The solution to the gravitational field equations of a flat galaxy has been found.It is shown that at the edge of the galaxy the excessively strong ordinary (unreduced)centrifugal pseudo-forces of inertia are compensated mainly by centripetalpseudo-forces of evolutionary self-contraction of matter in the backgroundEuclidean space, and not by the weak gravitational pseudo-forces at the edge ofthe galaxy. The strength of the dynamic gravitational field of spiral and otherflat (or superthin) galaxies, according to their two-dimensional topology, is inverselyproportional to the radial distance, not to its square. And this is thecase, despite the inverse proportionality of the strength of individual gravitationalfields of all spherically symmetric astronomical objects of the galaxy exactlyto the square of radial distance. The general solution of the equations of thegravitational field of the galaxy with an additional certain parameter n is found. Atpossible values of n < 1, the velocity of the orbital motion of stars is slightly lessthan the highest possible velocity even at the edge of the galaxy. According to theGeneral Relativity (GR) equations and the Relativistic Gravithermodynamics(RGTD) equations, the configuration of the dynamic gravitational field of a galaxyin a quasi-equilibrium state is standard (canonical in RGTD). That is because it isnot determined at all by the spatial distribution of the average mass density of itsnon-continuous matter. After all, this spatial distribution of the average mass densityof the galaxy's matter is itself determined by the standard configuration of its dynamicgravitational field. The standard value of the average mass density of matterat the edge of a galaxy is determined by the cosmological constant Λ andthe difference between unity and the maximum value of the parameter bc. Andit is a non-zero standard value, despite the gravitational radius at the edge of agalaxy takes the zero value. Therefore, in the RGTD, in contrast to the GR, therecan be no shortage of baryonic mass.