DES strives to image as many galaxies as possible to map dark matter. This is possible because the gravity of dark matter plays an important role in controlling the distribution of these galaxies. From August 2013 to January 2019, dozens of scientists gathered together and used Chile’s four-meter telescope Victor M. Blanco telescope to measure the near-infrared sky.
There are two keys to create a map. The first is to simply observe the location and distribution of the Milky Way in the entire universe. This arrangement allows scientists to know where the dark matter concentration is highest.
The second is to observe the gravitational lensing effect, which is a phenomenon in which the light emitted by a galaxy is stretched by the gravitational force of dark matter as it moves in space. The effect is similar to looking through a magnifying glass. Scientists use gravitational lensing to infer how much actual space is occupied near dark matter. The more distorted the light, the more agglomerated dark matter.
The latest results take into account the first three years of the DES data, during 345 night observations, more than 226 million galaxies were observed. Niall Jeffrey, a researcher at University College London and the École Normale Supérieure de Paris, said: “We can now map a quarter of the dark matter in the southern hemisphere.”
Generally, the data is consistent with the so-called Standard Model of Cosmology, which assumes that the universe was formed in the Big Bang and its total mass energy content is 95% dark matter and dark energy. The new map provides scientists with more detailed information to understand some of the huge dark matter structures in the universe, otherwise we would not be able to see them. The brightest points on the map indicate the highest concentration of dark matter, and they form clusters and halos around voids with very low density.
But some results are surprising. Jeffrey said: “We found that the universe is smoother than expected.” “These hints can also be seen in other gravitational lensing experiments.”
This is not predictable by general relativity, which implies that dark matter should be more clumped and unevenly distributed.The author wrote In one of 30 papers Was released as “although the evidence is by no means absolute, but perhaps we are beginning to see hints of new physics.” Jeffrey said: “For cosmologists, “this may be equivalent to changing gravity as described by Einstein. law”.
Despite the great influence, caution is the most important, because we still know very little about dark matter (something we have not directly observed). For example, Jeffrey pointed out: “If nearby galaxies are arranged in a strange way in a straight line due to complex astrophysics, then our lens results will be misled.”
In other words, there may be some strange interpretations of the results—perhaps explaining them in a way consistent with general relativity. For any astrophysicist who has built his life on Einstein, this would be a great comfort. And please don’t forget: General Relativity is outstanding in the following aspects: Other tests It has been thrown to it all these years.
Even if there are more DES data versions to be released, the results have already caused a sensation. Jeffrey said: “Astronomers are already using these maps to study the structure of the cosmic web and to better understand the connection between galaxies and dark matter.” We may not have to wait too long to determine whether the results are really short-lived. , Or our understanding of the universe needs a lot of rewriting.