Be welcome ye visitors! On this page you can find information on my mathematical research and the algorithms related to it.

You can peruse my Ph.D. thesis and articles, as well as some preprints, at Research, along with a description of my research interests. Algorithms, such as those developed for my thesis, can be found at Algorithms. Notes from talks that I have given are at Notes. Some links, of mathematical and non-mathematical nature, are at Links.

Should you have any questions, comments, or hate mail, then you can send it to sijsling 'at' gmail 'dot' com.

I am currently at the Universität Ulm, at the Institut für Reine MathematikTo the right is a photo of me in front of another institute where I do not work.

*Quickly climbs onto a soapbox before you can go*

I know, I know, you are here for the mathematics. But if you have a minute more to spare, then please use it to reflect on this report by Amnesty and take its message to heart: in a global world, we can and should speak up together against what ails it, as no government will do it for us without a clear democratic nudge. A few more things to take away are at Links, if this speaks to you.