Scientists have observed the dark matter that existed around galaxies 12 billion years ago. This is the earliest period in which this mysterious matter has been recorded.
Dark matter is the invisible substance that makes up the majority of all matter in the universe. This component observed by scientists dates back to the period 2 billion years after the Big Bang. Their paper was published in the journal Physical Review Letters on Monday.
“For the first time in history, we estimate the amount of dark matter present in almost the earliest moments of the universe,” said Yuichi Harikane, one of the co-authors of the study and an assistant professor at the University of Tokyo. In the present, the first clusters of galaxies also begin to form.”
Although dark matter makes up about 27% of the universe, astronomers cannot observe it directly, in part because it does not emit light. Instead, researchers can observe the gravitational influence that dark matter has on the visible matter (even galaxies).
Scientists used a technique called gravitational lensing to estimate the curvature of the universe’s first light. The Cosmic Microwave Background (CMB) is the radiation left over from the Big Bang that spreads throughout space. The study’s authors selected 1.5 million galaxies to act as a gravitational lens for their unity and then studied the curvature of these ancient remnants. In this way, they were able to reconstruct the distribution of dark matter in galaxies.
Scientists have found that the dark matter of the early universe may not be as cohesive as current models of physics suggest.
“Our finding is still unclear,” said Hironao Miyatake, co-author of the study and a cosmologist at Nagoya University, “but if true, it may indicate that there are some flaws in the overall model as we go further back in time.”
According to the scientist, the event is exciting, because if it remains valid even after the reduction of inaccuracies, it may lead to the improvement of the model, which will provide us with additional information about the nature of dark matter itself.