Quantum Field Theory joins ideas from quantum theory and special relativity. There are multiple field theories that apply to different forces:
| Theory | Force |
|---|---|
| QED: Quantum Electrodynamics | Electromagnetic force |
| QCD: Quantum Chromodynamics | Strong nuclear force |
| Electroweak Theory | Weak nuclear force |
There is yet to be found a quantum theory of gravity. A good overview over attempts made to unify physical theories is provided by the cGh cube, seen in the diagram below:
stateDiagram
SpecialRelativity
QuantumFieldTheory
TheoryOfEverything
QuantumMechanics
NonRelativisticQuantumGravity
ClassicalMechanics
Gravitation
GeneralRelativity
ClassicalMechanics --> Gravitation : Add gravity
QuantumMechanics --> NonRelativisticQuantumGravity : Add gravity
QuantumFieldTheory --> TheoryOfEverything : Add gravity
SpecialRelativity --> GeneralRelativity : Add gravity
ClassicalMechanics --> QuantumMechanics : Add spoky action
Gravitation --> NonRelativisticQuantumGravity : Add spoky action
SpecialRelativity --> QuantumFieldTheory : Add spoky action
GeneralRelativity --> TheoryOfEverything : Add spoky action
ClassicalMechanics --> SpecialRelativity : Add space-time curvature
QuantumMechanics --> QuantumFieldTheory : Add space-time curvature
Gravitation --> GeneralRelativity : Add space-time curvature
NonRelativisticQuantumGravity --> TheoryOfEverything : Add space-time curvature