Cosmic expansion acceleration and negative matter

To explain galactic flat rotation curves, I proposed in a previous paper to introduce a new “cosmic expansion acceleration,” with Newton’s gravity being unchanged. In this paper, this acceleration is applied to 3D radially symmetric systems. It is found that it is equivalent to a precise negative mass repartition, acting as Newtonian (anti-) gravity. It is shown that the transverse velocity remains constant, due to the transverse part of the acceleration. The model can be applied to (expanding or imploding) radial systems made of gas, dust, stars, or galaxies. Concerning the universe, it is applied in the two cases of exponential expansion and accelerated expansion. It is shown that the model is in conformity with the present observed data, and the needed mass densities are computed. The energy balance is also examined (showing that the expansion acceleration work and mass erosion combine to contribute to the increase in the total mass), together with the proportion of radial/lateral force works. The model predicts an equal amount of positive and negative masses in the “inner” regions of the universe, but an excess of negative masses in the outskirts, which could explain the observed bubbles with “empty” spaces in the large-scale regions. It opens the way to the easiest simulation of the expansion acceleration influence. More generally, this proposal appears to be an alternative to the other models used to describe the same phenomena, such as dark matter and energy and modified Newtonian dynamics (MOND).