Search results
Results from the WOW.Com Content Network
The Schwinger's quantum action principle is a variational approach to quantum mechanics and quantum field theory. [1] [2] This theory was introduced by Julian Schwinger in a series of articles starting 1950. [3]
Schwinger's foundational work on quantum field theory constructed the modern framework of field correlation functions and their equations of motion. His approach started with a quantum action and allowed bosons and fermions to be treated equally for the first time, using a differential form of Grassman integration.
Action principles are the basis for Feynman's version of quantum mechanics, general relativity and quantum field theory. The action principles have applications as broad as physics, including many problems in classical mechanics but especially in modern problems of quantum mechanics and general relativity.
Therefore, the source appears in the vacuum amplitude acting from both sides on the Green's function correlator of the theory. [1] Schwinger's source theory stems from Schwinger's quantum action principle and can be related to the path integral formulation as the variation with respect to the source per se corresponds to the field , i.e. [6]
This is the starting point of Schwinger’s treatment of the theory of quantum angular momentum, predicated on the action of these operators on Fock states built of arbitrary higher powers of such operators. For instance, acting on an (unnormalized) Fock eigenstate,
Path Integral Methods in Quantum Field Theories. Cambridge University Press. V.P. Nair (2005). Quantum Field Theory A Modern Perspective. Springer. There are some review article about applications of the Schwinger–Dyson equations with applications to special field of physics. For applications to Quantum Chromodynamics there are
The Osterwalder–Schrader theorem [4] states that Euclidean Schwinger functions which satisfy the above axioms (E0)-(E4) and an additional property (E0') called linear growth condition can be analytically continued to Lorentzian Wightman distributions which satisfy Wightman axioms and thus define a quantum field theory.
It is also referred to as the Sauter–Schwinger effect, Schwinger mechanism, or Schwinger pair production. It is a prediction of quantum electrodynamics (QED) in which electron – positron pairs are spontaneously created in the presence of an electric field, thereby causing the decay of the electric field.