The solution to the gravitational field equations of a flat galaxy has been found. Itis shown that at the edge of the galaxy the excessively strong ordinary (unreduced)centrifugal pseudo-forces of inertia are compensated mainly by centripetal pseudoforcesof evolutionary self-contraction of matter in the background Euclidean spaceof expanding Universe, and not by the weak gravitational pseudo-forces at the edgeof the galaxy. The strength of the dynamic gravitational field of spiral and otherflat (or superthin) galaxies, according to their two-dimensional topology, isinversely proportional to the radial distance, not to its square. And this is the case,despite the inverse proportionality of the strength of individual gravitational fieldsof all spherically symmetric astronomical objects of the galaxy exactly to thesquare of radial distance. The general solution of the equations of the gravitationalfield of the galaxy with an additional certain parameter n is found. At possible valuesof n < 1, the velocity of the orbital motion of stars is slightly less than the highestpossible velocity even at the edge of the galaxy. According to the General Relativity(GR) equations and the Relativistic Gravithermodynamics (RGTD) equations, theconfiguration of the dynamic gravitational field of a flat galaxy in a quasi-equilibriumstate is standard (canonical in RGTD). That is because it is not determined at all by thespatial distribution of the average mass density of its non-continuous matter. After all,this spatial distribution of the average mass density of the galaxy's matter is itself determined by the standard configuration of its dynamic gravitational field. Thestandard value of the average density of mass of matter at the edge of a galaxy isdetermined by the cosmological constant Λ and by the difference between unityand the maximum value of the parameter bc. And it is a non-zero standard value,despite the gravitational radius at the edge of a galaxy takes the zero value.Therefore, in the RGTD and in the appropriate interpretation of the GR, in contrast tothe orthodox interpretation of the GR, there can be no shortage of baryonic mass. Andtherefore, the Universe does not need dark non-baryonic matter at all.