Nonlocal hidden-variable theories and quantum mechanics: An incompatibility theorem

Research output: Contribution to journalReview article

Abstract

It is argued that among possible nonlocal hidden-variable theories a particular class (called here "crypto-nonlocal" or CN) is relatively plausible on physical grounds. CN theories have the property that (for example) the two photons emitted in an atomic cascade process are indistinguishable in their individual statistical properties from photons emitted singly, and that in the latter case the effects of nonlocality are unobservable. It is demonstrated that all CN theories are constrained by inequalities which are violated by the quantum-mechanical predictions; these inequalities bear no simple relation to Bell's inequalities, and an explicit example is constructed of a CN theory which violates the latter. It is also shown that while existing experiments cannot rule out general CN theories, they do rule out (subject to a few caveats such as the usual ones concerning the well-known "loopholes") the subclass in which the photon polarizations are linear.

Original languageEnglish (US)
Pages (from-to)1469-1493
Number of pages25
JournalFoundations of Physics
Volume33
Issue number10
DOIs
StatePublished - Oct 1 2003

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incompatibility
quantum mechanics
theorems
photons
linear polarization
bears
bells
cascades
predictions

Keywords

  • Hidden-variable theories
  • Nonlocality
  • Quantum mechanics

ASJC Scopus subject areas

  • Physics and Astronomy(all)

Cite this

Nonlocal hidden-variable theories and quantum mechanics : An incompatibility theorem. / Leggett, A. J.

In: Foundations of Physics, Vol. 33, No. 10, 01.10.2003, p. 1469-1493.

Research output: Contribution to journalReview article

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