Quantum Origin of Cosmological Structure and Dynamical Reduction Theories

Daniel Sudarsky

doi:10.1017/9781316535783.018

17 - Quantum Origin of Cosmological Structure and Dynamical Reduction Theories

from Part IV - Quantum Foundations and Quantum Gravity

Published online by Cambridge University Press: 18 April 2017

Edited by

John D. Barrow and

Daniel Sudarsky: Affiliation:
Universidad Nacional Autónoma de México, México
Khalil Chamcham: Affiliation:
University of Oxford
Joseph Silk: Affiliation:
University of Oxford
John D. Barrow: Affiliation:
University of Cambridge
Simon Saunders: Affiliation:
University of Oxford

Book contents

Get access

Summary

Introduction

Contemporary cosmology includes inflation as one of its central components. It corresponds to a period of accelerated expansion thought to have occurred very early in cosmic history, which takes the universe from relatively generic post Planckian era conditions to a stage where it is well described (with exponential accuracy in the number of e-folds) by a flat Robertson–Walker space-time (which describes a homogeneous and isotropic cosmology).

It was initially proposed to resolve various naturalness problems: flatness, horizons, and the excess of massive relic objects, such as topological defects, that were expected to populate the universe according to grand unified theories (GUT). Nowadays, it is lauded because it predicts that the universe's mean density should be essentially identical to the critical value, a very peculiar situation which corresponds to a spatially flat universe. The existing data support this prediction. However, its biggest success is claimed to be the natural account for the emergence of the seeds of cosmic structure in terms of primordial quantum fluctuations, and the correct estimate of the corresponding microwave spectrum.

This represents, thus, a situation which requires the combined application of general relativity (GR) and quantum theory, and that, moreover, is tied with observable imprints left from the early universe, in both the radiation in cosmic microwave background (CMB), and in the large scale cosmological structure we can observe today. It should not be surprising that, when dealing with attempts to apply our theories to the universe as a whole, we should come face to face with some of the most profound conceptual problems facing our current physical ideas.

In fact, J. Hartle had noted long ago [28] that serious difficulties must be faced when attempting to apply quantum theory to cosmology, although the situations that were envisioned in those early works corresponded to the even more daunting problem of full quantum cosmology, and not the limited use of quantum theory to consider perturbative aspects, which is what is required in the treatment of the inflationary origin of the seeds of cosmic structure. This led him and his collaborators to consider the Consistent Histories framework, which is claimed to offer a version of quantum theory that does not rely on any fundamental notion of measurements, as the favored approach to use in such contexts. We will have a bit more to say about this shortly.

Type: Chapter
Information: The Philosophy of Cosmology , pp. 330 - 355

DOI: https://doi.org/10.1017/9781316535783.018 [Opens in a new window]

Publisher: Cambridge University Press

Print publication year: 2017

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

[1] Bassi, A., Ippoliti, E., and Vacchini, B. 2005. On the energy increase in space-collapse models. Journal of Physics A: Mathematical and General. 38(37), 8017.Google Scholar

[2] Bedingham, D. J. 2011. Relativistic state reduction dynamics. Found. Phys.. 41, 686– 704.Google Scholar

[3] Bombelli, L., Lee, J., Meyer, D. and Sorkin, R. 1987. Space-Time as a Causal Set. Phys. Rev. Lett.. 59, 521–4.Google Scholar

[4] Cañate, P., Pearle, P. and Sudarsky, D. 2013. Continuous spontaneous localization wave function collapse model as a mechanism for the emergence of cosmological asymmetries in inflation. Phys. Rev.. D87(10), 104024.Google Scholar

[5] Carlip, S. 2008. Is Quantum Gravity Necessary? Class. Quant. Grav.. 25, 154010.Google Scholar

[6] Castagnino, M., Fortin, S., Laura, R. and Sudarsky, D. 2014. Interpretations of Quantum Theory in the Light of Modern Cosmology. (2014) arXiv:1412.75756.

[7] Das, S., Lochan, K., Sahu, S. and Singh, T. P. 2013. Quantum to classical transition of inflationary perturbations: Continuous spontaneous localization as a possible mechanism. Phys. Rev.. D88(8), 085020.Google Scholar

[8] Diez-Tejedor, A. and Sudarsky, D. 2012. Towards a formal description of the collapse approach to the inflationary origin of the seeds of cosmic structure. JCAP. 1207, 045.Google Scholar

[9] Diosi, L. 1984. Gravitation and Quantum Mechanical Localization of Macro-Objects. Phys. Lett. A. 105, 4–5, 199–202.Google Scholar

[10] Diosi, L. 1987. A Universal Master Equation for the Gravitational Violation of Quantum Mechanics. Phys. Lett.. A120, 377.Google Scholar

[11] Diosi, L. 1989. Models for universal reduction of macroscopic quantum fluctuations. Phys. Rev., A40, 1165–1174.

[12] Diosi, L. and Lukacs, B. 1987. In Favor of a Newtonian Quantum Gravity. Annalen Phys.. 44, 488.Google Scholar

[13] Diosi, L. and Lukacs, B. 1989. On the minimum uncertainty of space-time geodesics. Phys. Lett., A142, 331.

[14] Diosi, L. 1997. Lorentz covariant stochastic wave function dynamics? arXiv:quantph/ 9704025.

[15] Diosi, L. 2000. Emergence of classicality: from collapse phenomenologies to hybrid dynamics. Lect. Notes Phys.. 538, 243–50.Google Scholar

[16] Diosi, L. 2004. Probability of intrinsic time arrow from information loss. Lect. Notes Phys.. 633, 125–35.Google Scholar

[17] Diosi, L. 2014. Gravity-related spontaneous wave function collapse in bulk matter. New J. Phys.. 16(10), 105006.Google Scholar

[18] Diosi, L. and Papp, T. N. 2009. Schrödinger–Newton equation with complex Newton constant and induced gravity. Phys. Lett., A373, 3244–7.

[19] Durr, D., Goldstein, S., Tumulka, R. and Zanghi, N. 2004. Bohmian mechanics and quantum field theory. Phys. Rev. Lett.. 93, 090402.Google Scholar

[20] Gambini, R., Porto, R. A. and Pullin, J. 2004. Fundamental decoherence from relational time in discrete quantum gravity: Galilean covariance. Phys. Rev., D70, 124001.

[21] Ghirardi, G. C., Rimini, A. and Weber, T. 1985. A model for a unified quantum description of macroscopic and microscopic systems. In Quantum Probability and Applications II, Lecture Notes in Mathematics. Vol. 1136. ISBN 978-3-540-15661-1. Springer Verlag, p. 223.

[22] Ghirardi, G. C., Rimini, A. and Weber, T. 1986. A Unified Dynamics for Micro and MACRO Systems. Phys. Rev., D34, 470.

[23] Ghirardi, G. C., Nicrosini, O., Rimini, A. and Weber, T. 1988. Spontaneous Localization of a System of Identical Particles. Nuovo Cim., B102, 383.

[24] Ghirardi, G. C., Grassi, R. and Pearle, Philip M. 1990a. Relativistic dynamical reduction models: General framework and examples. Foundations of Physics. 20, 11, 1271–316.Google Scholar

[25] Ghirardi, G. C., Pearle, P. M. and Rimini, A. 1990b. Markov Processes in Hilbert Space and Continuous Spontaneous Localization of Systems of Identical Particles. Phys. Rev., A42, 78–9.

[26] Ghirardi, G. C., Grassi, R. and Rimini, A. 1990c. A continuous spontaneous reduction model involving gravity. Phys. Rev., A42, 1057–64.

[27] Ghirardi, G. C., Grassi, R. and Pearle, P.M. 1990d. Relativistic dynamical reduction models and nonlocality. J. Found. Mod. Phys., 0109–123.

[28] Hartle, J. B. 2006. Generalizing quantum mechanics for quantum gravity. Int. J. Theor. Phys.. 45, 1390–96.Google Scholar

[29] Israel, W. 1966. Singular hypersurfaces and thin shells in general relativity. Nuovo Cim., B44S10, 1.

[30] Jacobson, T. 1995. Thermodynamics of space-time: The Einstein equation of state. Phys. Rev. Lett.. 75, 1260–63.Google Scholar

[31] Kastner, R. E. 2014. Comment on “Quantum Darwinism, Decoherence, and the Randomness of Quantum Jumps,” arxiv:1412.5206.

[32] Martin, J., Vennin, V. and Peter, P. 2012. Cosmological Inflation and the Quantum Measurement Problem. Phys. Rev., D86, 103524.

[33] Modak, S. K., Ortz, L., Pea, I., and Sudarsky, D. 2014. Black Holes: Information Loss But No Paradox. arXiv:1406.4898 [gr-qc].

[34] Mott, N. F. 1929. The Wave Mechanics of α- Ray tracks. Proc. of the Royal Soc. of. London, 126, 79.

[35] Okon, E. and Sudarsky, D. 2014. Benefits of Objective Collapse Models for Cosmology and Quantum Gravity. Foundations of Physics. 44(2), 114–3.Google Scholar

[36] Okon, E. and Sudarsky, D. 2015. The Black Hole Information Paradox and the Collapse of the Wave Function. Foundations of Physics. 45(4), 461–70.Google Scholar

[37] Page, D. N. and Geilker, C. D. 1981. Indirect Evidence for Quantum Gravity. Phys. Rev. Lett.. 47, 979–82.Google Scholar

[38] Pearle, P.M. 1984. Experimental tests of dynamical state-vector reduction. Phys. Rev., D29, 235–40.

[39] Pearle, P.M. 2014a. CollapseMiscellany. In: Struppa, D. C. and Tollaksen, J. M., eds. Quantum Theory: A Two-Time Success Story. (Milan: Springer Milan), pp. 131–56.

[40] Pearle, P. M. 1976. Reduction of the State Vector by a Nonlinear Schrodinger Equation. Phys.Rev., D13, 857–68.

[41] Pearle, P. M. 1979. Toward Explaining Why Events Occur. Int. J. Theor. Phys.. 18, 489–518.Google Scholar

[42] Pearle, P. M. 1989. Combining Stochastic Dynamical State Vector Reduction With Spontaneous Localization. Phys. Rev., A39, 2277–89.

[43] Pearle, P. M. 1999. Collapse models. Lect. Notes Phys.. 526, 195.Google Scholar

[44] Pearle, P. M. 2000. Wave function collapse and conservation laws. Found. Phys.. 30, 1145–60.Google Scholar

[45] Pearle, P. M. 2014b. A Relativistic Dynamical Collapse Model for a Scalar Field. arXiv:1404.5074.

[46] Pearle, P.M. and Squires, E. 1996. Gravity, energy conservation and parameter values in collapse models. Found. Phys.. 26, 291.Google Scholar

[47] Penrose, R. 2000. Gravitational collapse of the wavefunction: An experimentally testable proposal. Proceedings, 9th Marcel Grossman Meeting, 3–6.

[48] Penrose, R. 2001. On gravity's role in quantum state reduction. In: Callender, C., ed. Physics Meets Philosophy at the Planck Scale, pp. 290–304.

[49] Penrose, R. 1996. On gravity's role in quantum state reduction. Gen. Rel. Grav.. 28, 581–600.Google Scholar

[50] Penrose, R. 2014. On the Gravitization of Quantum Mechanics 1: Quantum State Reduction. Found. Phys.. 44, 557–5.Google Scholar

[51] Perez, A., Sahlmann, H. and Sudarsky, D. 2006. On the quantum origin of the seeds of cosmic structure. Class. Quant. Grav.. 23, 2317–54.Google Scholar

[52] Seiberg, N. 2007. Emergent spacetime. In The Quantum Structure of Space and Time. World Scientific. arXiv:hep-th/0601234.

[53] Shimony, A. 2013. Bell's Theorem. In Zalta, E. N., ed. The Stanford Encyclopedia of Philosophy, winter 2013 edn. http://plato.stanford.edu/entries/bell-theorem/.

[54] Sudarsky, D. 2011. Shortcomings in the Understanding of Why Cosmological Perturbations Look Classical. Int. J. Mod. Phys., D20, 509–52.

[55] Tumulka, R. 2006. On spontaneous wave function collapse and quantum field theory. Proc. Roy. Soc. Lond., A462, 1897–908.

[56] Weinberg, S. 2008. Cosmology. Oxford University Press.

[57] Weinberg, S. 2012. Collapse of the State Vector. Phys. Rev., A85, 062116.

[58] Zurek, W. H. (2016) Quantum Darwinism, Decoherence, and the Randomness of Quantum Jumps. Physics Today. 67, 10, 44–50.Google Scholar

[59] Zurek, W. H. 1998. Decoherence, Einselection, and the existential interpretation: The Rough guide. Phil. Trans. Roy. Soc. Lond., A356, 1793–820.

[60] Valentine, A. 2010. Phys. Rev., D82, 063513, 43pp.

[61] Pinto-Neto, N., Santos, G. and Struyve, W. 2012. Phys. Rev., D85, 083506, 4pp.

Book contents

17 - Quantum Origin of Cosmological Structure and Dynamical Reduction Theories

Summary

Access options

References

Save book to Kindle

Save book to Dropbox

Save book to Google Drive