My work focuses on theories of gravity, spacetime structure, and how they interact with matter. Much of my work has been on Einstein's interpretation of general relativity and of other spacetime theories, and on the question of how Einstein's positions square with the modern debates in the foundations of general relativity. I am is particularly interested in the analysis and interpretation of black hole physics and gravitational wave physics. I have been an Editor of Albert Einstein's Collected Papers since 2010, and a PI of the DFG research unit “The Epistemology of the LHC” since 2017. As of 2023, I am the sole PI of the ERC consolidator grant “The Centre of Gravity”, which aims to provide a conceptual and historical analysis of the Renaissance of General Relativity between 1955 and 1975, in which most of the concepts and methods that now dominate black hole physics and gravitational wave physics originate.