Quantum electrodynamics

Summary

Quantum electrodynamics, or QED, is the quantum field theory of electrons, positrons and light. It is the gauge theory with gauge group $U(1)$ in which a Dirac field is coupled to the electromagnetic potential. Its predictions are computed by perturbation theory with Feynman diagrams and renormalization, and some of them agree with experiment to about ten significant digits. Feynman, Schwinger and Tomonaga received the 1965 Nobel Prize in Physics for its formulation.