Phenomena currently attributed to Dark Matter (DM) and Dark Energy (DE) are merely a result of the interplay between gravitational energy density, caused by the contraction of space by matter, and space dilation, caused by the energy density of the C
osmological Microwave Background (CMB). This interplay causes inhomogeneous and anisotropic expansion, in and around galaxies, where as the expansion of the universe, when viewed globally, is homogeneous and isotropic. These contentions lead to a theoretical derivation of the gravitational central acceleration in and around galaxies, and the determination of g0, the central acceleration where falttening of Rotation Curves (RC) replaces Keplerian behavior. Our results, which fit the observed flattening of RCs, resemble the phenomenological Tully-Fisher and Millgrom MOND relations. However, our central acceleration, g0, depends on the CMB energy density at the time of formation of a galaxy and, as opposed to MOND, is not a universal constant.
