Nonlocality and the Quantum Born Rules

Damian Canals‐Frau

Yeong Deok Han, Taeseung Choi

Quantum theory has nonlocal correlations, which bothered Einstein, but found to satisfy relativistic causality. Correlation for a shared quantum state manifests itself, in the standard quantum framework, by joint probability distributions that can be obtained by applying state reduction and probability assignment that is called Born rule. Quantum correlations, which show nonlocality when the shared state has an entanglement, can be changed if we apply different probability assignment rule. As a result, the amount of nonlocality in quantum correlation will be changed. The issue is whether the change of the rule of quantum probability assignment breaks relativistic causality. We have shown that Born rule on quantum measurement is derived by requiring relativistic causality condition. This shows how the relativistic causality limits the upper bound of quantum nonlocality through quantum probability assignment.

Amit Goswami

Dipankar Home

Henry Pierce Stapp

F. J. Duarte

The essence of quantum mechanics involves indistinguishability , superposition , Heisenberg's uncertainty principle , nonlocality of the photon , and Born's rule . As a whole, these concepts integrate the indeterminacy of quantum mechanics. Indistinguishability and superposition are quantum concepts that together with probability amplitudes are crucial coherent concepts that are part of the first layer of quantum mechanics. Albeit functioning at the mathematical unmeasurable realm of quantum physics, these concepts, nevertheless, faithfully reflect the reality of experimental configurations. Heisenberg's uncertainty principle, nonlocality of the photon, and Born's rule manifest themselves in the second layer of quantum mechanics: the measurable realm . Here, all these five concepts are considered from the experimentalist's perspective. This chapter concludes with the observation that the essence of quantum mechanics is closely and intrinsically entangled with the ethos of physics: the experiment .