On the action principle in quantum field theory
نویسنده
چکیده
An analysis of the Schwinger’s action principle in Lagrangian quantum field theory is presented. A solution of a problem contained in it is proposed via a suitable definition of a derivative with respect to operator variables. This results in a preservation of Euler-Lagrange equations and a change in the operator structure of conserved quantities. Besides, it entails certain relation between the field operators and their variations (which is identically valid for some fields, e.g. for the free ones). The general theory is illustrated on a number of particular examples. Bozhidar Z. Iliev: Action principle in QFT 1
منابع مشابه
Exploring the implications of the laws and principles of quantum physics in the field of talent (quantum theory of talent)
The issue of talent-discovering is one of the most important issues in the field of education and research that has always been a concern for educational systems. Studying the issues of identifying and guiding talented students can illuminate a large part of the activities of the executors and practitioners in order to accomplish their mission effectively. On the other hand, quantum physics has...
متن کاملThe Quantum Action Principle in the framework of Causal Perturbation Theory
Abstract. In perturbative quantum field theory the maintenance of classical symmetries is quite often investigated by means of algebraic renormalization, which is based on the Quantum Action Principle. We formulate and prove this principle in a new framework, in causal perturbation theory with localized interactions. Throughout this work a universal formulation of symmetries is used: the Master...
متن کاملLASERS WITHOUT INVERSION: DENSITY OPERATOR METHOD
A quantum theory of a two and three-level laser with injected atomic coherence is developed by using a density operator method, to the best of our knowledge, for the first time. The initial atomic coherence plays an essential role. At steady state, the equation of motion for the density operator yields to exhibit laser without inversion and a phase locking but no threshold for the laser fie...
متن کاملA DFT and Molecular Dynamics Study on Inhibitory Action of Three Amine Derivatives on Corrosion of Carbon Steel
Inhibition efficiencies of three amine derivatives (Diethylenetriamine (I), Triethylenetetramine (II), and Pentaethylenehexamine (III)) have been studied on corrosion of carbon steel using density functional theory (DFT) method in gas phase. Quantum chemical parameters such as EHOMO (highest occupied molecular orbital energy), ELUMO (lowest unoccupied molecular orbital energy), hardness (η), po...
متن کاملThe Feynman Variational Principle in the Worldline Representation of Field Theory
Following Feynman’s treatment of the non-relativistic polaron problem, similar techniques are used to study relativistic field theories: after integrating out the bosonic degrees of freedom the resulting effective action is formulated in terms of particle trajectories (worldlines) instead of field operators. The Green functions of the theory are then approximated variationally on the pole of th...
متن کامل