The Information-Theoretic Turn in Quantum Foundations

This project addresses an actively researched problem area in quantum information: the significance of information-theoretic constraints such as 'information causality' in the demarcation of quantum mechanics from other 'foil' theories. Progress in understanding the difference between classical, quantum, and superquantum correlations from this perspective is most likely to provide insights of fundamental significance with respect to the two Big Questions, about the measurement problem and what quantum information says about the nature of reality. The working hypothesis is that the presence of information-theoretic concepts at the fundamental level in theoretical physics reflects something profound about the nature of physical reality. Concrete outputs include a book and two peer-reviewed publications on just how and why physics in a quantum world requires reference to information, i.e., to agency and intervention. Specifically: What does it say about the nature of reality if physical theory at the most fundamental level is constrained by information-theoretic principles such as information causality? What does it say about the measurement problem? The aim is to consider novel approaches to concrete foundational problems in this area, and then, by taking a step back and reflecting on the meaning of what has been found, to make progress in answering the Big Questions. The project is expected to have an enduring impact, not only with respect to specific issues in quantum information, but also in a deeper understanding of the significance of the transition from a mechanical model of the universe to a computational or information-theoretic model.