Chromatic Quantum Contextuality

Chromatic quantum contextuality is a criterion of quantum nonclassicality based on (hyper)graph coloring constraints. If a quantum hypergraph requires more colors than the number of outcomes per maximal observable (context), it lacks a classical realization with <i>n</i>-uniform outcomes...

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Bibliographic Details
Main Author: Karl Svozil
Format: Article
Language:English
Published: MDPI AG 2025-04-01
Series:Entropy
Subjects:
Online Access:https://www.mdpi.com/1099-4300/27/4/387
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Summary:Chromatic quantum contextuality is a criterion of quantum nonclassicality based on (hyper)graph coloring constraints. If a quantum hypergraph requires more colors than the number of outcomes per maximal observable (context), it lacks a classical realization with <i>n</i>-uniform outcomes per context. Consequently, it cannot represent a “completable” noncontextual set of coexisting <i>n</i>-ary outcomes per maximal observable. This result serves as a chromatic analogue of the Kochen-Specker theorem. We present an explicit example of a four-colorable quantum logic in dimension three. Furthermore, chromatic contextuality suggests a novel restriction on classical truth values, thereby excluding two-valued measures that cannot be extended to <i>n</i>-ary colorings. Using this framework, we establish new bounds for the house, pentagon, and pentagram hypergraphs, refining previous constraints.
ISSN:1099-4300