The Unspeakable Why

  • Adán Cabello
Part of the The Frontiers Collection book series (FRONTCOLL)


For years, the biggest unspeakable in quantum theory has been why quantum theory and what is quantum theory telling us about the world. Recent efforts are unveiling a surprisingly simple answer. Here we show that two characteristic limits of quantum theory, the maximum violations of Clauser-Horne-Shimony-Holt and Klyachko-Can-Binicioğlu-Shumovsky inequalities, are enforced by a simple principle. The effectiveness of this principle suggests that non-realism is the key that explains why quantum theory.


Quantum Theory Hide Variable Joint Probability Distribution Bell Inequality Quantum Probability 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.



This work was supported by the project FIS2011-29400 (MINECO, Spain) with FEDER funds, the FQXi large grant project “The Nature of Information in Sequential Quantum Measurements” and the program Science without Borders (CAPES and CNPq, Brazil).


  1. 1.
    J.S. Bell, Physics (Long Island City, N.Y.) 1, 195 (1964)Google Scholar
  2. 2.
    J.F. Clauser, M.A. Horne, A. Shimony, R.A. Holt, Phys. Rev. Lett. 23, 880 (1969)ADSCrossRefGoogle Scholar
  3. 3.
    B.S. Cirel’son [Tsirelson], Lett. Math. Phys. 4, 93 (1980)Google Scholar
  4. 4.
    S. Popescu, D. Rohrlich, Found. Phys. 24, 379 (1994)ADSMathSciNetCrossRefGoogle Scholar
  5. 5.
    M. Pawłowski, T. Paterek, D. Kaszlikowski, V. Scarani, A. Winter, M. Żukowski, Nature 461, 1101 (2009)ADSCrossRefGoogle Scholar
  6. 6.
    T.H. Yang, D. Cavalcanti, M.L. Almeida, C. Teo, V. Scarani, New J. Phys. 14, 013061 (2012)CrossRefGoogle Scholar
  7. 7.
    M. Jammer, The Philosophy of Quantum Mechanics (Wiley, New York, 1974)Google Scholar
  8. 8.
    M. Jammer, Found. Phys. 20, 1139 (1990)ADSCrossRefGoogle Scholar
  9. 9.
    J.S. Bell, Rev. Mod. Phys. 38, 447 (1966)ADSCrossRefGoogle Scholar
  10. 10.
    A.M. Gleason, J. Math. Mech. 6, 885 (1957)MathSciNetGoogle Scholar
  11. 11.
    S. Kochen, in E. Engeler, N. Hungerbühler, and J.A. Makowsky (eds.), Elem. Math. 67, 1 (2012)Google Scholar
  12. 12.
    S. Kochen, E.P. Specker, J. Math. Mech. 17, 59 (1967)MathSciNetGoogle Scholar
  13. 13.
    E.P. Specker, Dialectica 14, 239 (1960). English translation: arXiv:1103.4537
  14. 14.
    A.A. Klyachko, M.A. Can, S. Binicioğlu, A.S. Shumovsky, Phys. Rev. Lett. 101, 020403 (2008)ADSMathSciNetCrossRefGoogle Scholar
  15. 15.
    M. Kleinmann, J. Phys. A: Math. Theor. 47, 455304 (2014)ADSMathSciNetCrossRefGoogle Scholar
  16. 16.
    G. Chiribella, X. Yuan, arXiv:1404.3348
  17. 17.
    J. von Neumann, Mathematische Grundlagen der Quantenmechanik (Springer-Verlag, Berlin, 1932) (Mathematical Foundations of Quantum Mechanics (Princeton University Press, Princeton, New Jersey, 1955)Google Scholar
  18. 18.
    A. Cabello, Phys. Rev. Lett. 110, 060402 (2013)Google Scholar
  19. 19.
    H. Barnum, M. P. Müller, C. Ududec, New J. Phys. 16, 123029 (2014)Google Scholar
  20. 20.
    J. Henson, Phys. Rev. Lett. 114, 220403 (2015)Google Scholar
  21. 21.
    A. Cabello, Phys. Rev. A 90, 062125 (2014)ADSCrossRefGoogle Scholar
  22. 22.
    A. Cabello, Phys. Rev. Lett. 114, 220402 (2015)Google Scholar
  23. 23.
    A. Cabello (in preparation)Google Scholar
  24. 24.
    N. Gisin, Found. Phys. 42, 80 (2012)ADSMathSciNetCrossRefGoogle Scholar

Copyright information

© Springer International Publishing Switzerland 2017

Authors and Affiliations

  1. 1.Departamento de Física Aplicada IIUniversidad de SevillaSevillaSpain

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