Lawrence Horwitz - Böcker

This book focuses on unstable systems both from the classical and the quantum mechanical points of view and studies the relations between them. The first part deals with quantum systems. Here the main generally used methods today, such as the Gamow approach, and the Wigner-Weisskopf method, are critically discussed. The quantum  mechanical Lax-Phillips theory developed by the authors, based on the dilation theory of Nagy and Foias and its more general extension to approximate semigroup evolution is explained.The second part provides a description of approaches to classical stability analysis and introduces geometrical methods recently developed by the authors, which are shown to be highly effective in diagnosing instability and, in many cases, chaotic behavior. It is  then shown that, in the framework of  the theory of symplectic manifolds, there is a systematic algorithm for the construction of a canonical transformation of any standard potential model Hamiltonian to geometric form, making accessible powerful geometric methods for stability analysis in a wide range of applications.

This book focuses on unstable systems both from the classical and the quantum mechanical points of view and studies the relations between them. The first part deals with quantum systems. Here the main generally used methods today, such as the Gamow approach, and the Wigner-Weisskopf method, are critically discussed. The quantum  mechanical Lax-Phillips theory developed by the authors, based on the dilation theory of Nagy and Foias and its more general extension to approximate semigroup evolution is explained.The second part provides a description of approaches to classical stability analysis and introduces geometrical methods recently developed by the authors, which are shown to be highly effective in diagnosing instability and, in many cases, chaotic behavior. It is  then shown that, in the framework of  the theory of symplectic manifolds, there is a systematic algorithm for the construction of a canonical transformation of any standard potential model Hamiltonian to geometric form, making accessible powerful geometric methods for stability analysis in a wide range of applications.

The mechanics of Newton and Galileo is based on the postulate of a universal time which plays the role of an evolution parameter as well as establishing dynamical correlations between interacting systems. The Michelson-Morley experiment, explained by Einstein in terms of Lorentz transformations, appeared to imply that the time is not absolute, but rather suffers from changes when a system is in motion. Einstein's thought experiment involving a moving system and a laboratory frame of observation, however, indicates that the action of the Lorentz transformation corresponds to an observed effect recorded in the laboratory on a clock that must be running in precise synchronization with that of the observed system. Therefore one concludes that there must be a universal time, as postulated by Newton, and the time that suffers Lorentz transformation becomes an observable dynamical variable. This book describes the effect this observation had on the development of the theory of Stueckelberg, Horwitz and Piron, and the corresponding conceptual basis for many phenomena which can be described in a relativistically covariant framework.