Decoherence, Branching, and the Born Rule in a Mixed-State Everettian Multiverse: Conclusion

Written by multiversetheory | Published 2024/02/20
Tech Story Tags: quantum-mechanics | decoherence | multiverse-theory | everettian-multiverses | mixed-state-multiverse | density-matrix-realism | wave-function-realism | everettian-quantum-mechanics

TLDRIn conclusion, Everettian quantum mechanics presents a choice between wave function and density matrix realism, with implications for understanding decoherence, branching, and the Born rule. Explore the theoretical crossroads and empirical underdetermination in quantum interpretation, leaving open avenues for future research. TLDR: Everettian quantum mechanics offers two versions - wave function and density matrix realism - with implications for key concepts like decoherence and the Born rule. The choice between these theories isn't based on empirical grounds but involves other theoretical considerations, highlighting the empirical underdetermination in quantum interpretation. Future research will delve deeper into these implications and potential resolutions. via the TL;DR App

Authors:

(1) Eugene Y. S. Chua, Division of the Humanities and Social Sciences, California Institute of Technology;

(2) Eddy Keming Chen, ‡Department of Philosophy, University of California.

Table of Links

Abstract & Introduction

Decoherence and Branching

The Born Rule

Discussion

Conclusion and References

5 Conclusion

We suggest that the Evere‹ian understanding of decoherence and branching, as well as the justifications for the Born rule, apply to both WFRE and DMRE. Hence, the theoretical benefits of DMR are available on EQM. Another consequence is that Everettians face a choice between two types of theories, one allowing only pure states for the multiverse and the other allowing mixed states also. The choice will not be based on different understandings of the branching structure or the Born rule, as the Everettian justifications equally apply in both theories, but must involve some other theoretical considerations. In any case, the availability of different versions of EQM is an interesting example of empirical underdetermination. Its implications and possible resolutions are questions we leave for future work.

Acknowledgements

For helpful feedback, we thank Jefferey Barrett, Charles Sebens, Kelvin McQueen, Katie Robertson, Simon Saunders, Tony Short, Karim Thebault, David Wallace, and the ´ participants at the 2023 Workshop on Relational Clocks, Decoherence, and the Arrow of Time at the University of Bristol, and the 2022 California Quantum Interpretation Network Conference at Chapman University.

References

Albert, David. “Elementaryantum Metaphysics”. In: Bohmian Mechanics and Quantum theory: An Appraisal. Ed. by J. T. Cushing, Arthur Fine, and Sheldon Goldstein. Kluwer Academic Publishers, 1996, pp. 277–284.

— Time and chance. Cambridge: Harvard University Press, 2000.

Allori, Valia et al. “Predictions and primitive ontology in quantum foundations: a study of examples”. In: The British Journal for the Philosophy of Science 65.2 (2013), pp. 323–352.

Baker, David. “Measurement outcomes and probability in Everettian quantum mechanics”. In: Studies in History and Philosophy of Science Part B: Studies in History and Philosophy of Modern Physics 38.1 (2007), pp. 153–169.

Barrett, Jeffrey. “Everettian Quantum Mechanics”. In: The Stanford Encyclopedia of Philosophy. Ed. by Edward N. Zalta and Uri Nodelman. Summer 2023. Metaphysics Research Lab, Stanford University, 2023.

Chen, Eddy Keming. “From time asymmetry to quantum entanglement: The Humean unification”. In: Nousˆ 56 (2022), pp. 227–255.

— “Fundamental Nomic Vagueness”. In: The Philosophical Review 131(1) (2022).

— “Quantum Mechanics in a Time-Asymmetric Universe: On the Nature of the Initial Quantum State”. In: The British Journal for the Philosophy of Science 72.4 (2021), pp. 1155–1183.

— “Realism about the wave function”. In: Philosophy Compass 14.7 (2019).

— “Strong Determinism”. In: Philosophers’ Imprint forthcoming (2022).

— “Time’s Arrow in a Quantum Universe: On the Status of Statistical Mechanical Probabilities”. In: Statistical Mechanics and Scientific Explanation: Determinism, Indeterminism and Laws of Nature. Ed. by Valid Allori. Singapore: World Scientific, 2020.

Deutsch, David. “Quantum Theory of probability and decisions”. In: Proceedings of the Royal Society of London. Series A: Mathematical, Physical and Engineering Sciences 455.1988 (1999), pp. 3129–3137.

Durr, Detlef et al. “On the role of density matrices in Bohmian m ¨ echanics”. In: Foundations of Physics 35.3 (2005), pp. 449–467.

Kent, Adrian. “307One World Versus Many: ‘e Inadequacy of Everettian Accounts of Evolution, Probability, and Scientific Confirmation”. In: Many Worlds?: Everett, Quantum Theory, and Reality. Oxford University Press, June 2010.

Maroney, Owen. “The Density Matrix in the de Broglie–Bohm Approach”. In: Foundations of Physics 35.3 (2005), pp. 493–510.

McQueen, Kelvin J. and Lev Vaidman. “In defence of the self-location uncertainty account of probability in the many-worlds interpretation”. In: Studies in History and Philosophy of Science Part B: Studies in History and Philosophy of Modern Physics 66 (2018), pp. 14–23.

Ney, Alyssa. The world in the wave function: a metaphysics for quantum physics. Oxford University Press, 2021.

Nielsen, Michael A and Isaac L Chuang. Quantum computation and quantum information. Cambridge university press, 2010.

Robertson, Katie. “In search of the holy grail: How to reduce the second law of thermodynamics”. In: The British Journal for the Philosophy of Science 73.4 (2022), pp. 987– 1020.

Saunders, Simon. “Branch-counting in the Everett interpretation of quantum mechanics”. In: Proceedings of the Royal Society A 477.2255 (2021), p. 20210600.

Schlosshauer, Maximilian A.Decoherence: and the quantum-to-classical transition. Springer Science & Business Media, 2007.

Sebens, Charles T. and Sean M. Carroll. “Self-Locating Uncertainty and the Origin of Probability in Everettian Quantum Mechanics”. In: British Journal for the Philosophy of Science 1 (2018), axw004.

Tappenden, Paul. “Evidence and Uncertainty in Everett?s Multiverse”. In: British Journal for the Philosophy of Science 62.1 (2011), pp. 99–123.

Vaidman, Lev. “Derivations of the Born Rule”. In: ‹antum, Probability, Logic: The Work and Influence of Itamar Pitowsky. Ed. by Meir Hemmo and Orly Shenker. Cham: Springer International Publishing, 2020, pp. 567–584.

— “Many-Worlds Interpretation of Quantum Mechanics”. In: The Stanford Encyclopedia of Philosophy. Ed. by Edward N. Zalta. Fall 2021. Metaphysics Research Lab, Stanford University, 2021. — “On schizophrenic experiences of the neutron or why we should believe in the many-worlds interpretation of quantum theory”. In: International Studies in the Philosophy of Science 12.3 (1998), pp. 245–261.

Wallace, David. Œe Emergent Multiverse: Quantum Theory According to the Everett Interpretation. Oxford University Press, 2012. — “The sky is blue, and other reasons quantum mechanics is not underdetermined by evidence”. In: arXiv preprint: 2205.00568 (2022).

This paper is available on arxiv under CC 4.0 license.


Written by multiversetheory | Delving into the ethereal fabric that connects the multiverse, with an adept exploration of the aetheric realms.
Published by HackerNoon on 2024/02/20