Observables and Unobservables in Quantum Mechanics: How the No-Hidden-Variables Theorems Support the Bohmian Particle Ontology
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Relational Quantum Mechanics
Relational Quantum Mechanics Matteo Smerlak† September 17, 2006 †Ecole normale sup´erieure de Lyon, F-69364 Lyon, EU E-mail: [email protected] Abstract In this internship report, we present Carlo Rovelli’s relational interpretation of quantum mechanics, focusing on its historical and conceptual roots. A critical analysis of the Einstein-Podolsky-Rosen argument is then put forward, which suggests that the phenomenon of ‘quantum non-locality’ is an artifact of the orthodox interpretation, and not a physical effect. A speculative discussion of the potential import of the relational view for quantum-logic is finally proposed. Figure 0.1: Composition X, W. Kandinski (1939) 1 Acknowledgements Beyond its strictly scientific value, this Master 1 internship has been rich of encounters. Let me express hereupon my gratitude to the great people I have met. First, and foremost, I want to thank Carlo Rovelli1 for his warm welcome in Marseille, and for the unexpected trust he showed me during these six months. Thanks to his rare openness, I have had the opportunity to humbly but truly take part in active research and, what is more, to glimpse the vivid landscape of scientific creativity. One more thing: I have an immense respect for Carlo’s plainness, unaltered in spite of his renown achievements in physics. I am very grateful to Antony Valentini2, who invited me, together with Frank Hellmann, to the Perimeter Institute for Theoretical Physics, in Canada. We spent there an incredible week, meeting world-class physicists such as Lee Smolin, Jeffrey Bub or John Baez, and enthusiastic postdocs such as Etera Livine or Simone Speziale. -
Arxiv:2004.01992V2 [Quant-Ph] 31 Jan 2021 Ity [6–20]
Hidden Variable Model for Universal Quantum Computation with Magic States on Qubits Michael Zurel,1, 2, ∗ Cihan Okay,1, 2, ∗ and Robert Raussendorf1, 2 1Department of Physics and Astronomy, University of British Columbia, Vancouver, BC, Canada 2Stewart Blusson Quantum Matter Institute, University of British Columbia, Vancouver, BC, Canada (Dated: February 2, 2021) We show that every quantum computation can be described by a probabilistic update of a proba- bility distribution on a finite phase space. Negativity in a quasiprobability function is not required in states or operations. Our result is consistent with Gleason's Theorem and the Pusey-Barrett- Rudolph theorem. It is often pointed out that the fundamental objects In Theorem 2, we apply this to quantum computation in quantum mechanics are amplitudes, not probabilities with magic states, showing that universal quantum com- [1, 2]. This fact notwithstanding, here we construct a de- putation can be classically simulated by the probabilistic scription of universal quantum computation|and hence update of a probability distribution. of all quantum mechanics in finite-dimensional Hilbert This looks all very classical, and therein lies a puzzle. spaces|in terms of a probabilistic update of a probabil- In fact, our Theorem 2 is running up against a number ity distribution. In this formulation, quantum algorithms of no-go theorems: Theorem 2 in [23] and the Pusey- look structurally akin to classical diffusion problems. Barrett-Rudolph (PBR) theorem [24] say that probabil- While this seems implausible, there exists a well-known ity representations for quantum mechanics do not exist, special instance of it: quantum computation with magic and [9{13] show that negativity in certain Wigner func- states (QCM) [3] on a single qubit. -
An Energy and Determinist Approach of Quantum Mechanics Patrick Vaudon
An energy and determinist approach of quantum mechanics Patrick Vaudon To cite this version: Patrick Vaudon. An energy and determinist approach of quantum mechanics. 2018. hal-01714971v2 HAL Id: hal-01714971 https://hal.archives-ouvertes.fr/hal-01714971v2 Preprint submitted on 15 Mar 2018 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. An energy and determinist approach of quantum mechanics Patrick VAUDON Xlim lab – University of Limoges - France 0 Table of contents First part Classical approach of DIRAC equation and its solutions Introduction ............................................................................................................................................. 4 DIRAC equation ...................................................................................................................................... 9 DIRAC bi-spinors ................................................................................................................................. 16 Spin ½ of the electron .......................................................................................................................... -
Arxiv:1909.06771V2 [Quant-Ph] 19 Sep 2019
Quantum PBR Theorem as a Monty Hall Game Del Rajan ID and Matt Visser ID School of Mathematics and Statistics, Victoria University of Wellington, Wellington 6140, New Zealand. (Dated: LATEX-ed September 20, 2019) The quantum Pusey{Barrett{Rudolph (PBR) theorem addresses the question of whether the quantum state corresponds to a -ontic model (system's physical state) or to a -epistemic model (observer's knowledge about the system). We reformulate the PBR theorem as a Monty Hall game, and show that winning probabilities, for switching doors in the game, depend whether it is a -ontic or -epistemic game. For certain cases of the latter, switching doors provides no advantage. We also apply the concepts involved to quantum teleportation, in particular for improving reliability. Introduction: No-go theorems in quantum foundations Furthermore, concepts involved in the PBR proof have are vitally important for our understanding of quantum been used for a particular guessing game [43]. physics. Bell's theorem [1] exemplifies this by showing In this Letter, we reformulate the PBR theorem into that locally realistic models must contradict the experi- a Monty Hall game. This particular gamification of the mental predictions of quantum theory. theorem highlights that winning probabilities, for switch- There are various ways of viewing Bell's theorem ing doors in the game, depend on whether it is a -ontic through the framework of game theory [2]. These are or -epistemic game; we also show that in certain - commonly referred to as nonlocal games, and the best epistemic games switching doors provides no advantage. known example is the CHSH game; in this scenario the This may have consequences for an alternative experi- participants can win the game at a higher probability mental test of the PBR theorem. -
The World As Will and Quantum Mechanics
(https://thephilosophicalsalon.com) ! HOME (HTTPS://THEPHILOSOPHICALSALON.COM/) ABOUT (HTTPS://THEPHILOSOPHICALSALON.COM/ABOUT/) CONTACT US (HTTPS://THEPHILOSOPHICALSALON.COM/CONTACT/) DEBATES THE WORLD AS WILL AND JUL QUANTUM 22 2019 MECHANICS BY BENJAMIN WINTERHALTER (HTTPS://THEPHILOSOPHICALSALON.COM/AUTHOR/BENJAMININTERHALTER/) 4" SHARE 0# COMMENT 10♥ LOVE here is, unfortunately, no such thing as fate. If we accept that quantum mechanics— for all the strangeness associated with it—gives an accurate description of the T universe’s basic ontology, we should also accept that the will is real. The evidence for quantum mechanics is extremely strong, and physicists, including Alan Guth, David Kaiser, and Andrew Friedman (https://www.quantamagazine.org/physicists-are-closing-the-bell-test- loophole-20170207/), have closed some of the few remaining loopholes around the reality of quantum entanglement, a phenomenon wherein the state of a particle cannot be described independently of the state of at least one other. (Albert Einstein called entanglement “spooky action at a distance.”) But the existentially terrifying prospect of free will contains a shimmering surprise: In the conception of free will that’s compatible with quantum mechanics, exercises of the will—intentions or desires that lead to bodily actions—are fundamentally limited, finite, and constrained. In a word, entangled. According to the American philosopher John Searle’s 2004 book Freedom and Neurobiology, the fact of quantum indeterminacy—the ineradicable uncertainty in our knowledge of physical systems, first formulated by the German physicist Werner Heisenberg—does not guarantee that free will exists. Indeterminacy is a necessary but not sufficient condition for the belief that there is no such thing as fate. -
The Mathemathics of Secrets.Pdf
THE MATHEMATICS OF SECRETS THE MATHEMATICS OF SECRETS CRYPTOGRAPHY FROM CAESAR CIPHERS TO DIGITAL ENCRYPTION JOSHUA HOLDEN PRINCETON UNIVERSITY PRESS PRINCETON AND OXFORD Copyright c 2017 by Princeton University Press Published by Princeton University Press, 41 William Street, Princeton, New Jersey 08540 In the United Kingdom: Princeton University Press, 6 Oxford Street, Woodstock, Oxfordshire OX20 1TR press.princeton.edu Jacket image courtesy of Shutterstock; design by Lorraine Betz Doneker All Rights Reserved Library of Congress Cataloging-in-Publication Data Names: Holden, Joshua, 1970– author. Title: The mathematics of secrets : cryptography from Caesar ciphers to digital encryption / Joshua Holden. Description: Princeton : Princeton University Press, [2017] | Includes bibliographical references and index. Identifiers: LCCN 2016014840 | ISBN 9780691141756 (hardcover : alk. paper) Subjects: LCSH: Cryptography—Mathematics. | Ciphers. | Computer security. Classification: LCC Z103 .H664 2017 | DDC 005.8/2—dc23 LC record available at https://lccn.loc.gov/2016014840 British Library Cataloging-in-Publication Data is available This book has been composed in Linux Libertine Printed on acid-free paper. ∞ Printed in the United States of America 13579108642 To Lana and Richard for their love and support CONTENTS Preface xi Acknowledgments xiii Introduction to Ciphers and Substitution 1 1.1 Alice and Bob and Carl and Julius: Terminology and Caesar Cipher 1 1.2 The Key to the Matter: Generalizing the Caesar Cipher 4 1.3 Multiplicative Ciphers 6 -
The Case for Quantum State Realism
Western University Scholarship@Western Electronic Thesis and Dissertation Repository 4-23-2012 12:00 AM The Case for Quantum State Realism Morgan C. Tait The University of Western Ontario Supervisor Wayne Myrvold The University of Western Ontario Graduate Program in Philosophy A thesis submitted in partial fulfillment of the equirr ements for the degree in Doctor of Philosophy © Morgan C. Tait 2012 Follow this and additional works at: https://ir.lib.uwo.ca/etd Part of the Philosophy Commons Recommended Citation Tait, Morgan C., "The Case for Quantum State Realism" (2012). Electronic Thesis and Dissertation Repository. 499. https://ir.lib.uwo.ca/etd/499 This Dissertation/Thesis is brought to you for free and open access by Scholarship@Western. It has been accepted for inclusion in Electronic Thesis and Dissertation Repository by an authorized administrator of Scholarship@Western. For more information, please contact [email protected]. THE CASE FOR QUANTUM STATE REALISM Thesis format: Monograph by Morgan Tait Department of Philosophy A thesis submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy The School of Graduate and Postdoctoral Studies The University of Western Ontario London, Ontario, Canada © Morgan Tait 2012 THE UNIVERSITY OF WESTERN ONTARIO School of Graduate and Postdoctoral Studies CERTIFICATE OF EXAMINATION Supervisor Examiners ______________________________ ______________________________ Dr. Wayne Myrvold Dr. Dan Christensen Supervisory Committee ______________________________ Dr. Robert Spekkens ______________________________ Dr. Robert DiSalle ______________________________ Dr. Chris Smeenk The thesis by Morgan Christopher Tait entitled: The Case for Quantum State Realism is accepted in partial fulfillment of the requirements for the degree of « Doctor of Philosophy» ______________________ _______________________________ Date Chair of the Thesis Examination Board ii Abstract I argue for a realist interpretation of the quantum state. -
Reformulation of Quantum Mechanics and Strong Complementarity from Bayesian Inference Requirements
Reformulation of quantum mechanics and strong complementarity from Bayesian inference requirements William Heartspring Abstract: This paper provides an epistemic reformulation of quantum mechanics (QM) in terms of inference consistency requirements of objective Bayesianism, which include the principle of maximum entropy under physical constraints. Physical constraints themselves are understood in terms of consistency requirements. The by-product of this approach is that QM must additionally be understood as providing the theory of theories. Strong complementarity - that dierent observers may live in separate Hilbert spaces - follows as a consequence, which resolves the rewall paradox. Other clues pointing to this reformu- lation are analyzed. The reformulation, with the addition of novel transition probability arithmetic, resolves the measurement problem completely, thereby eliminating subjectivity of measurements from quantum mechanics. An illusion of collapse comes from Bayesian updates by observer's continuous outcome data. Dark matter and dark energy pop up directly as entropic tug-of-war in the reformulation. Contents 1 Introduction1 2 Epistemic nature of quantum mechanics2 2.1 Area law, quantum information and spacetime2 2.2 State vector from objective Bayesianism5 3 Consequences of the QM reformulation8 3.1 Basis, decoherence and causal diamond complementarity 12 4 Spacetime from entanglement 14 4.1 Locality: area equals mutual information 14 4.2 Story of Big Bang cosmology 14 5 Evidences toward the reformulation 14 5.1 Quantum redundancy 15 6 Transition probability arithmetic: resolving the measurement problem completely 16 7 Conclusion 17 1 Introduction Hamiltonian formalism and Schrödinger picture of quantum mechanics are assumed through- out the writing, with time t 2 R. Whenever the word entropy is mentioned without addi- tional qualication, it refers to von Neumann entropy. -
Antum Entanglement in Time
antum Entanglement in Time by Del Rajan A thesis submied to the Victoria University of Wellington in fullment of the requirements for the degree of Doctor of Philosophy Victoria University of Wellington 2020 Abstract is thesis is in the eld of quantum information science, which is an area that reconceptualizes quantum physics in terms of information. Central to this area is the quantum eect of entanglement in space. It is an interdependence among two or more spatially separated quantum systems that would be impossible to replicate by classical systems. Alternatively, an entanglement in space can also be viewed as a resource in quantum information in that it allows the ability to perform information tasks that would be impossible or very dicult to do with only classical information. Two such astonishing applications are quantum com- munications which can be harnessed for teleportation, and quantum computers which can drastically outperform the best classical supercomputers. In this thesis our focus is on the theoretical aspect of the eld, and we provide one of the rst expositions on an analogous quantum eect known as entanglement in time. It can be viewed as an interdependence of quantum systems across time, which is stronger than could ever exist between classical systems. We explore this temporal eect within the study of quantum information and its foundations as well as through relativistic quantum information. An original contribution of this thesis is the design of one of the rst quantum information applications of entanglement in time, namely a quantum blockchain. We describe how the entanglement in time provides the quantum advantage over a classical blockchain. -
An Argument for 4D Blockworld from a Geometric Interpretation of Non-Relativistic Quantum Mechanics Michael Silberstein1,3, Michael Cifone3 and W.M
An Argument for 4D Blockworld from a Geometric Interpretation of Non-relativistic Quantum Mechanics Michael Silberstein1,3, Michael Cifone3 and W.M. Stuckey2 Abstract We use a new distinctly “geometrical” interpretation of non-relativistic quantum mechanics (NRQM) to argue for the fundamentality of the 4D blockworld ontology. Our interpretation rests on two formal results: Kaiser, Bohr & Ulfbeck and Anandan showed independently that the Heisenberg commutation relations of NRQM follow from the relativity of simultaneity (RoS) per the Poincaré Lie algebra, and Bohr, Ulfbeck & Mottelson showed that the density matrix for a particular NRQM experimental outcome may be obtained from the spacetime symmetry group of the experimental configuration. Together these formal results imply that contrary to accepted wisdom, NRQM, the measurement problem and so-called quantum non-locality do not provide reasons to abandon the 4D blockworld implication of RoS. After discussing the full philosophical implications of these formal results, we motivate and derive the Born rule in the context of our ontology of spacetime relations via Anandan. Finally, we apply our explanatory and descriptive methodology to a particular experimental set-up (the so-called “quantum liar experiment”) and thereby show how the blockworld view is not only consistent with NRQM, not only an implication of our geometrical interpretation of NRQM, but it is necessary in a non-trivial way for explaining quantum interference and “non-locality” from the spacetime perspective. 1 Department of Philosophy, Elizabethtown College, Elizabethtown, PA 17022, [email protected] 2 Department of Physics, Elizabethtown College, Elizabethtown, PA 17022, [email protected] 3 Department of Philosophy, University of Maryland, College Park, MD 20742, [email protected] 2 1. -
Yet Again, Quantum Indeterminacy Is Not Worldly Indecision
Noname manuscript No. (will be inserted by the editor) Yet Again, Quantum Indeterminacy is not Worldly Indecision Alberto Corti January 18, 2021 Pre-print. Accepted in Synthese. The link to the published version will be added soon. Abstract It has been argued that non-relativistic quantum mechanics is the best hunting ground for genuine examples of metaphysical indeterminacy. Ap- proaches to metaphysical indeterminacy can be divided into two families: meta-level and object-level accounts. It has been shown (Darby, 2010; Skow, 2010) that the most popular version of the meta-level accounts, namely the metaphysical supervaluationism proposed by Barnes and Williams (2011), fails to deal with quantum indeterminacy. Such a fact has been taken by many as a challenge to adapt supervaluationism to quantum cases. In this paper, I will focus on the very last of these attempts, i.e. the situation semantics account proposed by Darby and Pickup (2019). After having shown where quantum indeterminacy arises and having surveyed the assumptions endorsed by the participants of the debate, I turn to Darby and Pickup's proposal. I argue that, despite the machinery introduced, their account still fails to account for quantum indeterminacy. After considering some possible counterarguments, I suggest in the conclusion that one can plausibly extend the argument to those meta-level approaches that treat quantum indeterminacy as worldly indeci- sion. Keywords Metaphysical Indeterminacy · Meta-Level Accounts · Quantum Mechanics · Metaphysics of Science · Situation Semantics Alberto Corti [email protected] Department of Philosophy, University of Geneva. Department of Pure and Applied Sciences, University of Urbino. 2 Alberto Corti 1 Introduction Metaphysical indeterminacy (henceforth `MI') is the idea that indeterminacy is a feature of the world itself, rather than a feature imputable to the words we use (Fine, 1975) or to our knowledge (Williamson, 1994). -
Like Other Physical Theories, Quantum Mechanics Deals with Repeatable
Chapter 16 Free Will 16.1 The Problem The nature and existence of free will are traditional philosophical topics. One can easily see why by noting that the notions of free will and moral responsibility are related. The nature of the connection is a matter of debate; however, one can minimally say that paradigmatic cases of moral responsibility occur only when the agent acted of his own free will. Many have viewed free will as threatened both by theology and science.1 Leaving theology aside, the main threat coming from science has been represented by determinism, which we must now briefly consider. Determinism is the view that if at a time two isolated systems are described by the same state equation, then they have always been and will always be described the same equations and that two systems in the very same state always display the same properties. In effect, determinism is equivalent to the combination of evolutionary and value determinism. Classical mechanics is often taken to embody determinism, but to what 1 The theological problem is this. The traditional orthodox God knows the future. If God knows today that tomorrow at 3:23 pm I shall mow the lawn, then it looks as if mowing the lawn is not really up to me, since if I were to abstain from it I would turn God’s knowledge into mere belief, something that both philosophy and piety seem to prevent. Note, by the way, that the problem, albeit in a slightly different version, remains even if we dispose of God.