This is only an assumption
I am not a scientist but I have an artistic eye and feeling. In the beginning there was no light, so the BB happened in total darkness. Dark matter is something that remained from that early universe and produce mass, static mass. I will not make here a long talk because I have made my point in my book1 why I came to the conclusion that dark matter is actually “pure space”, nothing with mass, or if you prefer the Higgs boson particle. In other words, we can change the view with a more common place and go deep into the ocean. The universe is like a big and ancient ocean of dark water. There is no light because this dark water does not react to our light, but it reacts to sound and waves. When the first particles started to form atoms they shield in some invisible staff and you can imagine some transparent balloons that are filled with water. Atoms are not empty, they are 99.9% filled with dark matter. But the problem with this “grandfather” of water is that it can’t be detected with today technology, even in the vacuum of space or even in the laboratory. Because the problem with a vacuum experiment is that you don’t actually have a vacuum. I just love the movie Iron Man and the reply that Tony Starks gives in the air to the bad guy “how did you solve the icing problem”. And this applies to modern science when someone say it has created a vacuum: “well, how did you solve the dark matter problem”. And to get a good image of the universe and dark matter, imagine that all the stars and planets are sunk into a tank of water. The vortices that are created by dark stars now make perfect sense and you can get a more natural picture of how “pure space” (water) is twisted around heavy spheres. So now is very simple to also picture the gravity wave created by every star and going all around the surface of the water. Gravity is not mass, is an effect of speeding mass over static mass. Basically the motion of atoms gives the mass inside them more mass and that’s how they can move inside this web of dark matter. And to this artistic picture, time is giving the motion. But time remains a mystery with a dual shape and form. You didn’t think that time is that simple as Einstein suggested. The artificial time which is captured by objects is the artificial side, the illusion of what’s about to hit us. But this I will keep a secret until it’s the right time. Remember that you see time, you do not record it. And to end this beautifully, think that as you gain speed on earth, you encounter air resistance that is slowing you down. On the contrary, out in space while you move, you encounter mass accumulation and the faster you go the heavier you become.