• Are There Observational Differences Between Bohmian Mechanics and Other Interpretations?
    In Angelo Bassi, Sheldon Goldstein, Roderich Tumulka & Nino Zanghì (eds.), Physics and the Nature of Reality: Essays in Memory of Detlef Dürr, Springer. pp. 141-150. 2024.
    While there is a consensus that leading interpretations of quantum mechanics cannot be distinguished with today’s technology, it is unclear if a gedanken experiment which relies on unlimited technological power cannot do so. Another gedanken approach is considering sentient beings which have brains different from ours. Such gedanken situations will be analyzed with emphasis on a possible difference between Bohmian mechanics and the many-worlds interpretation.
  • The Two-State Vector Formalism of Quantum Mechanics: an Updated Review
    with Y. Aharonov
    In J. G. Muga, R. Sala Mayato & I. L. Egusquiza (eds.), \em Time in Quantum Mechanics, Springer. pp. 397-447. 2008.
  •  295
    The many worlds interpretation of quantum mechanics (MWI) states that the world we live in is just one among many parallel worlds. It is widely believed that because of this commitment to parallel worlds, the MWI violates common sense. Some go so far as to reject the MWI on this basis. This is despite its myriad of advantages to physics (e.g. consistency with relativity theory, mathematical simplicity, realism, determinism, etc.). Here, we make the case that common sense in fact favors the MWI. …Read more
  • Time Symmetry and the Many-Worlds Interpretation
    In Simon Saunders, Jonathan Barrett, Adrian Kent & David Wallace (eds.), Many Worlds?: Everett, Quantum Theory, & Reality, Oxford University Press. 2010.
  •  18
    There is No New Problem for Quantum Mechanics
    Foundations of Physics 50 (11): 1728-1734. 2020.
    A recent claim by Meehan that quantum mechanics has a new “control problem” that puts limits on our ability to prepare quantum states and revises our understanding of the no-cloning theorem is examined. We identify flaws in Meehan’s analysis and argue that such a problem does not exist.
  •  93
    Ontology of the wave function and the many-worlds interpretation (edited book)
    Cambridge University Press, UK. 2019.
    It is argued that the many-worlds interpretation is by far the best interpretation of quantum mechanics. The key points of this view are viewing the wave functions of worlds in three dimensions and understanding probability through self-locating uncertainty.
  •  128
    In defence of the self-location uncertainty account of probability in the many-worlds interpretation
    Studies in History and Philosophy of Science Part B: Studies in History and Philosophy of Modern Physics 66 (C): 14-23. 2019.
    We defend the many-worlds interpretation of quantum mechanics against the objection that it cannot explain why measurement outcomes are predicted by the Born probability rule. We understand quantum probabilities in terms of an observer's self-location probabilities. We formulate a probability postulate for the MWI: the probability of self-location in a world with a given set of outcomes is the absolute square of that world's amplitude. We provide a proof of this postulate, which assumes the quan…Read more
  •  21
    Comment on “Non-representative Quantum Mechanical Weak Values”
    with Lev Vaidman and Alon Ben-Israel
    Foundations of Physics 47 (4): 467-470. 2017.
    Svensson argued that the concept of the weak value of an observable of a pre- and post-selected quantum system cannot be applied when the expectation value of the observable in the initial state vanishes. Svensson’s argument is analyzed and shown to be inconsistent using several examples.
  •  38
    The Meaning of the Interaction-Free Measurements
    Foundations of Physics 33 (3): 491-510. 2003.
    Interaction-free measurements introduced by Elitzur and Vaidman [Found. Phys. 23, 987 (1993)] allow finding infinitely fragile objects without destroying them. Many experiments have been successfully performed showing that indeed, the original scheme and its modifications lead to reduction of the disturbance of the observed systems. However, there is a controversy about the validity of the term “interaction-free” for these experiments. Broad variety of such experiments are reviewed and the meani…Read more
  •  142
    This is a philosophical paper in favor of the many-worlds interpretation of quantum theory. The necessity of introducing many worlds is explained by analyzing a neutron interference experiment. The concept of the “measure of existence of a world” is introduced and some difficulties with the issue of probability in the framework of the MWI are resolved
  •  20
    It is argued that the criticism of Byrne and Hall of the argument of Chalmers in favor of the Everett-style interpretation is incorrect.
  •  40
    Weak-measurement elements of reality
    Foundations of Physics 26 (7): 895-906. 1996.
    A brief review of the attempts to define “elements of reality” in the framework of quantum theory is presented. It is noted that most definitions of elements of reality have in common the feature to be a definite outcome of some measurement. Elements of reality are extended to pre- and post- selected systems and to measurements which fulfill certain criteria of weakness of the coupling. Some features of the newly introduced concepts are discussed
  •  29
    It is argued that thirder resolution of the Lewis - Elga controversy about Sleeping Beauty is more clear when the coin toss is replaced by a quantum measurement and the analysis is performed in the framework of the Many-Worlds Interpretation.
  •  239
    Many-worlds interpretation of quantum mechanics
    Stanford Encyclopedia of Philosophy. 2008.
    The Many-Worlds Interpretation (MWI) is an approach to quantum mechanics according to which, in addition to the world we are aware of directly, there are many other similar worlds which exist in parallel at the same space and time. The existence of the other worlds makes it possible to remove randomness and action at a distance from quantum theory and thus from all physics
  •  366
    The measure of existence of a quantum world and the Sleeping Beauty Problem
    with Berry Groisman and Na'ama Hallakoun
    Analysis 73 (4): 695-706. 2013.
    Next SectionAn attempt to resolve the controversy regarding the solution of the Sleeping Beauty Problem in the framework of the Many-Worlds Interpretation led to a new controversy regarding the Quantum Sleeping Beauty Problem. We apply the concept of a measure of existence of a world and reach the solution known as ‘thirder’ solution which differs from Peter Lewis’s ‘halfer’ assertion. We argue that this method provides a simple and powerful tool for analysing rational decision theory problems
  •  47
    Several situations, in which an empty wave causes an observable effect, are reviewed. They include an experiment showing ‘‘surrealistic trajectories’’ proposed by Englert et al. and protective measurement of the density of the quantum state. Conditions for observable effects due to empty waves are derived. The possibility (in spite of the existence of these examples) of minimalistic interpretation of Bohmian quantum mechanics in which only Bohmian positions supervene on our experience is discuss…Read more
  •  126
    On the Paradoxical Aspects of New Quantum Experiments
    PSA: Proceedings of the Biennial Meeting of the Philosophy of Science Association 1994. 1994.
    Two recently proposed quantum experiments are analyzed. The first allows to find an object without "touching" it. The second allows to teleport quantum states, transmitting a very small amount of information. It is shown that in the standard approach these experiments are in conflict with the intuitive notions of causality and locality. It is argued that the situation is less paradoxical in the framework of the many-worlds interpretation of quantum theory
  •  36
    It is argued that the lesson we should learn from Bell's inequalities is not that quantum mechanics requires some kind of action at a distance, but that it leads us to believe in parallel worlds.
  •  141
    Time-Symmetrized Counterfactuals in Quantum Theory
    Foundations of Physics 29 (5): 755-765. 1999.
    Counterfactuals in quantum theory are briefly reviewed and it is argued that they are very different from counterfactuals considered in the general philosophical literature. The issue of time symmetry of quantum counterfactuals is considered and a novel time-symmetric definition of quantum counterfactuals is proposed. This definition is applied for analyzing several controversies related to quantum counterfactuals
  •  31
    It is argued that standard quantum theory without collapse provides a satisfactory explanation of everything we experience in this and in numerous parallel worlds. The only fundamental ontology is the universal wave function evolving in a deterministic way without action at a distance.
  •  75
    Time Symmetry and the Many-Worlds Interpretation
    In Simon Saunders, Jonathan Barrett, Adrian Kent & David Wallace (eds.), Many Worlds?: Everett, Quantum Theory & Reality, Oxford University Press. 2009.
    An attempt to solve the collapse problem in the framework of a time-symmetric quantum formalism is reviewed. Although the proposal does not look very attractive, its concept - a world defined by two quantum states, one evolving forwards and one evolving backwards in time - is found to be useful in modifying the many-worlds picture of Everett’s theory
  •  74
    Probability in the Many-Worlds Interpretation of Quantum Mechanics
    In Yemima Ben-Menahem & Meir Hemmo (eds.), Probability in Physics, Springer. pp. 299--311. 2011.
    It is argued that, although in the Many-Worlds Interpretation of quantum mechanics there is no ``probability'' for an outcome of a quantum experiment in the usual sense, we can understand why we have an illusion of probability. The explanation involves: a). A ``sleeping pill'' gedanken experiment which makes correspondence between an illegitimate question: ``What is the probability of an outcome of a quantum measurement?'' with a legitimate question: ``What is the probability that ``I'' am in th…Read more
  •  70
    There is a trend to consider counterfactuals as invariably time-asymmetric. Recently, this trend manifested itself in the controversy about validity of counterfactual application of a time-symmetric quantum probability rule. Kastner (2003) analyzed this controversy and concluded that there are time-symmetric quantum counterfactuals which are consistent, but they turn out to be trivial. I correct Kastner's misquotation of my defense of time-symmetric quantum counterfactuals and explain their non-…Read more
  •  83
    The meaning of protective measurements
    with Yakir Aharonov and Jeeva Anandan
    Foundations of Physics 26 (1): 117-126. 1996.
    Protective measurement, which we have introduced recently, allows one to observe properties of the state of a single quantum system and even the Schrödinger wave itself. These measurements require a protection, sometimes due to an additional procedure and sometimes due to the potential of the system itself The analysis of the protective measurements is presented and it is argued, contrary to recent claims, that they observe the quantum state and not the protective potential. Some other misunders…Read more
  •  45
    This paper is an answer to the preceding paper by Kastner, in which she continued the criticism of the counterfactual usage of the Aharonov-Bergman-Lebowitz rule in the framework of the time-symmetrized quantum theory, in particular, by analyzing the three-box “paradox.” It is argued that the criticism is not sound. Paradoxical features of the three-box example are discussed. It is explained that the elements of reality in the framework of time-symmetrized quantum theory are counterfactual state…Read more
  •  81
    It is argued that Lewis's approach to Elga's Sleeping Beaty problem is untenable and, therefore, the universality of the betting approach to probability has not been breached.
  •  36
    A quantum time machine
    Foundations of Physics 21 (8): 947-958. 1991.
    A novel description of quantum systems is employed for constructing a “time machine” capable of shifting in time the wave function of a quantum system. This device uses gravitational time dilations and a peculiar quantum interference effect due to preselection and postselection. In most trials this time machine fails to operate but when it does succeed it accomplishes tasks which no other machine can
  •  71
    Variations on the Theme of the Greenberger-Horne-Zeilinger Proof
    Foundations of Physics 29 (4): 615-630. 1999.
    Three arguments based on the Greenberger-Horne-Zeilinger (GHZ) proof of the nonexistence of local hidden variables are presented. The first is a description of a simple game which a team that uses the GHZ method will always win. The second uses counterfactuals in an attempt to show that quantum theory is nonlocal in a stronger sense than is implied by the nonexistence of local hidden variables and the third describes peculiar features of time-symmetrized counterfactuals in quantum theory
  •  70
    Historically, appearance of the quantum theory led to a prevailing view that Nature is indeterministic. The arguments for the indeterminism and proposals for indeterministic and deterministic approaches are reviewed. These include collapse theories, Bohmian Mechanics and the many-worlds interpretation. It is argued that ontic interpretations of the quantum wave function provide simpler and clearer physical explanation and that the many-worlds interpretation is the most attractive since it provid…Read more