Indefinite global time

Abstract

By studying the set of correlations that are theoretically possible between physical systems without allowing for signalling of information backwards in time, we here identify correlations that can only be achieved if the time ordering between the systems is fundamentally indefinite. These correlations, if they exist in nature, must result from non-classical, non-deterministic time, and so may have relevance for quantum (or post-quantum) gravity, where a definite global time might not exist.

References in corpus (5)

• A convergent hierarchy of semidefinite programs characterizing the set of quantum correlations
• Bounding the set of quantum correlations
• Non-locality distillation and post-quantum theories with trivial communication complexity
• Emergence of Quantum Correlations from Non-Locality Swapping
• Macroscopically local correlations can violate information causality