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Schrödinger’s Paradox and Proofs of Nonlocality Using Only Perfect Correlations

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Abstract

We discuss proofs of nonlocality based on a generalization by Erwin Schrödinger of the argument of Einstein, Podolsky and Rosen. These proofs do not appeal in any way to Bell’s inequalities. Indeed, one striking feature of the proofs is that they can be used to establish nonlocality solely on the basis of suitably robust perfect correlations. First we explain that Schrödinger’s argument shows that locality and the perfect correlations between measurements of observables on spatially separated systems imply the existence of a non-contextual value-map for quantum observables; non-contextual means that the observable has a particular value before its measurement, for any given quantum system, and that any experiment “measuring this observable” will reveal that value. Then, we establish the impossibility of a non-contextual value-map for quantum observables without invoking any further quantum predictions. Combining this with Schrödinger’s argument implies nonlocality. Finally, we illustrate how Bohmian mechanics is compatible with the impossibility of a non-contextual value-map.

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Notes

  1. For the reader who might worry that, according to special relativity, the temporal order, “before” and “after,” depends on the reference frame for spatially separated events, let us say that everything here refers to the reference frame where the laboratory in which the measurements are performed is at rest. See [37] for a discussion of the tensions that exist, due to such experiments, between quantum mechanics and relativity.

  2. This argument is discussed in detail by Maudlin [37, 3rd edn, pp. 128–132].

  3. For the proofs of nonlocality, it will be sufficient to consider finite dimensional spaces, which allows us to avoid all mathematical subtleties.

  4. The correlations mentioned here are often called anti-correlations, for example when \({\tilde{O}}=-O\), as in the example of the spin in Sect. 2.

  5. This is one way to understand Bohr’s response to EPR [12], although that response was not very clear.

  6. The correct answer here being the value v(O) or \(v({\tilde{O}}')\) which is determined by the measurement of \({\tilde{O}}\) or of \( {\tilde{O}}'\).

  7. This is obvious for (4.2), a special case of (3.2.1). For (4.1) we observe that, since O is self adjoint, we can write \(O = \sum _i \lambda _i P_{\lambda _i}\) where \(P_{\lambda _i}\) is the projector on the subspace of eigenvectors of eigenvalue \(\lambda _i\) of O and thus we have that \(f(O) = \sum _i f(\lambda _i) P_{\lambda _i}\). If we choose any f whose range is the set of eigenvalues of O and is such that \(f(\lambda _i)= \lambda _i\)\(\forall i\), we have that \(O=f(O)\) and, by (3.2.1), we obtain that \(v(O)=v(f(O))=f(v(O))\) and thus v(O) is an eigenvalue of O.

  8. This is not quite true. For the choice \(f(x, y)=xy\) we must have \(\dim \mathcal{H} \ge 4\).

  9. In their original argument, Kochen and Specker used 117 such sets [35], but that number was reduced to 33 by Peres [41, 42].

  10. See [4] for the original inequalities and [30] for a detailed discussion of them. For a simple version of those inequalities see [22] or [14, Chap. 4].

  11. For elementary introductions to that theory, see [15, 47] and for more advanced ones, see [8, 10, 11, 14, 21, 23, 24, 31, 40]. There are also pedagogical videos made by students in Munich, available at: https://cast.itunes.uni-muenchen.de/vod/playlists/URqb5J7RBr.html.

  12. One might object that adherents of the “Many-Worlds Interpretation” of quantum mechanics [20, 27] do not share that view, since, for them, experiments do not have a single outcome. But they nevertheless agree that measuring devices indicate definite results in each World.

  13. Here, “determinism” refers to the idea of there being pre-existing values v(A) or of the existence of a non-contextual value-map.

  14. Reference [4], reprinted as Chap. 2 in [8].

  15. In fact, this is the property that we discussed in remark 4 of Sect. 3.2, and, as Schrödinger’s example of the schoolchildren shows, it does not depend on humans having “genuine free will” (whatever that means).

  16. They also claim that their results rule out certain “spontaneous collapse theories,” a statement criticized in [3, 28, 48].

  17. Since, combined with locality, they imply the existence of a non-contextual value-map, satisfying (3.2.1) and thus also (4.14.2), whose existence is impossible because of theorem 4.1.

  18. As we mentioned in Sect. 3.2, if there exists a pre-existing value v(A), then the result of any experiment \(\mathcal{E}_A\) measuring A must be v(A).

References

  1. Albert, D.: Quantum Mechanics and Experience. Harvard University Press, Cambridge (1992)

    Google Scholar 

  2. Aravind, P.K.: Bell’s theorem without inequalities and only two distant observers. Found. Phys. Lett. 15, 399–405 (2002)

    MathSciNet  Google Scholar 

  3. Bassi, A., Ghirardi, G.C.: The Conway-Kochen argument and relativistic GRW models. Found. Phys. 37, 169–185 (2007)

    ADS  MathSciNet  MATH  Google Scholar 

  4. Bell, J.S.: On the Einstein-Podolsky-Rosen paradox. Physics 1, 195–200 (1964). Reprinted as Chap. 2 in [8]

    MathSciNet  Google Scholar 

  5. Bell, J.S.: On the problem of hidden variables in quantum mechanics. Rev. Mod. Phys. 38, 447–452 (1966). Reprinted as Chap. 1 in [8]

    ADS  MathSciNet  MATH  Google Scholar 

  6. Bell, J.S.: Bertlmann’s socks and the nature of reality. J. Phys. 42(C2), 41–61 (1981). Reprinted as Chap. 16 in [8]

    Google Scholar 

  7. Bell, J.S.: On the impossible pilot wave. Found. Phys. 12, 989–999 (1982). Reprinted as Chap. 17 in [8]

    ADS  MathSciNet  Google Scholar 

  8. Bell, J.S.: Speakable and Unspeakable in Quantum Mechanics. Collected Papers on Quantum Philosophy, 2nd edn, with an introduction by Alain Aspect. Cambridge University Press, Cambridge, 2004; 1st edn (1987)

  9. Bohm, D.: Quantum Theory, New edition. Dover, New York (1989). First edition: Prentice Hall, Englewood Cliffs (NJ), 1951

    Google Scholar 

  10. Bohm, D.: A suggested interpretation of the quantum theory in terms of “hidden variables”, Parts 1 and 2. Phys. Rev. 89, 166–193 (1952). Reprinted in [49] pp. 369–390

  11. Bohm, D., Hiley, B.J.: The Undivided Universe. Routledge, London (1993)

    MATH  Google Scholar 

  12. Bohr, N.: Can quantum-mechanical description of physical reality be considered complete? Phys. Rev. 48, 696–702 (1935)

    ADS  MATH  Google Scholar 

  13. Bohr, N.: Discussion with Einstein on epistemological problems in atomic physics. In: Schilpp, P.A. (ed.) Albert Einstein, Philosopher-Scientist, pp. 201–241. The Library of Living Philosophers, Evanston (1949)

    Google Scholar 

  14. Bricmont, J.: Making Sense of Quantum Mechanics. Springer, Berlin (2016)

    MATH  Google Scholar 

  15. Bricmont, J.: Quantum Sense and Nonsense. Springer, Basel (2017)

    MATH  Google Scholar 

  16. Brown, H.R., Svetlichny, G.: Nonlocality and Gleason’s lemma. Part I: Deterministic theories. Found. Phys. 20, 1379–1386 (1990)

    ADS  MathSciNet  Google Scholar 

  17. Cabello, A.: Bell’s theorem without inequalities and without probabilities for two observers. Phys. Rev. Lett. 86, 1911–1914 (2001)

    ADS  MathSciNet  Google Scholar 

  18. Conway, J. H., Kochen, S.: The free will theorem. Found. Phys. 36, 1441–1473 (2006); Reply to comments of Bassi, Ghirardi, and Tumulka on the free will theorem. Found. Phys. 37, 1643–1647 (2007); The strong free will theorem. Not. Am. Math. Soc.56, 226–232 (2009); The free will theorem. Series of 6 public lectures delivered by J. Conway at Princeton University, March 23–April 27, 2009. http://www.math.princeton.edu/facultypapers/Conway/

  19. Daumer, M., Dürr, D., Goldstein, S., Zanghì, N.: Naive realism about operators. Erkenntnis 45, 379–397 (1996)

    MathSciNet  MATH  Google Scholar 

  20. DeWitt, B., Graham, R.N. (eds.): The Many-Worlds Interpretation of Quantum Mechanics. Princeton University Press, Princeton (1973)

    Google Scholar 

  21. Dürr, D., Goldstein, S., Zanghì, N.: Quantum equilibrium and the origin of absolute uncertainty. J. Stat. Phys. 67, 843–907 (1992)

    ADS  MathSciNet  MATH  Google Scholar 

  22. Dürr, D., Goldstein, S., Tumulka, R., Zanghì, N.: John Bell and Bell’s theorem. In: Borchert, D.M. (ed.) Encyclopedia of Philosophy. Macmillan, New York (2005)

    MATH  Google Scholar 

  23. Dürr, D., Teufel, S.: Bohmian Mechanics. The Physics and Mathematics of Quantum Theory. Springer, Berlin (2009)

    MATH  Google Scholar 

  24. Dürr, D., Goldstein, S., Zanghì, N.: Quantum Physics Without Quantum Philosophy. Springer, Berlin (2012)

    MATH  Google Scholar 

  25. Einstein, A., Podolsky, B., Rosen, N.: Can quantum-mechanical description of physical reality be considered complete? Phys. Rev. 47, 777–780 (1935)

    ADS  MATH  Google Scholar 

  26. Elby, A.: Nonlocality and Gleason’s Lemma. Part 2. Found. Phys. 20, 1389–1397 (1990)

    ADS  MathSciNet  Google Scholar 

  27. Everett, H.: ‘Relative state’ formulation of quantum mechanics. Rev. Mod. Phys. 29, 454–462 (1957). Reprinted in [20, pp. 141–149]

    ADS  MathSciNet  Google Scholar 

  28. Goldstein, S., Tausk, D.V., Tumulka, R., Zanghì, N.: What does the free will theorem actually prove? Not. Am. Math. Soc. 57, 1451–1453 (2010)

    MathSciNet  MATH  Google Scholar 

  29. Goldstein, S.: Bohmian mechanics and quantum information. Found. Phys. 40, 335–355 (2010)

    ADS  MathSciNet  MATH  Google Scholar 

  30. Goldstein, S., Norsen, T., Tausk, D.V., Zanghì, N.: Bell’s theorem. Scholarpedia 6(10), 8378 (2011)

    ADS  Google Scholar 

  31. Goldstein, S.: Bohmian mechanics. In: E.N. Zalta (ed.) The Stanford Encyclopedia of Philosophy. Spring 2013 Edition. plato.stanford.edu/archives/spr2013/entries/qm-bohm/

  32. Hemmick, D.L.: Hidden variables and nonlocality in quantum mechanics. Doctoral thesis, Rutgers University. https://sites.google.com/site/dlhquantum/doctoral-thesis and arXiv:quant-ph/0412011v1 (1996)

  33. Hemmick, D.L., Shakur, A.M.: Bell’s Theorem and Quantum Realism. Reassessment in Light of the Schrödinger Paradox. Springer, Heidelberg (2012)

    MATH  Google Scholar 

  34. Heywood, P., Redhead, M.L.G.: Nonlocality and the Kochen-Specker paradox. Found. Phys. 13, 48–499 (1983)

    MathSciNet  Google Scholar 

  35. Kochen, S., Specker, E.P.: The problem of hidden variables in quantum mechanics. J. Math. Mech. 17, 59–87 (1967)

    MathSciNet  MATH  Google Scholar 

  36. Kochen, S.: Private communication to Abner Shimony, see [34, footnote 2]

  37. Maudlin, T.: Quantum Nonlocality and Relativity. Blackwell, Cambridge, 1st edn, 1994, 3rd edn, 2011

  38. Mermin, D.: Hidden variables and the two theorems of John Bell. Rev. Mod. Phys. 65, 803–815 (1993)

    ADS  MathSciNet  Google Scholar 

  39. Nielsen, M.A., Chuang, I.L.: Quantum Computation and Quantum Information. Cambridge University Press, Cambridge (2000)

    MATH  Google Scholar 

  40. Norsen, T.: Foundations of Quantum Mechanics: An Exploration of the Physical Meaning of Quantum Theory. Springer, Basel (2017)

    MATH  Google Scholar 

  41. Peres, A.: Incompatible results of quantum measurements. Phys. Lett. A 151, 107–108 (1990)

    ADS  MathSciNet  Google Scholar 

  42. Peres, A.: Two simple proofs of the Kochen-Specker theorem. J. Phys. A 24, L175–L178 (1991)

    ADS  MathSciNet  MATH  Google Scholar 

  43. Schrödinger, E.: Die gegenwärtige Situation in der Quantenmechanik, Naturwissenschaften 23, 807–812; 823–828; 844–849 (1935). English translation: The present situation in quantum mechanics, translated by J.D. Trimmer, Proceedings of the American Philosophical Society 124, 323–338 (1980). Reprinted. In: Wheeler, J.A., Zurek, W.H. (eds.) Quantum Theory and Measurement. Princeton University Press, Princeton, 152–167 (1983)

  44. Schrödinger, E.: Discussion of probability relations between separated systems. Math. Proc. Cambrid. Philos. Soc. 31, 555–563 (1935)

    ADS  MATH  Google Scholar 

  45. Schrödinger, E.: Probability relations between separated systems. Math. Proc. Camb. Philos. Soc. 32, 446–452 (1936)

    ADS  MATH  Google Scholar 

  46. Stairs, A.: Quantum logic, realism and value-definiteness. Philos. Sci. 50, 578–602 (1983)

    MathSciNet  MATH  Google Scholar 

  47. Tumulka, R.: Understanding Bohmian mechanics—a dialogue. Am. J. Phys. 72, 1220–1226 (2004)

    ADS  Google Scholar 

  48. Tumulka, R.: Comment on “The Free Will Theorem”. Found. Phys. 37, 186–197 (2007)

    ADS  MathSciNet  MATH  Google Scholar 

  49. Wheeler, J.A., Zurek, W.H. (eds.): Quantum Theory and Measurement. Princeton University Press, Princeton (1983)

    Google Scholar 

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Correspondence to Jean Bricmont.

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Communicated by Giovanni Gallavotti.

Dedicated to our mentor, Joel L. Lebowitz, a master of statistical physics who, when it came to foundational issues of quantum mechanics, was always willing to listen.

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Bricmont, J., Goldstein, S. & Hemmick, D. Schrödinger’s Paradox and Proofs of Nonlocality Using Only Perfect Correlations. J Stat Phys 180, 74–91 (2020). https://doi.org/10.1007/s10955-019-02361-w

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