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 Mathematik. To 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.