On Graph Approaches To Contextuality And Their Role In Quantum Theory

This book explores two of the most striking features of quantum theory – contextuality and nonlocality – using a formulation based on graph theory. Quantum theory provides a set of rules to predict probabilities of different outcomes in different experimental settings, and both contextuality and nonlocality play a fundamental role in interpreting the outcomes. In this work, the authors highlight how the graph approach can lead to a better understanding of this theory and its applications. After presenting basic definitions and explaining the non-contextuality hypothesis, the book describes contextuality scenarios using compatibility hypergraphs. It then introduces the exclusivity graph approach, which relates a number of important graph-theoretical concepts to contextuality. It also presents open problems such as the so-called Exclusivity Principle, as well as a selection of important topics, like sheaf-theoretical approach, hypergraph approach, and alternative proofs of contextuality.

This book presents the current views of leading physicists on the bizarre property of quantum theory: nonlocality. Einstein viewed this theory as “spooky action at a distance” which, together with randomness, resulted in him being unable to accept quantum theory. The contributions in the book describe, in detail, the bizarre aspects of nonlocality, such as Einstein–Podolsky–Rosen steering and quantum teleportation—a phenomenon which cannot be explained in the framework of classical physics, due its foundations in quantum entanglement. The contributions describe the role of nonlocality in the rapidly developing field of quantum information. Nonlocal quantum effects in various systems, from solid-state quantum devices to organic molecules in proteins, are discussed. The most surprising papers in this book challenge the concept of the nonlocality of Nature, and look for possible modifications, extensions, and new formulations—from retrocausality to novel types of multiple-world theories. These attempts have not yet been fully successful, but they provide hope for modifying quantum theory according to Einstein’s vision.

This book provides an interdisciplinary perspective on one of the most fascinating and important open questions in science: What is quantum mechanics talking about? Quantum theory is perhaps our best confirmed physical theory. However, despite its great empirical effectiveness and the subsequent technological developments that it gave rise to in the 20th century, from the interpretation of the periodic table of elements to CD players, holograms and quantum state teleportation, it stands even today without a universally accepted interpretation. The novelty of the book comes from the multiple viewpoints and subjects investigated by a group of researchers from Europe and North and South America.

This volume provides a summary of the lectures presented at the International School of Physics "Enrico Fermi" on the Foundations of Quantum Theory, organized by the Italian Physical Society in Varenna, Italy from 8-13 July 2016, in collaboration with the Wilhelm und Else Heraeus-Stiftung. It was the first "Enrico Fermi" Summer School on this topic since 1977. Its main goal was to provide an overview of the recent theoretical and experimental developments in an active field of research, the foundations of quantum mechanics. The field is characterized by a dichotomy of unparalleled agreement between theory and experiment on the one hand, and an enormous variety of interpretations of the underlying mathematical formalism on the other hand. This proceedings of the "Enrico Fermi" Summer School of July 2016 contains 21 contributions on a range of topics: the history and interpretations of quantum theory; the principle of complementarity and wave-particle duality; quantum theory from first principles; the reality of the wave function; the concept of the photon; measurement in quantum theory; the interface of quantum theory and general relativity; and quantum optical tests of quantum theory.

This is the first book to comprehensively cover quantum probabilistic approaches to spectral analysis of graphs, an approach developed by the authors. The book functions as a concise introduction to quantum probability from an algebraic aspect. Here readers will learn several powerful methods and techniques of wide applicability, recently developed under the name of quantum probability. The exercises at the end of each chapter help to deepen understanding.

The book explores the variety of meanings of contextuality across different disciplines, with the emphasis on quantum physics and on psychology. Contents:Conversations on Contextuality (Ehtibar N Dzhafarov & Janne V Kujala)Contextual Semantics (Samson Abransky)From Coupling to Copula (Hans Colonius)Einstein, Bohm, and Leggett-Garg (Guido Bacciagaluppi)It is the Theory Which Decides What We Can Observe (Thomas Filk)Reality, Contextuality, and Probability in Quantum Theory and Beyond (Arkady Plotnitsky)Contextual Emergence (Harald Atmanspacher)Contextuality in Physics and Quantum Cognition (J Acacio de Barros & Gary Oas)End-Directedness and Context in Nonliving Dissipative Systems (James A Dixon, Dilip Kondepudi, Bruce A Kay & Tehran J Davis)Foregrounding the Background (J Scott Jordan, Jiuyang Bai, Vincent Cialdella & Daniel Schloesser)Symmetry-Breaking in Multiagent Coordination (Michael J Richardson & Rachel W Kallen)Probabilistic Contextuality (Janne V Kujala & Ehtibar N Dzhafarov)Quantum Thinking and Counterfactual Reasoning (Louis Narens)Quantum Theory, Active Information and the Mind-Matter Problem (Paavo Pylkkänen)Principles Defining Quantum Mechanics (Gary Oas & J Acacio de Barros)Our (Represented) World: A Quantum-Like Object (Ariane Lambert-Mogiliansky & Francois Dubois)Why Would You Want to Borrow from My Discipline? (Emmanuel Haven)Quantum Information Biology (Masanari Asano, Irina Basieva, Andrei Khrennikov, Masanori Ohya, Yoshiharu Tanaka & Ichiro Yamato)Similarity Judgments: From Classical to Complex Vector Psychological Spaces (Albert Barque Duran, Emmanuel M Pothos, James M Yearsley, James A Hampton, Jerome R Busemeyer & Jennifer S Trueblood)A Quantum Bayes Net Approach to Causal Reasoning (Jennifer S Trueblood, Percy K Mistry & Emmanuel M Pothos) Readership: Researchers in quantum physics, mathematical modelling and cognitive science. Key Features:It is historically the first book dedicated entirely to contextualityIt is interdisciplinary, involving quantum physicists, computer scientists, mathematicians, analytic philosophers, economists, and psychologistsIts chapters are written by leading specialists in these various fieldsKeywords:Contextuality;Quantum Physics;Psychology

Containing contributions from leading researchers in this field, this book provides a complete overview of this field from the frontiers of theoretical physics research for graduate students and researchers. It introduces the most current approaches to this problem, and reviews their main achievements.