2011/08/24 by David Rodriguez, Rodriguez, David
Physics and Astronomy · #FOS: Physical sciences #Quantum Physics (quant-ph) #quant-ph
paper · pdf · doi:10.48550/arxiv.1108.4823
2nd version: references and comment on recent work added
arxiv created 2011/08/30 · arxiv updated 2011/08/31
Assuming perfect detection efficiency, we present an (indeterministic) model for an EPR-Bohm experiment which reproduces the singlet correlations, without contradicting Bell's original locality condition. In this model we allow the probability distribution ρλ of the state λ at the source to depend parametrically on the orientation ξ of one of the measuring devices: ρλ(λ,ξ). In a Bell experiment, no-signaling between the source and each one of the devices would seem clearly sufficient to rule such an influence; however, not even schemes where the choice of observables takes place during the on-flight time of the particles can prevent, in some situations, a model of this type from violating the local bounds. In particular, a random shift ρλ(λ,ξ1) → ρλ(λ,ξ2) →...→ ρλ(λ,ξn) allows the model to perform a "subensemble selection" for each of the terms involved in the inequality (analogous to what goes on with the efficiency loophole), whenever some correlation of those ρλ-shifts with the sequence of measurement choices is allowed. That correlation does not necessarily imply signaling during the photon on-flight time.