nLab
vacuum diagram

Contents

Context

Vacua

Algebraic Quantum Field Theory

algebraic quantum field theory (perturbative, on curved spacetimes, homotopical)

Introduction

Concepts

field theory:

Lagrangian field theory

quantization

quantum mechanical system, quantum probability

free field quantization

gauge theories

interacting field quantization

renormalization

Theorems

States and observables

Operator algebra

Local QFT

Perturbative QFT

Contents

Idea

A Feynman diagram without external edges is called a vacuum diagram.

For example the simplest vacuum diagram obtained from the electron-photon interaction in quantum electrodynamics is

In the computation of scattering amplitudes in a stable vacuum the contribution of the vacuum diagrams to the Feynman perturbation series cancels out.

For details see at S-matrix this section

Last revised on May 17, 2019 at 16:09:00. See the history of this page for a list of all contributions to it.