Wigner-Type Theorems for Hilbert Grassmannians (London Mathematical Society Lecture Note Series, Series Number 460)

Wigner's theorem is a fundamental part of the mathematical formulation of quantum mechanics. The theorem characterizes unitary and anti-unitary operators as symmetries of quantum mechanical systems, and is a key result when relating preserver problems to quantum mechanics. At the heart of this book is a geometric approach to Wigner-type theorems, unifying both classical and more recent results. Readers are initiated in a wide range of topics from geometric transformations of Grassmannians to lattices of closed subspaces, before moving on to a discussion of applications. An introduction to all the key aspects of the basic theory is included as are plenty of examples, making this book a useful resource for beginning graduate students and non-experts, as well as a helpful reference for specialist researchers. "Wigner's theorem (67) provides a geometric characterization of unitary and anti-unitary operators as transformations of the set of rays of a complex Hilbert space, or equivalently, rank one projections. This statement plays an important role in mathematical foundations of quantum mechanics (11; 50; 63), since rays (rank one projections) can be identified with pure states of quantum mechanical systems. We present various types of extensions of Wigner's theorem onto Hilbert Grassmannians and their applications. Most of these results were obtained after 2000, but to completeness of the exposition we include some classical theorems closely connected to the main topic (for example, Kakutani-Mackey's result on the lattice of closed subspaces of a complex Banach space (31), Kadison's theorem on transformations preserving the convex structure of the set of states of quantum mechanical systems (30)). We use geometric methods related to the Fundamental Theorem of Projective Geometry and results in spirit of Chow's theorem (13)"-- Provided by publisher "Wigner's theorem (67) provides a geometric characterization of unitary and anti-unitary operators as transformations of the set of rays of a complex Hilbert space, or equivalently, rank one projections. This statement plays an important role in mathematical foundations of quantum mechanics (11; 50; 63), since rays (rank one projections) can be identified with pure states of quantum mechanical systems. We present various types of extensions of Wigner's theorem onto Hilbert Grassmannians and their applications. Most of these results were obtained after 2000, but to completeness of the exposition we include some classical theorems closely connected to the main topic (for example, Kakutani-Mackey's result on the lattice of closed subspaces of a complex Banach space (31), Kadison's theorem on transformations preserving the convex structure of the set of states of quantum mechanical systems (30)). We use geometric methods related to the Fundamental Theorem of Projective Geometry and results in spirit of Chow's theorem (13)"-- Résumé de l'éditeur Cover......Page 1 LONDON MATHEMATICAL SOCIETY LECTURE NOTE SERIES......Page 2 Wigner-Type Theorems for Hilbert Grassmannians ......Page 4 Copyright ......Page 5 Contents ......Page 6 Preface......Page 8 Introduction......Page 10 1 Two Lattices......Page 13 2 Geometric Transformations of Grassmannians......Page 31 3 Lattices of Closed Subspaces......Page 62 4 Wigner’s Theorem and Its Generalizations......Page 77 5 Compatibility Relation......Page 111 6 Applications......Page 134 References......Page 150 Index......Page 154