I'm a Professor at the Mathematical Institute of the Georg-August University of Göttingen. I am also the conservator of the models collection. Here is a map of Göttingen with important mathematical places.
- Search in the new catalogue of the mathematical library:
Publications (HTML), Google Scholar and arXiv
I am currently interested in understanding fractal behaviour in
group theory and algebra, and its use for holomorphic dynamical
- Curriculum vitae:
- In HTML or PDF format
Self-similar, or fractal, objects abound in mathematics; depending
on context, they mean a space containing several almost disjoint
copies of itself as subspaces; a group containing the direct product
of copies of itself as a subgroup; or an algebra containing a matrix
algebra over itself as a subalgebra. The fractalness is
algebraically encoded via the collection of inclusion maps of these
subobjects in their common parent.
A self-similar group may be associated with any complex dynamical
system, and yields an extremely potent algebraic invariant of that
dynamical system up to isotopy and conjugation. I currently explore
more deeply the connection between complex dynamics and fractal
groups, and use it to extend the classification of degree-two
polynomials (described by points in the Mandelbrot set) to
arbitrary-degree rational functions.
- Nerd score:
- The FR GAP-package, for manipulation of groups and semigroups generated by automata.
- The Float GAP-package, for manipulation of real, complex, interval etc. floating-point numbers.
- Göttingen collection of mathematical models
I received from
speakers in the conference "Trends and Directions in Conformal
Dynamics" in Oberwolfach, October 17-21, 2008
crashes in everyday life -- a
commented photo gallery
Movies illustrating the "twisted rabbit" paper in
progress with V. Nekrashevych.
- How I Rank in Hell
- My Images
- A movie I
made (hi-rez) of the Schreier graph of the Gupta-Sidki group,
and MPEG-1 format.
- Bibliography (BibTeX) of papers I'm interested in,
and tar.gz format.
- LaTeX2e style file for sending notes
in LaTeX to the CRAS (Comptes Rendus de l'Académie des
Sciences de Paris), in zip
and tar.gz format (contains G. Perec's article
"Experimental... Cantatrix sopranica L." as a sample).