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.
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.
- www.youtube.com/watch?v=fG52mXN-uWI The Secrets of Feynman Diagrams | Space Time by PBS Space Time (2017)
No, but why?
Articles by others on the same topic
A Feynman diagram records a term in the perturbative expansion: edges represent propagators, vertices represent interactions, and loops represent unconstrained momentum integrals.
A Feynman diagram is a graphic representation used in quantum field theory to visualize and analyze the behavior of subatomic particles during interactions. Named after physicist Richard Feynman, these diagrams depict the interactions between particles, such as electrons, photons, and gluons, in a way that makes complex calculations more manageable. In a typical Feynman diagram: - **Lines** represent the particles.