In the course of research, Japanese scientists discovered the presence of mysterious dark matter, enveloping clusters of galaxies that already existed 12 billion years ago. They appeared 1.8 billion years after the birth of the universe. As Space writes, scientists have come to the conclusion that dark matter in the early universe is not concentrated in dense areas in space, as described in modern cosmic models. And if their theory is confirmed, it could completely change the understanding of the evolution of galaxies. Scientists also believe that it is quite possible that 12 billion years ago the laws of space were completely different.
Dark matter does not interact with light or matter. Therefore, it is very difficult to detect. Astronomers must rely on its interaction with gravity to find it.
Objects that have a huge mass, according to Einstein’s theory, cause a distortion of space-time. Galaxy clusters or galaxies can be just such objects, and can be used as a lens to observe the light sources behind them. This process is called gravitational lensing.
By observing how the light from a source behind a galaxy changes, researchers can study the distribution of dark matter. The larger it is, the more the galaxy distorts the light.
Since early galaxies are far away and very faint, they are difficult to study using this method. Before that, scientists were unable to study the distribution of dark matter in them. But in their new study, they used relic radiation, the oldest source of light in the universe left over from the Big Bang. It is distorted by lensing galaxies.
It is thanks to relict radiation that researchers managed to look into the early history of the universe. According to Yuichi Harikane from the University of Tokyo, this made it possible to measure dark matter in galaxies that are already 12 billion years old.
According to scientists, at that time the forming galaxy cluster was gravitationally bound to a large amount of dark matter. At the same time, in the early universe, it did not create dense areas in space. If this theory is correct, it will change the way we think about the universe and force researchers to reconsider theories about the nature of dark matter.