Orthogonality and Quantum Geometry Towards a Relational Reconstruction of Quantum Theory Shengyang Zhong Orthogonality and Quantum Geometry Towards a Relational Reconstruction of Quantum Theory ILLC Dissertation Series DS-2015-03 For further information about ILLC-publications, please contact Institute for Logic, Language and Computation Universiteit van Amsterdam Science Park 107 1098 XG Amsterdam phone: +31-20-525 6051 e-mail: [email protected] homepage: http://www.illc.uva.nl/ The investigations were supported by the China Scholarship Council (CSC). Copyright (cid:13)c 2015 by Shengyang Zhong Cover design by Shengyang Zhong. Printed and bound by GVO drukkers & vormgevers B.V. ISBN: 978-90-6464-894-6 Orthogonality and Quantum Geometry Towards a Relational Reconstruction of Quantum Theory Academisch Proefschrift ter verkrijging van de graad van doctor aan de Universiteit van Amsterdam op gezag van de Rector Magnificus prof.dr. D.C. van den Boom ten overstaan van een door het college voor promoties ingestelde commissie, in het openbaar te verdedigen in de Aula der Universiteit op woensdag 9 september 2015, te 11.00 uur door Shengyang Zhong geboren te Guangdong, China. Promotor: Prof. dr. J.F.A.K. van Benthem Co-promotor: Dr. A. Baltag Dr. S.J.L. Smets Overige leden: Dr. N. Bezhanishvili Prof. dr. R.I. Goldblatt Prof. dr. J.R. Harding Prof. dr. Y. Venema Prof. dr. R.M. de Wolf Prof. dr. M. Ying Faculteit der Natuurwetenschappen, Wiskunde en Informatica Contents Acknowledgments ix 1 Introduction 1 1.1 Introduction: Logics of Quantum Theory . . . . . . . . . . . . . . 1 1.1.1 A Brief Survey of Quantum Logic . . . . . . . . . . . . . . 2 1.1.2 Motivation of the Thesis . . . . . . . . . . . . . . . . . . . 8 1.1.3 Outline of the Thesis . . . . . . . . . . . . . . . . . . . . . 9 1.1.4 Acknowledgement of Intellectual Contributions . . . . . . . 12 1.2 The Hilbert Space Formalism of Quantum Mechanics . . . . . . . 12 1.2.1 Quantum Systems and Hilbert Spaces . . . . . . . . . . . . 13 1.2.2 Observables and Self-Adjoint Operators . . . . . . . . . . . 14 1.2.3 Evolution and Unitary Operators . . . . . . . . . . . . . . 15 1.2.4 Composite Systems and Tensor Products . . . . . . . . . . 16 2 Quantum Kripke Frames 19 2.1 Definitions and Examples . . . . . . . . . . . . . . . . . . . . . . 19 2.1.1 Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 2.1.2 Examples . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 2.2 State Spaces . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 2.3 Geometric Frames . . . . . . . . . . . . . . . . . . . . . . . . . . . 28 2.3.1 From Geometric Frames to Projective Geometries . . . . . 29 2.3.2 From Projective Geometries to Geometric Frames . . . . . 32 2.3.3 Correspondence . . . . . . . . . . . . . . . . . . . . . . . . 34 2.4 Complete Geometric Frames . . . . . . . . . . . . . . . . . . . . . 37 2.4.1 Saturated Sets in Geometric Frames . . . . . . . . . . . . 37 2.4.2 Complete Geometric Frames and Hilbertian Geometries . . 41 2.4.3 Finite-Dimensionality . . . . . . . . . . . . . . . . . . . . . 42 2.5 (Quasi-)Quantum Kripke Frames . . . . . . . . . . . . . . . . . . 46 2.6 Subframes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50 v 2.6.1 Subframes of a Geometric Frame . . . . . . . . . . . . . . 51 2.6.2 Subframes of a (Quasi-)Quantum Kripke Frame . . . . . . 52 2.7 Quantum Kripke Frames in Quantum Logic . . . . . . . . . . . . 54 2.7.1 Quantum Kripke Frames and Hilbert Spaces . . . . . . . . 54 2.7.2 Piron Lattices and Other Quantum Structures . . . . . . . 67 2.7.3 Classical Frames . . . . . . . . . . . . . . . . . . . . . . . 71 2.8 Historical Notes . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73 3 Maps between Quantum Kripke Frames 79 3.1 Continuous Homomorphisms . . . . . . . . . . . . . . . . . . . . . 80 3.1.1 Definition and Basic Properties . . . . . . . . . . . . . . . 80 3.1.2 Special Continuous Homomorphisms . . . . . . . . . . . . 85 3.2 Parties of Homomorphisms . . . . . . . . . . . . . . . . . . . . . . 91 3.2.1 Rulers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 92 3.2.2 The Comrades of a Homomorphism . . . . . . . . . . . . . 97 3.2.3 Parties of Homomorphisms . . . . . . . . . . . . . . . . . . 102 3.3 Orthogonal Continuous Homomorphisms . . . . . . . . . . . . . . 106 3.3.1 Uniformly Scaled Rulers . . . . . . . . . . . . . . . . . . . 106 3.3.2 Trace of a Continuous Homomorphism . . . . . . . . . . . 113 3.3.3 Three Assumptions . . . . . . . . . . . . . . . . . . . . . . 116 3.3.4 (Non-)Orthogonality between Continuous Homomorphisms 118 4 Logics of Quantum Kripke Frames 123 4.1 First-Order Definability in Quantum Kripke Frames . . . . . . . . 124 4.1.1 Infinite-Dimensional or -Codimensional Sets . . . . . . . . 125 4.1.2 Automorphisms of a Quasi-Quantum Kripke Frame . . . . 127 4.1.3 The Main Theorem . . . . . . . . . . . . . . . . . . . . . . 131 4.1.4 Application . . . . . . . . . . . . . . . . . . . . . . . . . . 133 4.2 Undecidability in Quantum Kripke Frames . . . . . . . . . . . . . 135 4.2.1 The Decision Problem for Fields . . . . . . . . . . . . . . . 135 4.2.2 The Decision Problem for Quantum Kripke Frames . . . . 136 4.2.3 The Decision Problem for Piron Lattices . . . . . . . . . . 144 4.3 Modal Logics of State Spaces . . . . . . . . . . . . . . . . . . . . 145 4.3.1 Axiomatization of State Spaces . . . . . . . . . . . . . . . 145 4.3.2 Axiomatization of State Spaces with Superposition . . . . 148 4.3.3 Decidability . . . . . . . . . . . . . . . . . . . . . . . . . . 151 5 Probabilistic Quantum Kripke Frames 155 5.1 Definition and Basic Properties . . . . . . . . . . . . . . . . . . . 156 5.2 Probabilistic Quantum Kripke Frames and Hilbert Spaces . . . . . 157 5.3 Connection with Quantum Probability Measures . . . . . . . . . . 160 5.4 Quantum Kripke Frames That Can Be Probabilistic . . . . . . . . 166 5.5 Quantum Transition Probability Spaces . . . . . . . . . . . . . . . 169 vi 6 Conclusion 173 6.1 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 173 6.2 Future Work . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 177 A Quantum Structures 185 B Geometry and Algebra 189 B.1 Projective Geometry . . . . . . . . . . . . . . . . . . . . . . . . . 189 B.1.1 Basic Notions in Projective Geometry . . . . . . . . . . . . 189 B.1.2 Dimensions in Projective Geometry . . . . . . . . . . . . . 191 B.1.3 Projective Geometries with Additional Structures . . . . . 193 B.1.4 Maps between Projective Geometries . . . . . . . . . . . . 196 B.2 Linear Algebra . . . . . . . . . . . . . . . . . . . . . . . . . . . . 198 B.2.1 Division Rings and Vector Spaces . . . . . . . . . . . . . . 198 B.2.2 Hermitian Forms on Vector Spaces . . . . . . . . . . . . . 201 B.2.3 Maps between Vector Spaces . . . . . . . . . . . . . . . . . 203 B.3 Correspondences . . . . . . . . . . . . . . . . . . . . . . . . . . . 205 B.3.1 Projective Geometries and Vector Spaces . . . . . . . . . . 205 B.3.2 Orthogonality and Hermitian Forms . . . . . . . . . . . . . 208 B.3.3 Homomorphisms and Linear Maps . . . . . . . . . . . . . 211 B.4 Harmonic Conjugate . . . . . . . . . . . . . . . . . . . . . . . . . 213 C Linear Maps 217 C.1 Adjoint of a Linear Map . . . . . . . . . . . . . . . . . . . . . . . 217 C.2 Trace of a Linear Map . . . . . . . . . . . . . . . . . . . . . . . . 218 C.3 The Structure of Hom(V ,V ) . . . . . . . . . . . . . . . . . . . . 221 1 2 C.4 Orthogonal Basis without Eigenvectors . . . . . . . . . . . . . . . 223 Bibliography 227 Index 235 Samenvatting 241 Abstract 245 vii