We begin by discussing how Feynman diagrams enter into particle physics.įeynman diagrams are used in perturbation theory to mathematically approximate a difficult to compute quantum calculation through a series expansion. It’s more difficult to turn them into definite integrals, and then to evaluate the integrals is yet worse. It’s fairly easy to write down Feynman diagrams. Maybe this can work as a short introduction to the method for those who haven’t seen it before. Accordingly, we will skim over a lot of details, but will include links to articles that will explain further, if needed.Īs a first step, let’s describe what is so difficult about the usual way of doing Feynman diagrams. I will try to write this introduction at a low enough level, and with enough links to explanations of the jargon, that it can be understood by people unfamiliar with particle physics. This post will discuss Feynman diagrams the usual way. For a reference in the arXiv literature, see Quantum Electrodynamics for Qubits, but our discussion will be simpler than this. He meant the “masses of physicists.” Between this post and the next, we’re going to take Feynman one better and make Feynman diagrams accessible to the masses, as in “masses of amateurs.” Our simplification will be to use qubits. Julian Schwinger complained that Feynman had made QFT accessible to the “masses”. In the 1940s, Richard Feynman and Ernest Stueckelberg independently developed a notation (now known as Feynman Diagrams), that greatly ease certain calculations in QFT.
If you want to win a Nobel Prize in Physics by finding the unified field theory, it’s pretty obvious that you will have to learn how to make Quantum field theory (QFT) calculations.