No-hypersignaling principle

Abstract

A paramount topic in quantum foundations, rooted in the study of the EPR paradox and Bell inequalities, is that of characterizing quantum theory in terms of the space-like correlations it allows. Here we show that to focus only on space-like correlations is not enough: we explicitly construct a toy model theory that, while not contradicting classical and quantum theories at the level of space-like correlations, still displays an anomalous behavior in its time-like correlations. We call this anomaly, quantified in terms of a specific communication game, the "hypersignaling" phenomena. We hence conclude that the "principle of quantumness," if it exists, cannot be found in space-like correlations alone: nontrivial constraints need to be imposed also on time-like correlations, in order to exclude hypersignaling theories.

6 + 7 pages, 4 figures, 1 table, published version, PRL Editors' Suggestion, typos fixed

References in corpus (5)

• The Feynman problem and Fermionic entanglement: Fermionic theory versus qubit theory
• Non-classicality of temporal correlations
• Dimension of physical systems, information processing, and thermodynamics
• Information Content of Systems as a Physical Principle
• Hyperdense coding and superadditivity of classical capacities in hypersphere theories

Cited by in corpus (26)

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• Nonlocality Without Entanglement: Quantum Theory and Beyond
• Classical theories with entanglement
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• Classical Cost of Transmitting a Qubit
• The Communication Value of a Quantum Channel
• On entanglement assistance to a noiseless classical channel
• Communication tasks in operational theories
• Advantage of Quantum Theory Over Non-classical Models of Communication
• Information and disturbance in operational probabilistic theories
• Classical simulations of communication channels
• Certifying the Classical Simulation Cost of a Quantum Channel
• Classical analogue of quantum superdense coding and communication advantage of a single quantum system
• Many-box locality
• Bell measurement rules out supraquantum correlations
• Information capacity of quantum communication under natural physical assumptions
• Some no-go results in Quantum Thermodynamics
• Timelike correlations and quantum tensor product structure
• Scalable & Noise-Robust Communication Advantage of Multipartite Quantum Entanglement
• The signaling dimension of physical systems
• Quantum Advantage: A Single Qubit's Experimental Edge in Classical Data Storage
• Certifying measurement incompatibility in prepare-and-measure and Bell scenarios
• Bipartite polygon models: entanglement classes and their nonlocal behaviour
• Gottesman-Knill Limit on One-way Communication Complexity: Tracing the Quantum Advantage down to Magic Resources
• Randomness-free Detection of Non-projective Measurements: Qubits & beyond
• The signaling dimension in generalized probabilistic theories