Non-locality, contextuality and valuation algebras: a general theory of disagreement Samson Abramsky1, Giovanni Carù1 1Department of Computer Science, University of Subject Areas: Oxford, Wolfson Building, Parks Road, Oxford OX1 Quantum information, quantum 3QD, U.K. foundations, generic inference Keywords: We establish a strong link between two apparently Contextuality, generic inference, unrelated topics: the study of conflicting information valuation algebras, algorithms in the formal framework of valuation algebras, and the phenomena of non-locality and contextuality. In particular, we show that these peculiar features of Email addresses: quantum theory are mathematically equivalent to a Samson Abramsky general notion of disagreement between information
[email protected] sources. This result vastly generalises previously observed connections between contextuality, relational databases, constraint satisfaction problems, and logical paradoxes, and gives further proof that contextual behaviour is not a phenomenon limited to quantum physics, but pervades various domains of mathematics and computer science. The connection allows to translate theorems, methods and algorithms from one field to the other, and paves the way for the application of generic inference algorithms to study contextuality. 1. Introduction Non-locality and contextuality are characteristic features of quantum theory which have been recently proven to play a crucial role as fundamental resources for quantum information and computation [1,2]. In 2011, Abramsky and Brandenburger introduced an abstract mathematical framework based on sheaf theory to describe these phenomena in a unified treatment, thereby providing a common general theory for the study of non-locality and contextuality, which had been carried out in a rather arXiv:1911.03521v1 [quant-ph] 8 Nov 2019 concrete, example-driven fashion until then [3].