Résultats de recherche pour « Bell-CHSH Inequalities »

The Bell/CHSH inequalities of quantum physics are identical with the inequalities derived in mathematical psychology for the problem of selective influences in cases involving two binary experimental factors and two binary random variables recorded in response to them. The following points are made regarding cognitive science applications: (1) compliance of data with these inequalities is informative only if the data satisfy the requirement known as marginal selectivity; (2) both violations of marginal selectivity and violations of the Bell/CHSH inequalities are interpretable as indicating that at least one of the two responses is influenced by both experimental factors.

Unitary operators are employed to investigate the violation of the Bell-CHSH inequality. The ensuing modifications affecting both classical and quantum bounds are elucidated. The relevance of a particular class of unitary operators whose expectation values are real is pointed out. For these operators, the classical and quantum bounds remain unaltered, being given, respectively, by 2 and 2 2 . As examples, we discuss the explicit realization of phase space Bell-CHSH inequality violation and the Weyl unitary operators for a real scalar field in relativistic Quantum Field Theory.

A numerical setup for the Bell-CHSH inequality for causal diamonds in $1+1$ Minkowski spacetime is presented. Upon choosing a suitable set of test functions supported in the diamonds, sensible violations are reported for the correlation function of Weyl operators of a real scalar massive field in the vacuum state.

Abstract A numerical setup for the Bell-CHSH inequality for causal diamonds in $$1+1$$ 1 + 1 Minkowski spacetime is presented. Upon choosing a suitable set of test functions supported in the diamonds, sensible violations are reported for the correlation function of Weyl operators of a real scalar massive field in the vacuum state.

Abstract The Einstein–Podolsky–Rosen paradox and the Bell-type inequalities play significant role in understanding of quantum nonlocality and the foundations of quantum theory and quantum technologies. In this paper, we note that the usual derivation of the violation of Bell-type inequalities can be applied actually only for small distances between detectors. It does not take into account the dependence of the quantum mechanical wave function on space-time variables. We study the behavior of entangled photons obtained in spontaneous parametric down-conversion (SPDC) experiments and show that at large distances there is in fact no violation of the Bell-CHSH inequalities. We show that the initial entangled states become disentangled at large space-like distances. This does not contradict the violation of Bell inequalities observed at small distances between detectors. We propose an experiment to study the dependence of the quantum correlation function and Bell value on increasing distance between detectors. We predict that these quantities decrease inversely proportional to the increase of the distance between the detectors.