Propagator in polymer quantum field theory

The semiclassical propagator in field theory

We consider scalar field theory in a changing background field. As an example we study the simple case of a spatially varying mass for which we construct the semiclassical approximation to the propagator. The semiclassical dispersion relation is obtained by consideration of spectral integrals and agrees with the WKB result. Further we find that, as a consequence of localization, the semiclassic...

Quantum EM Field and Photon Propagator

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...

Irreversibility in Quantum Field Theory

It is shown how the programme of decoherence can be applied in the context of quantum field theory. To illustrate the role of gauge invariance, we first discuss the charge superselection rule in quantum electrodynamics in some detail. We then present an example where macroscopic electromagnetic fields are “measured” through interaction with charges and thereby rendered classical. A central role...

Spin in Quantum Field Theory

I introduce spin in field theory by emphasizing the close connection between quantum field theory and quantum mechanics. First, I show that the spin–statistics connection can be derived in quantum mechanics without relativity or field theory. Then, I discuss path integrals for spin without using spinors. Finally, I show how spin can be quantized in a path–integral approach, without introducing ...