Comparison of theoretical and experimental data on the advance of the mercury perihelion: The proper contribution of the gravitational field of the sun to the perihelion advance

An expression for the angular displacement of planets caused by their Newtonian interaction with each other is derived. In some cases, numerical results that follow from it differ from those published earlier (without specifying from where and how they were obtained). As a consequence, the remainder of the relativistic gravitational advance of the Mercury perihelion (after the observational data analysis) exceeds the value that was known before by more than one and a half times and follows from general relativity. However, this remainder value is in a very good agreement with the theoretical value that occurs if i) we acknowledge the material nature of the gravitational field of the Sun and ii) we uncover its physical contribution to the matter energy-momentum tensor in the Hilbert-Einstein equations.