The dark matter map raises questions about the Universe

Scientists from the Dark Energy Survey have just released the most detailed dark matter map to date. This, however, absolutely does not answer all the questions we have always asked about the Universe, indeed, from today the cosmos could hide more mysteries than before about its nature and its continuous expansion. As BBC News, Nature and Fermilab report (you can read one of the articles at this link), the five thousand square degree survey used weak gravitational lenses (in this case, how the gravity of nearby galaxies affects the views of distant ones) to search large patches of dark matter, in relatively close sections of the universe. The results were surprising because they show how dark matter is slightly more fluid and more diffuse than current theories predicted. The observation seems to move away from Einstein's theory of general relativity, posing a puzzle for researchers.

Dark matter is an invisible substance that permeates space. It represents 80% of the matter in the Universe. Astronomers were able to figure out where it was because it distorts the light from distant stars, so the greater the distortion, the greater the concentration of dark matter. Dr Niall Jeffrey, of the École Normale Supérieure in Paris, who reconstructed the map, said the result posed a "real problem" for physics.

"If this disparity is true, then maybe Einstein was wrong," the scientist told BBC News. “You might think this is a bad thing, that perhaps physics has reached a point of no return. But for a physicist, it's extremely exciting. It means that we can discover something new about the Universe ".

The data have also helped studies on dark energy, the still inexplicable force that seems to accelerate the expansion of the universe. The team produced a 3D map thanks to redshift, which is the tendency of objects to appear more and more red with distance. Team members conducted observations using the five hundred and seventy megapixel camera of the Victor M. Blanco telescope at the Cerro Tololo observatory in Chile. The experiments and measurements in question took place between 2013 and 2019.

While the high detail is useful, it also validated concerns that have been floating around for years. The DES results indicate that the universe is slightly more uniform than expected. While this largely supports current theories that dark energy is a constant, the discrepancy is enough that researchers may have to rethink existing ideas. The universe may not behave exactly as scientists thought and the dark matter map could lead to new models that question previous hypotheses.