
To answer "could anyone ever create a symbolic formalism without starting with an intuitive seed?", Yes, I have seen such a thing; there is a book (cant remember the title), with a collection of letters from amateur "mathematicians" sent to universities ("proofs" of RH, etc). One such letter contained something which did not have any intuition, it was just a ramble of something like "every FOOP is a GOOP, and every GOOP has a subGOOP or a LoopFoop".
1d
answered Game on the tree
1d
comment Algorithm for determining when polynomial iteration is bounded?
Ah, yes :). Fixed!
1d
revised Algorithm for determining when polynomial iteration is bounded?
missing words added
1d
revised Algorithm for determining when polynomial iteration is bounded?
added 163 characters in body
1d
answered Algorithm for determining when polynomial iteration is bounded?
2d
awarded Nice Answer
2d
revised Skew Kostka coefficients from Littlewood-Richardson Coefficients
deleted 2 characters in body
2d
accepted Normality property of powers of integers?
Aug
23
comment What is a definition of Recursion and Iteration?
Recursion is a very general concept, and applies to very many different fields. Sets, measures, sequences and functions can have recursive definitions. Thus, "recursion" is a loose word, similar to "fractal". There are several definitions, and no consensus, but most people (mathematicians) "knows" that both things are.
Aug
23
reviewed Approve suggested edit on Lifting analytic map
Aug
23
comment Game on the tree
In each step, there is a finite set of moves. For each move, you reach a smaller tree, and for this, (by recursion), you know already who will win in that game. Therefore, as a PROGRAMMING problem, it is quite straightforward. The hard part is to optimize it to run in decent speed (I guess it is about isomorphisms for binary trees that is the key thing).
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