1. The repulsion law*
F = L0 Ｍｍｒ (1)
Where F is the repulsion on either body, M and m are their mass, r is distance between two centers-of-mass and Λ0 is the repulsion constant.
Suppose repulsion is like gravitation in that they have the same spread velocity.
It can be shown that, the repulsion exerted on or by a body is the same as if the mass of body were concentrated at its center-of-mass no matter what shape and size of the body.
The strength of the repulsion field is
L0 M ｒ (2)
* 《 The Expanding Universe 》 , A.S.Eddington, 1932 year.