quantum electrodynamics

quantum theory of electromagnetic radiation and its interaction with atom particles and electrically charged atoms (Quantum Mechanics)

Quantum electrodynamics (QED) is a relativistic quantum field theory of electrodynamics. QED was developed by a number of physicists, beginning in the late 1920s. QED mathematically describes all phenomena involving electrically charged particles interacting by means of exchange of photons. It has been called "the jewel of physics" for its  extremely accurate predictions of quantities like the anomalous magnetic moment of the electron, and the Lamb shift of the energy levels of hydrogen.
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Noun
1. a relativistic quantum theory of the electromagnetic interactions of photons and electrons and muons
(synonym) QED
(hypernym) quantum field theory