Bohmian Mechanics, Open Quantum Systems and Continuous Measurements

This book shows how Bohmian mechanics overcomes the need for a measurement postulate involving wave function collapse. The measuring process plays a very important role in quantum mechanics. It has beenwidely analyzed withinthe Copenhagen approach through the Born and von Neumann postulates, with later extension due to Lüders.In contrast, much less effort has beeninvested in the measurement theory within the Bohmian mechanics framework. The continuous measurement (sharp and fuzzy, or strong and weak) problem is considered herein this framework. The authors beginbygeneralizing the so-called Mensky approach, which is based on restricted path integral through quantum corridors. The measuring system is then considered to be an open quantum system following a stochastic Schrödinger equation. Quantum stochastic trajectories (in the Bohmian sense)and their role inbasic quantum processes are discussed in detail. The decoherence process is thereby described in terms of classicaltrajectories issuing from the violation of the noncrossing rule of quantum trajectories.