Abstract

The Bell-Kochen-Specker theorem proves the impossibility of a classical hidden variable theory that would explain the quantum mechanical predictions on a single system, at least if the classical theory is “non-contextual”. In the talk I will review the basic argument, and discuss recent ideas to test quantum contextuality in experiments, via so-called non-contextual inequalities. These inequalities, starting with the work of Klyachko et al., exhibit a rich combinatorial structure relating to topics in graph theory. I will also discuss which hidden variable theories are ruled out by actual experiments, in the light of the recent “finite precision” debate initiated by Meyer, Kent and Clifton.

[Based on joint work with Adan Cabello and Simone Severini, arXiv:1010.2163]

There will be a wine reception after the talk with the guest speaker.

Free for members, £2 for non-members