Quantum Interference and the Limits of Separability

Abstract Quantum theory implies, and empirical evidence confirms, that while particles can exhibit wave-like behavior in interferometric experiments, this behavior is so limited as not to allow for third- and higher-order interference. The article at hand shows that this possibility-impossibility structure suggests the universal validity of a principle that regulates statistical correlations between spatiotemporally localized events, independently of the nature of the objects that may or may not partake in these events. Roughly, and up to some qualifications, the said principle mandates that any joint influence of m mutually spacelike separated events on another event, be such, that it can be separated by at least $$\lceil \frac{m}{2} \rceil$$ mediating events, and in some cases, by no more than $$\lceil \frac{m}{2} \rceil$$ mediating events. The structure of quantum interference thus teaches us that events can influence each other in a non-separable fashion, but that this non-separability has a certain exactly quantifiable limit.