Special Astrophysics Colloquium 2026

Every physicist and astronomer has heard about "The First Three Minutes" in the life of our Universe, when 25% of helium and much lower abundances of deuterium, helium-3, and even lithium for our electrical batteries were synthesized. I will discuss the time when any additional energy release (for example, the decay or annihilation of unknown types of dark matter particles, evaporation of primordial black holes, or formation of the first accreting supermassive black holes) will start to leave traces on the spectrum of the Cosmic Background Radiation. And there are some chances of detecting these very peculiar spectral distortions originating when the Universe was already older than 18 years, or 380 thousand years, or even a few billion years. I plan to remind you of well-known and simple physical processes that should lead to the creation of such spectral distortions. Even more, huge ground-based millimeter telescopes on the South Pole and in the high-altitude Atacama Desert discovered already "shadows" on the CMB sky due to one of these CMB spectral distortions in the directions to the 22 000 clusters of galaxies filled by dark matter, the hot (up to 100 million degrees) intercluster gas and many hundreds of galaxies. And two different groups of Munich and Garching astrophysicists, using these millimeter telescopes and the eRosita X-ray telescope (which is also able to detect the hot gas in clusters of galaxies) are now competing to observe when and how the population of these clusters of galaxies with huge masses between 1014 and 1015 solar masses (consisting mainly of dark matter) was born and is growing. It will be good to remind you how Fritz Zwicky discovered this "dunkel Materie" in the Coma cluster of galaxies using Caltech telescopes at the beginning of the 1930s! The Astrophysical community agreed with him only in the 1970s after different confirmations discovered by Vera Rubin and many other great astronomers and radio astronomers. I will try to explain to you how astronomers have now proven that clusters of galaxies are receding from us due to the Hubble flow with relativistic velocities, but their velocity relative to the CMB surrounding each cluster is several hundred times lower. This follows from theoretical cosmology based on GR, but now there is the experimental proof.