Space Isotropy and Homogeneity Principles Determine the Maximum Nonlocality of Nature
One of the fundamental questions in physics concerns the relation between spacetime and quantum entanglement. The spacetime is usually considered as a fixed background physical space, and the quantum entanglement is usually manifested as a ``spooky action at a distance" or the existence of ``nonlocality" in nature. Here, we propose the flat-space isotropy and homogeneity principles as the fundamental criteria for determining the maximum degree of nonlocality of nature. More specifically, we consider abstract and deterministic nonlocal-box models which have stronger correlations than in quantum mechanics, whereas therein instantaneous communication remains impossible. We impose space-symmetry group structures on these models and derive a measure for the degree of space symmetries. Surprisingly, there is a tradeoff or inconsistency between the degree of space symmetries and the degree of nonlocality, where this inconsistency is exactly lifted at the Tsirelson bound, as predicted by quantum physics and also predicted in the experiments. Moreover, we prove this result in the general framework of deterministic nonlocal models and conclude that the probabilistic interpretation of the nonlocal box models is an emergent property of the flat-space symmetries.