hi!

All physical processes happen in time, and time is everywhere. But how is time at one place related to time at another place? What sounds like a trivial questions, is for highly accurate clocks actually very complicated. For example, heigths and rotations have to be considered!

The German Research Foundation (DFG) now funded the new research unit  "clock metrology" that will tackle these and related questions, that have major impact on the definition of reference frames and, therefore, on the quantization of changes on Earth e.g. due to climate change. I am proud to be part of this research team!

Black holes are often surrounded by matter in the form of a disc, that "feeds" the central black hole, a process known as accretion. In March 2023, we start a new research project funded by the German Research Foundation (DFG) to study the influence of electromagnetic interactions in analytical models of such accretion discs. This is, for example, of interest to understand the polarization in the first pictures of black holes, recently published by the Event Horizon Telescope collaboration. I am already excited to see the results!