This book presents a collection of novel contributions and reviews by renowned researchers in the foundations of quantum physics, quantum optics, and neutron physics. It is published in honor of Michael Horne, whose exceptionally clear and groundbreaking work in the foundations of quantum mechanics and interferometry, both of photons and of neutrons, has provided penetrating insight into the implications of modern physics for our understanding of the physical world. He is perhaps best known for the Clauser-Horne-Shimony-Holt (CHSH) inequality. This collection (...) includes an oral history of Michael Horne's contributions to the foundations of physics and his connections to other eminent figures in the history of the subject, among them Clifford Shull and Abner Shimony. Among the editors and contributors are John Clauser and Anton Zeilinger, recipients of the Nobel Prize in Physics 2022. (shrink)

The Greenberger–Horne–Zeilinger argument against noncontextual local hidden variables is recast in quantum logical terms of fundamental propositions, states and probabilities. Unlike Kochen–Specker- and Hardy-like configurations, this operator based argument proceeds within four nonintertwining contexts. The nonclassical performance of the GHZ argument is due to the choice or filtering of observables with respect to a particular state. We study the varieties of GHZ games one could play in these four contexts, depending on the chosen state of the GHZ basis.

I describe a new framework for the articulation and analysis of Bell's theorems for arbitrarily complicated discrete physical scenarios. The framework allows for efficient proof of some new results, as well as generalizations of some older results already known for simpler cases. The generalized known results are: satisfaction of all Bell inequalities is equivalent to the existence of a joint probability function for all possible measurement contexts and stochastic versions of Bell's theorem are not stronger than deterministic versions. The new (...) results are: the straightforward generalization of parameter independence is inadequate when there are more than two observers, parameter independence is a necessary condition for observable probabilities to satisfy the Bell inequalities, and if the primary states can appear in isolation, and the observable probabilities satisfy all Bell inequalities, then parameter independence is a necessary condition for the primary states, too. (shrink)