Equation of Vlasov–Maxwell–Einstein type and transition to a weakly relativistic approximation

The gravitational Lagrangian of general relativity is considered together with the Lagrangian of electromagnetism. Vlasov-type equations are derived from the former in the general, nonrelativistic, and weakly relativistic limits. Expressions for the resulting corrections to the Poisson equation are proposed, which may contribute to the effective action of dark matter and dark energy.