Per Alexandersson

About me

Teaching

Fall 2020, I am teaching at Stockholm University. I teach Algebra and combinatorics, and also Matematik I - Seminarie. Moreover, I am available for supervising student projects.

Research

My field of research is representation theory and combinatorics, more specifically, polynomials given by structure constants (Kostka coefficients, characters of the symmetric group) and Jack generalizations of these, as well as chromatic symmetric functions, LLT polynomials and so on. I have also found an interest in the cyclic sieving phenomenon.

I am also a bit interested in special polynomials, for example real-rooted polynomials and polynomials obtained from combinatorial statistics. Finally, I must admit that I have a soft spot for tilings, discrete dynamical systems, NP-completeness and cellular automata.

History

Fall 2019–Summer 2020, I worked as a researcher at Stockholm University.

During 2017–2019, I was working as a postdoc with Svante Linusson at KTH (Stockholm). Before that, (2015–2017) I worked as a postdoc at University of Pennsylvania, with Jim Haglund, funded by a grant from the Knut and Alice Wallenberg foundation. In 2014, I worked as a postdoc at Universität Zurich, Schweiz with Valentin Féray.

In Spring 2013 I defended my thesis titled Combinatorial Methods in Complex Analysis, where Boris Shapiro was my primary advisor. My research interests are mainly combinatorics, complex analysis and algebraic geometry. My favorite research tools are Mathematica, OEIS, FindStat, MathOverflow and WolframAlpha.

Projects

Symmetric functions catalog

Want a quick overview of symmetric functions and their generalizations? See this catalog with a lot of background for people working with algebraic combinatorics.

Symmetric functions package

I use Mathematica for doing computations with symmetric functions. My Mathematica packages are avaiable on GitHub.

Other projects

My OEIS contributions: A115047, A194460, A227404, A276975, A277031, A294241, A335340.

In my spare time, I tinker a bit with a flame fractal renderer written in Java. You can browse the source on Sourceforge.