Rebuilt the distribution of dark matter at the dawn of the universe, around galaxies that we see today as they were 12 billion years ago: a journey back in record time (so far it had reached 10 billion years ago), which suggests that some fundamental laws of cosmology may not hold close to the Big Bang.
This is indicated by a study published in the journal Physical Review Letters by a team led by Hironao Miyatake of the University of Nagoya in Japan, in collaboration with the University of Tokyo, the National Astronomical Observatory of Japan and Princeton University.
To reconstruct the map of the elusive dark matter, the researchers exploited the background radiation in microwaves (Cosmic Microwave Background, Cmb): in particular, they studied how this residue of the fossil light of the Big Bang is deformed by the gravitational lens effect. generated by the dark matter surrounding one and a half million galaxies visible today (due to the finite speed of light) as they appeared 12 billion years ago.
Using data from the European Space Agency's (ESA) Planck Space Telescope and observations from the Subaru Hyper Suprime-Cam Survey (Hsc), it was therefore possible to map dark matter as it was 1.7 billion years after the Big Bang. .
One of the most interesting findings that emerged from the study concerns the density of dark matter, which would have been lower than that predicted by the Lambda-Cdm model.
If this is further confirmed, it would mean that the model does not adequately describe what happened shortly after the Big Bang.
