Multi-time Structures from Many-body Dynamics

When many quantum degrees of freedom interact, surprising and intricate physics emerges. Traditionally, research in this area has focused on the properties of many particles at a single time. This thesis extends this paradigm, studying the properties of a single particle across many time steps. Key to our results is a mathematical description which captures how past interactions influence future outcomes of quantum measurements. We reveal properties of quantum chaos, describe conditions for the emergence of thermodynamics, and develop tools to simulate complex dynamics. This research opens doors to a deeper understanding of fundamental phenomena and advances in simulation methods.