= Feynman diagram
{c}
{wiki}
I think they are a tool to calculate the probability of different types of particle decays and particle collision outcomes. TODO Minimal example of that.
And they can be derived from a more complete <quantum electrodynamics> formulation via <perturbation theory>.
Can be used for all of <quantum electrodynamics>, <weak interaction> and <quantum chromodynamics>.
At <Richard Feynman Quantum Electrodynamics Lecture at University of Auckland (1979)>, an intuitive explanation of them in termes of sum of products of <propagators> is given.
* https://www.youtube.com/watch?v=fG52mXN-uWI The Secrets of Feynman Diagrams | Space Time by <PBS Space Time> (2017)