A team of researchers from the University of Stockholm in Sweden has just proposed a revolutionary idea: the Big Bang event was not only big at the beginning of the universe, but could be accompanied by a second Big Bang in a few weeks. later, the ‘dark Big Bang’, which flooded the Universe with dark matter particles. According to Katherine Freese and Martin Wolfgang Winkler, whose work can be found on the arXiv server, the idea could also be tested experimentally.
In the picture of standard cosmology, the early Universe was a truly alien place, where the biggest thing after the Big Bang was an expansion event that pushed the entire universe into a period of very rapid expansion. When the inflation ended, much of the exotic fields that precipitated the event were thrown down, causing a fallout of particles and radiation that we can still see today.
Less than 20 minutes after the Big Bang, these particles began to come together to form the first protons and neutrons in what physicists have called cosmological nucleosynthesis, or the “Big Bang,” one of the pillars of today’s theories of how it is possible. to accurately predict the amount of hydrogen and helium in the cosmos.
However, all that glitters is not gold, and despite the success of our image of the ancient universe, we still do not understand dark matter, another form of matter that is five times more abundant than ordinary matter (from which stars and galaxies are made) and which in total accounts for about 27% of the mass of the universe (another 5% is normal matter and the remaining 68% is dark energy).
The prevailing idea is that the same processes that give rise to particles and rays must have generated dark matter at the same time. After this, the dark matter, which does not penetrate into the ordinary matter or emits any rays, just walks along, ignoring everything else.
by the way of law
But Freese and Wolfgang Winkler propose a completely different story in their paper: Big Bang inflation and nucleosynthesis was not the only thing that happened at the beginning of the universe, and dark matter could have evolved along a completely separate trajectory. In this new scenario, at the end of inflation, the Universe was indeed flooded with normal particles and radiation, but not dark matter. In its place was left as much field as that which did not perish. Then, as the universe expanded and cooled, beyond the extent of even the transformed field, the formation of dark matter arose.
The advantage of this approach is that it decouples the evolution of dark matter from conventional matter, so that Big Bang nucleosynthesis is possible, as we now understand it, and dark matter evolved along the way.
The new theory also opens the way to exploring the variety of dark matter theory, because, with its evolutionary trajectory, it is easier to follow in calculations how well it matches observations. For example, Freese and Wolfgang Winkler were able to determine that if the Big Bang really was Dark, it would have occurred when the Universe was less than a month old.
The research also found that this “second Big Bang” generated a unique type of gravitational waves, circles in the very fabric of space-time, which moreover persisted in the present universe and could be detected in some ongoing experiments. .
If these gravitational waves are detected, the theory will be confirmed and we will have a Universe with two different Big Bangs.