From the string theory perspective it is as natural for space-time to be non-commutative as it is to be curved. Non-commutativity implies that different coordinates of an event cannot be measured exactly at the same time. This fuzziness of space-time can be parametrized by a two-form potential. However, different values sometimes result in the same non-commutative space. My collaborators and I have studied aspects of this "Morita equivalence" resulting in JHEP 0205:025,2002 and hep-th/0111077
An important non-perturbative ingredient in string theory are D-branes. Their geometry can often be related to field configurations in gauge theories on their world volume. Supersymmetry can be a powerful tool to understand this relation. For some contribution in this direction see Phys.Lett.B510:311-319,2001.
In 2000, I finished my PhD (Dr. rer. nat.) at the Albert-Einstein-Institut, Max-Planck-Institut für Gravitationsphysik in Hermann Nicolai's group on scattering in the M(atrix)-Model. Here is my thesis that contains results on spin-spin coupling in M-Theory, discusses the impossibility of having non-trivial scattering in the classical M(atrix)-Model and contains the (to my knowledge) first and so far only explicit calculation that shows that M(atrix)-Theory does not capture loop-effects in supergravity. See also JHEP 9805:012,1998, Nucl.Phys.B559:184-204,1999, and hep-th/0009134.
With H. Nicolai I have written lecture notes from his Trieste lectures on Supermembranes and M(atrix)-Theory. In contrast to the electronic version, the version in the printed proceedings has some misprints. Here is an erratum.
Together with Jens Hoppe I have written a review of recent developments in string theory intended for a wider physics audience: M für Membran? (in German).
My diploma thesis that was supervised by Hermann Nicolai and Anton van de Ven was concerned with heat-kernels in a constant supergravity back-ground. I was able to express the heat-kernel for an unconstrained super-field in terms of the heat-kernel of a scalar field in a constant gravitational back-ground that was recently described by I. Avramidi.
In the summer of 1995, I spent three months at the NEC Research Institute where I was introduced to the exiting world of protein folding . This resulted in my first (and so far most cited) publication: "Emergence of Preferred Structures in a Simple Model of Protein Folding" (Science 273 (1996) pp. 666-669)
I like to go scuba diving.
News: I now have a blog. Let's see if I can keep this alive without actually wasting too much time.
In spring 1997, I attended the NATO Advanced Study Institute at Cargese, Corsica on "Strings, Branes and Dualities". Here are some pictures I took.
Here you find some pictures I took at Strings '98
If you are going to give a talk at a conference, check this out! In case you sit in the audience, you might enjoy a game of stringy Bingo!.
In June 1999, I gave a series of public lectures "Phaser, Wurmloch Warpantriebe --- Star Trek und die moderne Physik". Have a look at the transparencies.