[en] In this report a mathematical formulation of fundamental concepts of unified geometrical theory of fundamental interactions is given. A concept of momentum of the gravitational field is introduced, equations of gravidynamics are derived, expressions for kinetic energy, potential energy and energy flow vector of the gravitational field are found. A most general form of the law of energy conservation is established, from which it follows that the hypothetical dark energy is the energy of the gravitational field. Two exact solutions of the equations of gravidynamics are obtained and their physical interpretation is given