where G and Λ Λ are constants. The first term is the familiar law of universal gravitation, the second one corresponds to the cosmological constant term in general relativity and McCrea-Milne cosmology. Then the field is force-free only in the center of a shell but the confinement (oscillator) term does not change the initial O ( 4 ) symmetry of the Newtonian field. Also, this field corresponds to the only field possessing the property of the Newtonian one: the closing of orbits at any negative value of energy, i.e. the coincidence of the period of variation of the value of the radius vector with that of its revolution by 2 π π (resonance principle).