As part of real-life mathematical modelling processes, classical field equations are accompanied by other equations of motion, equations of state, constitutive equations, and continuity equations. Quantum field equation In quantum field theory, particles are described by quantum fields which satisfy the Schrödinger equation. They are also creation and annihilation operators which satisfy commutation relations and are subject to the spin–statistics theorem. Particular cases of relativistic quantum field equations include the Klein–Gordon equation for spin-0 particles the Dirac equation for spin-1/2 particles the Bargmann–Wigner equations for particles of any spin In quantum field equations, it is common to use momentum components of the particle instead of position coordinates of the particle's location, the fields are in momentum space and Fourier transforms relate them to the position representation. See also Field strength Wave function Fundamental interaction Field coupling Field decoupling Coupling parameter Vacuum solution References General Classical field theory Quantum field theory Classical and quantum field theory External links Theoretical physics Mathematical physics Applied mathematics Partial differential equations Classical field theory Quantum field theory