Variational Principle for Fokker-Planck Cosmic Rays Transport Equation

Classical field theory is the generalization of particle mechanics and continuous systems. Typical situations involve a continuous approach suitable for fluid mechanics, electromagnetism and general relativity. Although the fields will provide all the physical information that's needed for observation , a theory with the intent to describe the nature must be available to explain the relation between field quantities and observables like energy, momentum and the flows therefore. This work is the propose a Lagrangian density for obtaining the Fokker-Planck cosmic rays transport equation. By creating this "cosmic ray transport field", it is possible to apply the No ether's theorem to find the energy-momentum tensor and currents of a single cosmic ray source.