Wigner on Foundations of Quantum Mechanics

Valerian I. Tatarskii

Chamila Chandrabanu Ekanayake

This paper presents a critical review of the Wigner’s Friend thought experiment and its modern extensions within quantum mechanics. The study explores observer-dependent reality, measurement theory, quantum state assignment, and interpretational challenges arising from nested observers in quantum systems. Particular attention is given to the Frauchiger–Renner argument and its implications for the consistency of single-world interpretations of quantum mechanics. The paper discusses conceptual tensions between unitarity, observer perspectives, and objective reality, while examining possible resolutions proposed in contemporary quantum foundations research. This work is intended as an independent scholarly review aimed at contributing to discussions in quantum foundations and quantum information theory.

Hans Primas, Michaël Esfeld

Review of "The Collected Works of Eugene Paul Wigner", Volume I, III, and VI. Excerpt from the Conclusions: Many of Wigner’s papers on mathematical physics are great classics. Most famous is his work on group representations which is of lasting value for a proper mathematical foundation of quantum theory. The modern development of quantum theory (which is not reflected in Wigner’s work) is in an essential way a representation theory (e.g. representations of kinematical groups, or representations of C*-algebras). This view owes very much to Wigner’s seminal papers on the unitary representations of compact and noncompact groups. Wigner showed much courage in relating the then unresolved questions of the measurement problem to the much deeper problem of consciousness. In view of this very unorthodox proposal it is astonishing that Wigner was very reactionary with respect of the dogmas of orthodox quantum mechanics. In contrast to von Neumann himself, he took the old von-Neumann codification of quantum mechanics as authoritative and not to be questioned. Much of the efforts to interpret the meaning of this codification and to prove no-go theorems, such as the insolubility of the measurement problem or the impossibility of a quantum theory of individual objects, are physically irrelevant since they are based on a codification of quantum mechanics that is valid only for strictly closed systems with finitely many degrees of freedom. However, in nature there are no such systems. Every material system is coupled to the gravitational and to the electromagnetic field – systems which require in a Hamiltonian description infinitely many degrees of freedom. A deeper insight into the conceptual problems of quantum theory is possible only if the modern development of a quantum theory of infinite systems is taken into account.

Erhard Scheibe

Heinz Dietrich Doebner, Wolfgang Scherer, Franklin E. Schroeck

The Wigner Symposia series emerged from an International Symposium On SpaceTime Symmetries, held in College Park, Maryland, 1988 organized by Y.S. Kim and W. Zachary and commemorating the 50'th anniversary of Wigner's fundamental paper On the Unitary Representation of the Inhomogenous Lorentz Group. That symposium covered various areas of physics, of theoretical and mathematical physics to which Eugene Paul Wigner has contributed. It has shown how new and fruitful ideas connected with symmetries for a mathematical modeling of complex physical systems developed under the influence of Wigners work. Following the idea of the symposia to discuss new developments in physics centered around fundamental questions topics with emphasis on theoretical and mathematical physics were chosen and new frontiers like neuronal networks and quantum holography, whose origins can be traced back to Wigner's work, where included. The aim was to show the unity of different parts in physics and to demonstrate the power of arguments which are directly or indirectly related with mathematical realizations of symmetries. (1) Foundations of Quantum Mechanics; (2) General group Theoretical and Quantization Methods; (3) Coherent States; (4) Berry Phases; (5) Phases Space and Wigner Distributions; (6) Applications of Quantum Mechanics From Channel Space to Wigner Crystal; (7) Quantum Fields and Particles; (8) C-Algebraic and Methods; (9) Differential Geometric Methods: and (10) Nonlinear Partial Differential Equations, Dynamical Systems and Neural Networks.

Roderich Tumulka