A quantum action principle for open systems
type: Item
instance of: scholarly article
title: A quantum action principle for open systems
zbMATH Open document ID: 0866.49040
DOI: 10.1007/BF00343193
author: Michael Thoss
author: Berthold-Georg Englert
published in: Letters in Mathematical Physics
publication date: 1997-07-08T00:00:00Z
review text: Schwinger's remarkable contributions to the various areas of theoretical physics are quite well known. Particularly, his quantum action principle (QAP) leads to a nice, compact formulation of quantum mechanics. It is of great value as a powerful tool for computational physics apart from its intrinsic interest in general. However, in its original form QAP is limited to closed systems. It is now sought to be generalized to the open systems as well, through the present rather long letter under review. Starting with the essentials of QAP of Schwinger, the principle in Hilbert space is re-formulated in the Liouville space. An extension of QAP to open systems with time evolution via Markovian dynamics is given. It is then illustrated by means of a driven, damped harmonic oscillator. The new action principle provides for a differential characterization of the Green's function for the master equation as against Schrödinger equation. A short heuristic derivation of the extended QAP, following Schwinger's original method, is also added. On the whole, the work breaks fresh and useful ground which must have far-reaching consequences.
Mathematics Subject Classification ID: 49S05
Mathematics Subject Classification ID: 82C10
Mathematics Subject Classification ID: 81V80
zbMATH DE Number: 922364
zbMATH Keywords: quantum action principle
zbMATH Keywords: open systems with time evolution
zbMATH Keywords: Markovian dynamics
MaRDI profile type: Publication
full work available at URL: https://doi.org/10.1007/bf00343193
OpenAlex ID: W2075974665
description: scientific article; zbMATH DE number 922364