A no-go theorem for the persistent reality of Wigner's friend's perception

• URL: http://arxiv.org/abs/2009.09499v2
• Date: Mon, 17 May 2021 14:48:15 GMT
• Title: A no-go theorem for the persistent reality of Wigner's friend's perception
• Authors: Philippe Allard Gu\'erin, Veronika Baumann, Flavio Del Santo, \v{C}aslav Brukner
• Abstract summary: We formulate a no-go theorem for the persistent reality of Wigner's friend's perception. In a Wigner's friend scenario, there is no joint probability distribution for the friend's perceived measurement outcomes at two different times. We briefly discuss which of the theorem's assumptions are more likely to be dropped within various popular interpretations of quantum mechanics.
• Score: 0.0
• License: http://arxiv.org/licenses/nonexclusive-distrib/1.0/
• Abstract: The notorious Wigner's friend thought experiment (and modifications thereof) has in recent years received renewed interest especially due to new arguments that force us to question some of the fundamental assumptions of quantum theory. In this paper, we formulate a no-go theorem for the persistent reality of Wigner's friend's perception, which allows us to conclude that the perceptions that the friend has of her own measurement outcomes at different times cannot "share the same reality", if seemingly natural quantum mechanical assumptions are met. More formally, this means that, in a Wigner's friend scenario, there is no joint probability distribution for the friend's perceived measurement outcomes at two different times, that depends linearly on the initial state of the measured system and whose marginals reproduce the predictions of unitary quantum theory. This theorem entails that one must either (1) propose a nonlinear modification of the Born rule for two-time predictions, (2) sometimes prohibit the use of present information to predict the future -- thereby reducing the predictive power of quantum theory -- or (3) deny that unitary quantum mechanics makes valid single-time predictions for all observers. We briefly discuss which of the theorem's assumptions are more likely to be dropped within various popular interpretations of quantum mechanics.

Related papers

• Testing trajectory-based determinism via time probability distributions [44.99833362998488]
  Bohmian mechanics (BM) has inherited more predictive power than quantum mechanics (QM) We introduce a prescription for constructing a flight-time probability distribution within generic trajectory-equipped theories. We derive probability distributions that are unreachable by QM.
  arXiv  Detail & Related papers  (2024-04-15T11:36:38Z)
• Epistemic Boundaries and Quantum Uncertainty: What Local Observers Can (Not) Predict [0.0]
  We argue that post-quantum theories can offer a predictive advantage while conforming to the Born rule on average. We uncover a fascinating possibility: When the assumption of reliable intersubjectivity between different observers is violated, subjective predictive advantage can, in principle, exist. The findings reconcile us to quantum uncertainty as an aspect of limits on Nature's predictability.
  arXiv  Detail & Related papers  (2023-10-13T14:09:18Z)
• Logic meets Wigner's Friend (and their Friends) [49.1574468325115]
  We take a fresh look at Wigner's Friend thought-experiment and some of its more recent variants and extensions. We discuss various solutions proposed in the literature, focusing on a few questions.
  arXiv  Detail & Related papers  (2023-07-04T13:31:56Z)
• Connecting classical finite exchangeability to quantum theory [69.62715388742298]
  Exchangeability is a fundamental concept in probability theory and statistics. We show how a de Finetti-like representation theorem for finitely exchangeable sequences requires a mathematical representation which is formally equivalent to quantum theory.
  arXiv  Detail & Related papers  (2023-06-06T17:15:19Z)
• Theorems motivated by foundations of quantum mechanics and some of their applications [0.0]
  This paper provides theorems aimed at shedding light on issues in the foundations of quantum mechanics. theorems can be used to propose new interpretations to the theory, or to better understand, evaluate and improve current interpretations.
  arXiv  Detail & Related papers  (2022-02-02T21:55:57Z)
• Events in quantum mechanics are maximally non-absolute [0.9176056742068814]
  We prove that quantum correlations can be maximally non-absolute according to both quantifiers. We show that chained Bell inequalities (and relaxations thereof) are also valid constraints for Wigner's experiment.
  arXiv  Detail & Related papers  (2021-12-19T21:15:16Z)
• Quantum realism: axiomatization and quantification [77.34726150561087]
  We build an axiomatization for quantum realism -- a notion of realism compatible with quantum theory. We explicitly construct some classes of entropic quantifiers that are shown to satisfy almost all of the proposed axioms.
  arXiv  Detail & Related papers  (2021-10-10T18:08:42Z)
• Quantum indistinguishability through exchangeable desirable gambles [69.62715388742298]
  Two particles are identical if all their intrinsic properties, such as spin and charge, are the same. Quantum mechanics is seen as a normative and algorithmic theory guiding an agent to assess her subjective beliefs represented as (coherent) sets of gambles. We show how sets of exchangeable observables (gambles) may be updated after a measurement and discuss the issue of defining entanglement for indistinguishable particle systems.
  arXiv  Detail & Related papers  (2021-05-10T13:11:59Z)
• Observers of quantum systems cannot agree to disagree [55.41644538483948]
  We ask whether agreement between observers can serve as a physical principle that must hold for any theory of the world. We construct examples of (postquantum) no-signaling boxes where observers can agree to disagree.
  arXiv  Detail & Related papers  (2021-02-17T19:00:04Z)
• A strong no-go theorem on the Wigner's friend paradox [0.0]
  We prove that if quantum evolution is controllable on the scale of an observer, then one of 'No-Superdeterminism', 'Locality' or 'Absoluteness of Observed Events' must be false. We show that although the violation of Bell-type inequalities in such scenarios is not in general sufficient to demonstrate the contradiction between those three assumptions, new inequalities can be derived in a theory-independent manner.
  arXiv  Detail & Related papers  (2019-07-12T08:09:44Z)
• Symmetric Informationally Complete Measurements Identify the Irreducible Difference between Classical and Quantum Systems [0.0]
  We describe a general procedure for associating a minimal informationally-complete quantum measurement (or MIC) with a set of linearly independent post-measurement quantum states. We prove that the representation of the Born Rule obtained from a symmetric informationally-complete measurement (or SIC) minimizes this distinction in at least two senses.
  arXiv  Detail & Related papers  (2018-05-22T16:27:27Z)

This list is automatically generated from the titles and abstracts of the papers in this site.

This site does not guarantee the quality of this site (including all information) and is not responsible for any consequences.