Bell argument: Locality or Realism? Time to make the choice
Tuesday, 14 May. 2013, 11:00 - 12:00
Presenter: Andrei Khrennikov, Linnaeus University, Växjö-Kalmar, Sweden
Host: C. Brukner
Where: IQOQI Seminar Room, 2nd Floor, Boltzmanngasse 3, 1090 Vienna
Abstract: The talk is about a possible resolution of the nonobjectivity-nonlocality dilemma in quantum mechanics in the light of experimental tests of the Bell inequality for two entangled photons and a Bell-like inequality for a single neutron. The conclusion is that these experiments show that quantum mechanics is nonobjective: that is, the values of physical observables cannot be assigned to a system before measurement. Bell's assumption of nonlocality has to be rejected as having no direct experimental confirmation, at least thus far. The relationships between nonobjectivity and contextuality are also considered. Specifically, the impact of the Kochen-Specker theorem on the problem of contextuality of quantum observables is analyzed. It is argued that, just as von Neumann's "no-go" theorem, the Kochen-Specker theorem is based on assumptions that do not correspond to the real physical situation. Finally, there will be presented a theory of measurement based on a classical, purely wave model (pre-quantum classical statistical field theory), a model that reproduces quantum probabilities. In this model continuous fields are transformed into discrete clicks of detectors. While this model is classical, it is nonobjective. In this case, nonobjectivity is the result of the dependence of experimental outcomes on the context of measurement, in accordance with Bohr's view.
 A. Khrennikov, Contextual Approach to Quantum Formalism, Springer, 2010.
 arxiv.org/abs/1108.0001; published in "Int. J. Theor. Physics", 2012.