On changes in the rate of expansion of space
In the first moments after the Big Bang, stretching the space of the universe occurred maximally rapidly, and the distance between the points grew from those microscopic to, possibly, exceeding the visible today region of space whose size is about fifteen gigaparsecs. Then, distances began to rise more slowly, as the square root of time, and after about 100 thousand years, in proportion to the time to the degree two thirds. The change of the rate of expansion of the universe occurred when the density of electromagnetic radiation and neutrinos became less than the density of dust-like matter — relatively slow protons, neutrons and electrons. When the universe was about five and a half billion years, the space has expanded so much that the density of particles — in the form of atoms, they had already made up stars and intergalactic gas — has given way to the density of the dark energy, so the expansion rate has begun to rise.