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Quantum mechanics from stochastic processes

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Abstract

We construct an explicit one-to-one correspondence between non-relativistic stochastic processes and solutions of the Schrödinger equation and between relativistic stochastic processes and solutions of the Klein–Gordon equation. The existence of this equivalence suggests that the Lorentzian path integral can be defined as an Itô integral, similar to the definition of the Euclidean path integral in terms of the Wiener integral. Moreover, the result implies a stochastic interpretation of quantum theories.

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Notes

  1. For \(\alpha \in (0,\infty )\) one obtains the heat equation and for \(\alpha \in (-\infty ,0)\) the time-reversed heat equation.

  2. For \(\alpha \in \textrm{i}\times (0,\infty )\) one obtains the Schrödinger equation and for \(\alpha \in \textrm{i}\times (-\infty ,0)\) the time-reversed Schrödinger equation.

  3. Starting in Sect. 9, we will generalize this to pseudo-Riemannian manifolds \((\mathcal {M},g)\).

  4. The statistical theory is often referred to as the Euclidean theory as the Wick rotation does not only change the value of the diffusion constant, but also the signature of the spacetime.

  5. The presence of this divergent term resolves Wallstrom’s criticism of stochastic mechanics [23, 24].

  6. We stress that the complex process studied here is different from the processes that were previously studied in stochastic mechanics [13,14,15,16,17], including the complex formulation due to Pavon [18, 19]. The advantage of this reformulation is twofold: (i) the complex process unifies quantum mechanics (\(\alpha =\textrm{i}\)) and Brownian motion (\(\alpha =1\)) in a single framework; (ii) the complex process correctly reproduces all aspects of quantum mechanics, whereas previous formulations failed to recover the correct multi-time correlations [20].

  7. In non-relativistic theories the evolution parameter is the time t, while in relativistic theories the time t is promoted to a coordinate \(x^0=c\,t\). Instead, the evolution of relativistic dynamics is defined with respect to an arbitrary affine parameter \(\lambda\). If \(m>0\), this parameter reduces to the proper time \(\tau\) of the particle after gauge fixing \(\varepsilon\).

  8. This is not the first work to point this out, as relativistic quantum theories for a single particle have been developed earlier in the literature, cf. e.g. Ref. [28].

  9. \(\Psi\) is the solution of a complex diffusion equation on the space \(\mathcal {M}\times \mathcal {T}\), where the dynamics is measured with respect to the affine parameter \(\lambda\). Due to the reparameterization invariance of the relativistic theory, this diffusion equation can be solved by separation of variables, yielding Eq. (78), where \(\Phi\) satisfies the Klein-Gordon equation (79).

References

  1. R.P. Feynman, Space-time approach to nonrelativistic quantum mechanics. Rev. Mod. Phys. 20, 367–387 (1948)

    Article  ADS  MATH  Google Scholar 

  2. K. Itô, Stochastic integral. Proc. Imp. Acad. Tokyo 20, 519–524 (1944)

    MathSciNet  MATH  Google Scholar 

  3. B. Mandelbrot, An outline of a purely phenomenological theory of statistical thermodynamics-I: canonical ensembles. IEEE Trans. Inform. Theory 2, 190–203 (1956)

    Article  Google Scholar 

  4. T. Koide, T. Kodama, Generalization of uncertainty relation for quantum and stochastic systems. Phys. Lett. A 382, 1472–1480 (2018)

    Article  ADS  MathSciNet  MATH  Google Scholar 

  5. P. Biane, Itô’s stochastic calculus and Heisenberg commutation relations. Stoch. Process. Their Appl. 120, 698–720 (2010)

    Article  MATH  Google Scholar 

  6. N. Wiener, Differential space. J. Math. Phys. 58, 131–174 (1923)

    Article  MathSciNet  MATH  Google Scholar 

  7. I.M. Gelfand, A.M. Yaglom, Integration in functional spaces and its applications in quantum physics. J. Math. Phys. 1, 48 (1960)

    Article  ADS  MathSciNet  MATH  Google Scholar 

  8. M. Kac, On distributions of certain wiener functionals. Trans. Amer. Math. Soc. 65, 1–13 (1949)

    Article  MathSciNet  MATH  Google Scholar 

  9. R.H. Cameron, A family of integrals serving to connect the Wiener and Feynman integrals. J. Math. and Phys. 39, 126–140 (1960)

    Article  MathSciNet  MATH  Google Scholar 

  10. Yu.L. Daletskii, Functional integrals connected with operator evolution equations. Russ. Math. Surv. 17(5), 1–107 (1962)

    Article  Google Scholar 

  11. J. Glimm, A.M. Jaffe, Quantum physics: a functional integral point of view (Springer, New York, 1987)

    Book  MATH  Google Scholar 

  12. G.C. Wick, Properties of Bethe-Salpeter wave functions. Phys. Rev. 96, 1124–1134 (1954)

    Article  ADS  MathSciNet  MATH  Google Scholar 

  13. E. Nelson, Dynamical theories of brownian motion (Princeton University Press, Princeton, 1967)

    Book  MATH  Google Scholar 

  14. I. Fényes, Eine Wahrscheinlichkeitstheoretische Begründung und Interpretation der Quantenmechanik. Zeitschrift für Physik 132, 81 (1952)

    Article  ADS  MathSciNet  MATH  Google Scholar 

  15. E. Nelson, Derivation of the Schrodinger equation from Newtonian mechanics. Phys. Rev. 150, 1079–1085 (1966)

    Article  ADS  Google Scholar 

  16. E. Nelson, Quantum fluctuations (Princeton University Press, Princeton, 1985)

    Book  MATH  Google Scholar 

  17. F. Guerra, Structural aspects of stochastic mechanics and stochastic field theory. Phys. Rept. 77, 263–312 (1981)

    Article  ADS  MathSciNet  Google Scholar 

  18. M. Pavon, A new formulation of stochastic mechanics. Phys. Lett. A 209, 143–149 (1995)

    Article  ADS  MathSciNet  MATH  Google Scholar 

  19. M. Pavon, Stochastic mechanics and the Feynman integral. J. Math. Phys. 41, 6060 (2000)

    Article  ADS  MathSciNet  MATH  Google Scholar 

  20. E. Nelson, Review of stochastic mechanics. J. Phys. Conf. Ser. 361, 012011 (2012)

    Article  Google Scholar 

  21. F. Kuipers, Stochastic Mechanics: the Unification of Quantum Mechanics with Brownian Motion, Briefs in Physics (Springer, Cham, 2023)

    Book  Google Scholar 

  22. P. Lévy, Processus stochastiques et mouvement brownien (Gauthier-Villars, Paris, 1948)

    MATH  Google Scholar 

  23. T.C. Wallstrom, On the derivation of the Schrödinger equation from stochastic mechanics. Found. Phys. Lett. 2(2), 113 (1988)

    Article  MathSciNet  Google Scholar 

  24. T.C. Wallstrom, Inequivalence between the Schrödinger equation and the Madelung hydrodynamic equations. Phys. Rev. A 49(3), 1613 (1993)

    Article  ADS  MathSciNet  Google Scholar 

  25. J.C. Zambrini, Stochastic dynamics: a review of stochastic calculus. Int. J. Theor. Phys. 24(3), 277 (1985)

    Article  MathSciNet  MATH  Google Scholar 

  26. Q. Huang, J. C. Zambrini, From second-order differential geometry to stochastic geometric mechanics, arXiv:2201.03706 [math-ph] (2022)

  27. M.E. Peskin, D.V. Schroeder, An introduction to quantum field theory (Addison-Wesley, Melbourne, 1995)

    Google Scholar 

  28. M. Reisenberger, C. Rovelli, Space-time states and covariant quantum theory. Phys. Rev. D 65, 125016 (2002)

    Article  ADS  MathSciNet  Google Scholar 

  29. P.A. Meyer, A differential geometric formalism for the Itô calculus Stochastic Integrals Lecture Notes in Mathematics, vol. 851 (Springer, Berlin and Heidelberg, 1981)

    Google Scholar 

  30. L. Schwartz, Semi-martingales and their stochastic calculus on manifolds (Presses de l’Université de Montréal, Montreal, 1984)

    Google Scholar 

  31. M. Emery, Stochastic calculus in manifolds (Springer, Berlin & Heidelberg, 1989)

    Book  MATH  Google Scholar 

  32. B.S. DeWitt, Dynamical theory in curved spaces I: a review of the classical and quantum action principles. Rev. Mod. Phys. 29, 377–397 (1957)

    Article  ADS  MathSciNet  MATH  Google Scholar 

  33. W. Pauli, Pauli lectures on physics 6: selected topics in field quantization (MIT press, Cambridge, 1973)

    Book  Google Scholar 

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Acknowledgements

This research was carried out in the frame of Programme STAR Plus, financially supported by UniNA and Compagnia di San Paolo.

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Correspondence to Folkert Kuipers.

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Kuipers, F. Quantum mechanics from stochastic processes. Eur. Phys. J. Plus 138, 542 (2023). https://doi.org/10.1140/epjp/s13360-023-04184-x

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