3. Strong interaction

Multiplying (17) to (- 4p), where  - Newton's gravitational constant, we get for intensity + = - 4pD of gravitational field

(1-U/c2) divE + EgradU/c2 = (1-U/c2)2, (18)

where E= E0 (1-U/c2).
In the linear theory of a field it is supposed
E0= -gradU0 , (19)
inserting in into (12à), we get Poisson's equation
     ,     (20)
where  div grad .
But in gravitation due to E= E0 (1-U/c2) and U=U0 (1-U/c2) from (19) results that

E = (- gradU)/(1 - U/c2) = (- gradU0)/(1 + U0 /c2)    (21)

and U0 = U/(1-U/c2) or U=U0 /(1 + U0 /c2). (22)
So putting (21) instead of (18), we finally get
(1-U/c2)U = 4pr (1-U/c2)3-2(U)2/c2, (23)

where  grad.

Of course the same result may be received while putting (22) instead of (20).
If we take into account the possible motion of gravitationally interacting objects with velocities v1 and v2, then on the background of (15) è (21) we finally get the system of gravitational field equations in the form

                  (1 - U/c2)E = -gradU (24)

or either in the form

.    (25)
It can be done in a simpler way with the use of (20) for determining U0 and putting the result in (22) taking into account kinematics:
.      (26)
In particular, for the case of point-like mass in statics we have for the potential
U0 = -m/r è U = -mc2/(rc2 -m), (27)
and for the tensity of gravitational field
E0 = -m/r2 è E = (-mc2)/(rc2 -m)r. (28)
From (27) it results, that at mass annihilation, when radius r of a body becomes nil there generates energy
W = mU = mc2,    (29)
i.e. there is a trivial conclusion of mass and energy being equivalent without any Einshtein's mystique.
As it comes from (28), at small, if compared to m/c2, body radius r the force effecting the trial mass changes its character, i.e. attractions is replaced by repulsion. In the whole the force behaviour near r =m/c2 resembles strong interaction which it most apparently is. This obviously indicates the gravitational nature of strong interaction becoming classical Newton's gravitation U " U0 and E  " E0 at big, if compared to m/c2, distances r from the field source.
It can be supposed that (28) in cosmology describes, on the first hand, the behaviour of pulsars the mass of which shrinks when r >m/c2, and explodes when r becomes less than m/ñ2.

On the other hand, (28) describes "black holes" as a state of bodies sized r =m/c2 or a little bigger, when their attraction is close to infinity.

We have yet to consider that in addition there are quantum effects in micro particles describing, in the form

E=[-(m + hc/m)c2] /[(rc2-m-hc/m)r] , (30)

where h- Plank's constant not revaling itself in macroscopic physics, i.å. at  kg. Though otherwise U= -hc2/(rcm - h) and
E = - hc2/(rcm - h)r, and the border where attraction becomes repulsion is r = h/mc.
Finally let us note that for spherically symmetric source moving with velocity v1 and the experimenter moving with velocity v2 we have instead of (28) the following

, (31)

which reduces the radius of the attraction transfer into repulsion in macroscopic physics but hough does not effect microphysics.
Anyway the particular solvatiion (23) looks like
, (32)
where from for spheric symmetry we obtain (27).
In dynamics the gravitational field potential from the sense of logic would have to be delaying , where ñ* - seeming (measurable) velocity of gravitational field distribution, but if the field spreads in reality with velocity ñ, then according to (11) for any experimenter always , i. å. there exists no delaying gravitational potential the same as there exist no gravitational waves.

Beside this, in all the correlations of the gravitational field there acts electromagnetic constant c, and this fact indicates electromagnetic origin of gravitation on one hand, and on the other hand makes us to suggest that gravitation is distributed by means of electromagnetic waves.

This also can be prooved by the fact that, according to (17) and as it has already been stated the source of gravitational field can be either in mass or in energy of the field itself, which may seem absurd if we do not suppose that gravitational and electromagnetic energies are identical. Then the absence of gravitational waves can be reasoned, for their function of field transmission is performed by of electromagnetic waves.