TU Darmstadt 2023 Davide Proment, School of Mathematics, University of East Anglia, U.K. 1.5 months in 2023 and 2024 at U Heidelberg Rainer Fries, Texas A&M University, USA 4.5 months in 2023 at U Frankfurt [...] 2022 and 2023 at U Münster, U Heidelberg and GSI Volker Koch, Lawrence Berkeley Laboratory, USA 6 months in 2023 at GSI Darmstadt Takaharu Otsuka, University of Tokyo, Japan 2 weeks in June 2023 at GSI and [...] Current & Upcoming Davide Proment, School of Mathematics, University of East Anglia, U.K. 1.5 months in 2023 and 2024 at U Heidelberg Joannis Papavassiliou, Department of Theoretical Physics, U Valencia, Spain