My research concerns questions in geometric analysis and the investigation of nonlinear partial differential equations (pde) with the main focus on the Einstein equations in general relativity (GR). In GR, the geometry of the solution spacetimes has direct implications in physics and astrophysics. A major part of my research focuses on spacetimes exhibiting gravitational waves and their memory effect (a permanent change of the spacetime by gravitational radiation). Hereby, I link pure mathematics to physics and experiments. My research is driven by the motivation to unravel the complex interplay between mathematics and physics, manifesting in exceptionally strong ways in general relativity.