Field equations and relations

Field functions, 4-currents

Field equations

Divergences of field tensors, 4-currents

Motion equation

Products of field tensors and 4-currents or divergences of fields’ stress-energy tensors

Energy, Lagrangian, Hamiltonian

4-potentials, field tensors and 4-currents

Equation for the metric

The Ricci tensor, scalar curvature, fields’ stress-energy tensors

Gauge of 4-potentials

Divergences of 4-potentials

Continuity equations

Divergences of 4-currents, field tensors, the Ricci tensor