I am a mathematician. Currently I am Professor of Mathematics at the University of Bremen, Germany, as well as Adjunct Professor at the Okinawa Institute of Science and Technology, Japan, where I am the head of the Applied Topology Unit. Here are the official links: Bremen, OIST.

On this website I am maintaining some of the mathematical texts I have written over time. I wanted to make sure these are available for free download for everyone.

I also have a number of other interests which are reflected by the different topics you can click to from the main page.