Astronomers from Japan using the Subaru telescope have built the most accurate and widest map of dark matter in existence. Putting together the data on gravitational lensing and the positions where dark matter should be located, they found that the simplest model of the expansion of the universe could be untenable. The article with the results is posted on the ArXiv preprint site.
Currently, approximately 80% of the substance in the Universe is a substance invisible to the eye, called dark matter. Images of distant galaxies obtained by modern instruments are distorted by gravitational fields created by dark matter. The attenuation of the signal from a distant galaxy is called photometric redshift. And if the gravitational lens is directly between the object and the observer, then the object, on the contrary, appears clear and magnified. With the help of distortions, it is possible to detect dark matter.
Subaru's Hyper Suprime-Cam survey helped create the most extensive 3D dark matter map in existence, although it is only 11% of the planned large-scale map so far. Scientists have calculated the number of halos from dark matter, the lensing effect of which exceeds a certain threshold value. According to these data, the amount of halos from dark matter is less than predicted by the Standard Model - the modern "theory of everything" that combines the structure of matter with the structure of the Universe.
This may be the weak point of the existing theory. Further observations and analysis will show whether there is a reason to abandon it, whether the Standard Model needs changes, and come closer to a better understanding of the mechanisms that make the universe expand.
