An international team of researchers has presented the most complete map of dark matter. They found that the universe may be slightly smoother than previously thought.
Researchers have created the largest ever map of dark matter, an invisible material believed to account for 80% of all matter in the universe. Scientists noted that since matter bends space-time, astronomers can determine its existence by observing light coming towards Earth from distant galaxies. If the light is distorted, it means that there is matter in the foreground that bends the light.
The Dark Energy Survey (DES) research team used artificial intelligence (AI) to analyze images of 100 million galaxies, studying their shape for stretching. The new map is an image of all the matter found in the foreground of the observed galaxies and covers a quarter of the sky in the southern hemisphere.
“On our map, which mainly represents dark matter, we see the same picture as when observing only visible matter – a cobweb-like structure with dense clusters of matter separated by large empty voids,” the researchers noted. “Observing these cosmic-scale structures can help us answer fundamental questions about the universe.”
For decades, astronomers have suspected that there is more matter in the universe than we can observe. Dark matter, like dark energy, remains a mystery, but its existence can be judged by the fact that galaxies behave in unpredictable ways. For example, this is evidenced by the fact that galaxies stick together, and galaxies within clusters are moving faster than expected.
“Visible galaxies form in the densest regions of dark matter. When we look at the night sky, we see the light of the galaxy, but not the surrounding dark matter, as if we were looking at the lights of a night city. By calculating how gravity distorts light, a technique known as gravitational lensing, we get a complete picture of both visible and invisible matter, “the scientists noted.
The researchers concluded that matter is distributed throughout the universe in a way that is consistent with the predictions of the standard cosmological model (ΛCDM), the best modern model of the universe. But the researchers also found signs that the universe could be several percent smoother than predicted.