We investigate the motion of (structured) particles and light in gravitational fields, as far as possible using analytical methods. More recently, we have directed our attention to fluid flows and plasmas in gravitational fields. For details see the personal websites of the team members.

The results of our research on equations of motion are applied to astrophysical problems like gravitational lensing, the shadows of black holes, the timing of pulsars, or accretion of fluid flows onto compact objects. For details see the personal websites of the team members.

We also analyse relativistic effects on satellites orbiting the Earth as well as Earth- or space-based clocks. The results are used to propose new tests of Special and General Relativity. For more details see the personal websites of the team members.

We are interested in fundamental questions in electrodynamics, such as the initial value problem in various types of media and the representation of dispersion relations in terms of Kummer surfaces. We are also working on nonlinear modifications of the vacuum Maxwell theory (Born-Infeld theory, Heisenberg-Euler theory, ... ) and on higher-order modifications of the vacuum Maxwell theory (Bopp-Podolsky theory). For more details see the personal websites of the team members.

Classical general relativity is in agreement with all observations to date, but it is widely believed that at a certain scale it has to be modified. We are particularly interested in Finsler geometry (i.e., in theories where the metric tensor depends not only on the spacetime point but also on the velocity), but also in other modifications of standard general relativity, e.g. f(R) theories, theories with torsion, and theories with nonminimal coupling. For more details see the personal websites of the team members.