Quantum electrodynamics, or QED, concept in theoretical physics. It concerns the motions and relationships between charged electrical particles including electrons, positrons, and photons and their interaction with electrical and magnetic fields. QED allows highly accurate predictions of changes in the properties of these particles. Physicists Richard P. Faynman and Julian S. Schwinger of the United States and Sin-itiro Tomonaga of Japan contributed in the 1940s to the development of QED.
See also: Feynman, Richard Phillips.