Theory that brings quantum mechanics and special relativity together to account for subatomic phenomena.
In particular, the interactions of electromagnetic field . However, the fields are quantized and represented by particles, such as photons for the electromagnetic field. Quantum electrodynamics is the quantum field theory that describes the interaction of electrically charged particles via electromagnetic fields. Quantum chromodynamics describes the action of the strong force . The electroweak theory , a unified theory of electromagnetic and weak forces , has considerable experimental support, and can likely be extended to include the strong force. Theories that include the gravitational force (see {{link=gravitation">gravitation ) are more speculative. See also grand unified theory , unified field theory .