Events in quantum mechanics are maximally non-absolute

Abstract

The notorious quantum measurement problem brings out the difficulty to reconcile two quantum postulates: the unitary evolution of closed quantum systems and the wave-function collapse after a measurement. This problematics is particularly highlighted in the Wigner's friend thought experiment, where the mismatch between unitary evolution and measurement collapse leads to conflicting quantum descriptions for different observers. A recent no-go theorem has established that the (quantum) statistics arising from an extended Wigner's friend scenario is incompatible when one try to hold together three innocuous assumptions, namely no-superdeterminism, parameter independence and absoluteness of observed events. Building on this extended scenario, we introduce two novel measures of non-absoluteness of events. The first is based on the EPR2 decomposition, and the second involves the relaxation of the absoluteness hypothesis assumed in the aforementioned no-go theorem. To 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.

References in corpus (31)

• Bell nonlocality
• Decoherence, the measurement problem, and interpretations of quantum mechanics
• Relational Quantum Mechanics
• Dynamical Reduction Models
• Quantum probabilities as Bayesian probabilities
• How Quantum Mechanics can consistently describe the use of itself
• Quantum theory cannot consistently describe the use of itself
• Local deterministic model of singlet state correlations based on relaxing measurement independence
• A strong no-go theorem on the Wigner's friend paradox
• Rethinking Superdeterminism
• Tsirelson bounds for generalized Clauser-Horne-Shimony-Holt inequalities
• A no-go theorem for observer-independent facts
• A unifying framework for relaxations of the causal assumptions in Bell's theorem
• Experimental test of local observer-independence
• On nonlocality as a resource theory and nonlocality measures
• The Free-Will Postulate in Quantum Mechanics
• Self-testing protocols based on the chained Bell inequalities
• A no-go theorem for the persistent reality of Wigner's friend's perception
• Quantifying Bell: the Resource Theory of Nonclassicality of Common-Cause Boxes
• Quantum Theory and the Limits of Objectivity
• Quantifying Bell non-locality with the trace distance
• Toy Models for Retrocausality
• Generalized probability rules from a timeless formulation of Wigner's friend scenarios
• Physics and Metaphysics of Wigner's Friends: Even performed pre-measurements have no results
• The view from a Wigner bubble
• Complementary contributions of indeterminism and signalling to quantum correlations
• Inadequacy of Modal Logic in Quantum Settings
• Bell scenarios with communication
• Measurement-dependence cost for Bell nonlocality: causal vs retrocausal models
• The non-locality of n noisy Popescu-Rohrlich boxes
• On the quantum measurement problem