Showing papers on "Kochen–Specker theorem published in 1983"

Nonlocality and the Kochen-Specker paradox

Abstract: A new proof of the impossibility of reconciling realism and locality in quantum mechanics is given. Unlike proofs based on Bell's inequality, the present work makes minimal and transparent use of probability theory and proceeds by demonstrating a Kochen-Specker type of paradox based on the value assignments to the spin components of two spatially separated spin-1 systems in the singlet state of their total spin. An essential part of the argument is to distinguish carefully two commonly confused types of contextuality; we call them ontological and environmental contextuality. These in turn are associated with two quite distinct senses of nonlocality. We indicate the relevance of our treatment to other related discussions in recent literature on the philosophy of quantum mechanics.

Bell's Theorem and Backwards-in-Time Causality

Abstract: Bell has shown that quantum mechanics is incompatible with the notion of locality. The present paper begins by considering the possibility of invoking backwards-in-time causality to explain this violation of locality. This then leads to an examination of the possible relevance of backwards-in-time causality to measurement outcomes in general. It is found that the situations in which it could be involved are limited owing to causality paradoxes.

On a local hidden-variable model with unusual properties

Abstract: We show that alocal hidden-variable model exists which violates Bell’s inequality. The correlation function depends on the definition of the time of coincidence, are obtained for arbitrarily small times of coincidence.

Bell's Theorem: Does the Clauser-Horne Inequality Hold for All Local Theories?

Abstract: On critique l'hypothese selon laquelle l'inegalite de Clauser Horne S(φ)≤1 est valable pour toutes les theories locales

Stochastic locality and conservation laws

Abstract: Proofs are available in the literature that Bell inequalities hold both for localdeterministic hidden-variable theories and for «local»stochastic hidden-variable theories. It is here demonstrated that stochastic hidden-variable theories which obey Bell inequalities do not admit the usual conservation laws involving more than one particle. Therefore, physically interesting stochastic theories (in which overall conservation principles hold)must violate Bell inequalities. The alleged «nonlocal» character of quantum mechanics is due entirely to the validity of such conservation principles involving spatially separated measurement outcomes. It is argued that the term «nonlocality» is not appropriate in this context.