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‘Observational’ Quantum Cosmology

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Book cover Quantum Cosmology - The Supersymmetric Perspective - Vol. 2

Part of the book series: Lecture Notes in Physics ((LNP,volume 804))

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Abstract

Following on the appraisal presented in Chap. 2 of Vol. I, the reader may rightfully be asking: Given the framework of quantum cosmology (QC), where are the boundaries of our knowledge, i.e., what exactly constitutes these limits? What are the best directions to move in, and in particular, what predictions or (falsifiable) tests for the universe can be made using quantum cosmology?

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Notes

  1. 1.

    For the momentum constraints (2.2) at this order, we obtain

    $$h_{ij}{\,^{(3)}\nabla}_k\left({\frac{\updelta{{S_0}}}{\updelta{{h_{ik}}}}}\right)=0\;.$$
    ((2.7))
  2. 2.

    Every solution of (2.8) determines a family of solutions of the classical field equations. Equations (2.7) and (2.8) are equivalent to Einstein’s field equations.

  3. 3.

    Up to this order, the total wave functional thus reads

    $$\varPsi\approx\frac{1}{\mathcal{K}}\exp\left({{\textrm i}} \textbf{M}S_0[h_{ab}]/\hbar \right) {\mathcal{F}} [h_{ab},\phi]\;,$$
    ((2.12))

    where \({\mathcal{F}}\) satisfies the Schrödinger equation.

  4. 4.

    ‘Time’ is thus defined through the chosen solution S 0 of the Hamilton–Jacobi equation. However, \(\boldsymbol{\tau}\) is not a spacetime scalar. Nevertheless, the semi-classical scheme can be implemented with the (functional) Schrödinger equation found by integrating (2.14) over three-dimensional space.

  5. 5.

    Note that \(\breve{\sigma}_2\) is a pure gravitational term.

  6. 6.

    Minisuperspace coordinates \(q^X\) are treated as (semi)classical, while the perturbations constitute quantum mechanical quantitities.

  7. 7.

    Compare with the Born–Oppenheimer approximation, where ignoring the off-diagonal terms amounts to assuming a decoherence process.

References

  • Barvinsky, A.O., Kamenshchik, A.Yu., Kiefer, C., Mishakov, I.V.: Decoherence in quantum cosmology at the onset of inflation. Nucl. Phys. B 551, 374–396 (1999)

    Article  ADS  Google Scholar 

  • Barvinsky, A.O., Kamenshchik, A.Yu., Kiefer, C.: Effective action and decoherence by fermions in quantum cosmology. Nucl. Phys. B 552, 420–444 (1999)

    Article  MathSciNet  ADS  MATH  Google Scholar 

  • Barvinsky, A.O., Kiefer, C.: Wheeler–DeWitt equation and Feynman diagrams. Nucl. Phys. B 526, 509–539 (1998)

    Article  MathSciNet  ADS  MATH  Google Scholar 

  • Giulini, D., et al.: Decoherence and the Appearance of a Classical World in Quantum Theory, p. 366. Springer, Heidelberg (1996)

    Book  MATH  Google Scholar 

  • Giulini, D., Kiefer, C., Zeh, H.D.: Symmetries, superselection rules, and decoherence. Phys. Lett. A 199, 291–298 (1995)

    Article  MathSciNet  ADS  MATH  Google Scholar 

  • Giulini, D., Kiefer, C.: Consistency of semiclassical gravity. Class. Quant. Grav. 12, 403–412 (1995)

    Article  MathSciNet  ADS  Google Scholar 

  • Giulini, D., Kiefer, C., Lammerzahl, C. (eds.): Quantum Gravity: From Theory to Experimental Search, p. 400. Springer, Heidelberg (2003)

    Google Scholar 

  • Kiefer, C.: Decoherence in quantum electrodynamics and quantum gravity. Phys. Rev. D 46, 1658–1670 (1992)

    Article  ADS  Google Scholar 

  • Kiefer, C.: Quantum Gravity. International Series of Monographs on Physics, vol. 136, 2nd edn., pp. 1–308. Clarendon Press, Oxford (2007)

    Book  Google Scholar 

  • Kiefer, C.: Continuous measurement of minisuperspace variables by higher multipoles. Class. Quant. Grav. 4, 1369 (1987)

    Article  MathSciNet  ADS  Google Scholar 

  • Kiefer, C.: Continuous measurement of intrinsic time by fermions. Class. Quant. Grav. 6, 561 (1989)

    Article  MathSciNet  ADS  Google Scholar 

  • Kiefer, C.: How does quantum gravity modify the Schrödinger equation for matter fields? Class. Quant. Grav. 9, S147–S156 (1992)

    Article  MathSciNet  ADS  Google Scholar 

  • Kiefer, C., Polarski, D.: Emergence of classicality for primordial fluctuations: Concepts and analogies. Annalen Phys. 7, 137–158 (1998)

    Article  ADS  MATH  Google Scholar 

  • Kiefer, C., Polarski, D., Starobinsky, A.A.: Quantum-to-classical transition for fluctuations in the early universe. Int. J. Mod. Phys. D 7, 455–462 (1998)

    Article  ADS  MATH  Google Scholar 

  • Kiefer, C., Singh, T.P.: Quantum gravitational corrections to the functional Schrödinger equation. Phys. Rev. D 44, 1067–1076 (1991)

    Article  MathSciNet  ADS  Google Scholar 

  • Kiefer, C., Luck, T., Moniz, P.: The semiclassical approximation to supersymmetric quantum gravity. Phys. Rev. D 72, 045006 (2005)

    Article  MathSciNet  ADS  Google Scholar 

  • Moniz, P.V.: Origin of structure in a supersymmetric quantum universe. Phys. Rev. D 57, 7071–7074 (1998)

    Article  MathSciNet  ADS  Google Scholar 

  • Kiefer, C.: The semiclassical approximation to quantum gravity. gr-qc/9312015 (1993)

    Google Scholar 

  • Halliwell, J.J., Hawking, S.W.: The origin of structure in the universe. Phys. Rev. D 31, 1777 (1985)

    Article  MathSciNet  ADS  Google Scholar 

  • Halliwell, J.J.: Introductory lectures on quantum cosmology. In: Proceedings of Jerusalem Winter School on Quantum Cosmology and Baby Universes, Jerusalem, Israel, 27 December 1989–4 January 1990

    Google Scholar 

  • Padmanabhan, T., Singh, T.P.: On the semiclassical limit of the Wheeler–DeWitt equation. Class. Quant. Grav. 7, 411–426 (1990)

    Article  MathSciNet  ADS  Google Scholar 

  • Wiltshire, D.L.: An introduction to quantum cosmology. In: Robson, B., Visvanathan, N., Woolcock, W.S. (eds.) Cosmology: The Physics of the Universe, Proceedings of the 8th Physics Summer School, A.N.U., January–February 1995, pp. 473–531. World Scientific, Singapore (1996). gr-qc/0101003 (1995)

    Google Scholar 

  • Birrell, N.D., Davies, P.C.W.: Quantum Fields in Curved Space, p. 340. Cambridge University Press, Cambridge (1982)

    Book  MATH  Google Scholar 

  • Bertolami, O., Moniz, P.V.: Decoherence of Friedmann–Robertson–Walker geometries in the presence of massive vector fields with U(1) or SO(3) global symmetries. Nucl. Phys. B 439, 259–290 (1995)

    Article  MathSciNet  ADS  MATH  Google Scholar 

  • Hu, B.L., Verdaguer, E.: Stochastic gravity: Theory and applications. Living Rev. Rel. 11, 3 (2008)

    Google Scholar 

  • Hu, B.L., Sinha, S.: A fluctuation–dissipation relation for semiclassical cosmology. Phys. Rev. D 51, 1587–1606 (1995)

    Article  MathSciNet  ADS  Google Scholar 

  • Sinha, S., Hu, B.L.: Validity of the minisuperspace approximation: An example from interacting quantum field theory. Phys. Rev. D 44, 1028–1037 (1991)

    Article  ADS  Google Scholar 

  • Bouhmadi-López, M., Moniz, P.V.: Quantisation of parameters and the string landscape problem. hep-th/0612149 (2006)

    Google Scholar 

  • Bousso, R.: Precision cosmology and the landscape. hep-th/0610211 (2006)

    Google Scholar 

  • Hartle, J.B., Hawking, S.W.: Wave function of the universe. Phys. Rev. D 28, 2960–2975 (1983)

    Article  MathSciNet  ADS  Google Scholar 

  • Vilenkin, A.: Quantum creation of universes. Phys. Rev. D 30, 509–511 (1984)

    Article  MathSciNet  ADS  Google Scholar 

  • Vilenkin, A.: Creation of universes from nothing. Phys. Lett. B 117, 25 (1982)

    Article  MathSciNet  ADS  Google Scholar 

  • Vilenkin, A.: Boundary conditions in quantum cosmology. Phys. Rev. D 33, 3560 (1986)

    Article  MathSciNet  ADS  Google Scholar 

  • Vilenkin, A.: Quantum cosmology and the initial state of the universe. Phys. Rev. D 37, 888 (1988)

    Article  MathSciNet  ADS  Google Scholar 

  • Vilenkin, A.: Approaches to quantum cosmology. Phys. Rev. D 50, 2581–2594 (1994)

    Article  MathSciNet  ADS  Google Scholar 

  • Page, D.N.: Lectures on quantum cosmology. In: Mann, R.B., et al. (eds.) Proceedings of Banff Summer Institution on Gravitation, Banff, Canada, 12–15 August 1990, pp. 135–170. World Scientific, Singapore (1991)

    Google Scholar 

  • Page, D.N.: Quantum cosmology lectures. gr-qc/9507028 (1994)

    Google Scholar 

  • Page, D.N.: Aspects of quantum cosmology. gr-qc/9507025 (1995)

    Google Scholar 

  • Page, D.N.: Quantum cosmology. hep-th/0610121 (2002)

    Google Scholar 

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Correspondence to Paulo Vargas Moniz .

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Moniz, P.V. (2010). ‘Observational’ Quantum Cosmology. In: Quantum Cosmology - The Supersymmetric Perspective - Vol. 2. Lecture Notes in Physics, vol 804. Springer, Berlin, Heidelberg. https://doi.org/10.1007/978-3-642-11570-7_2

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