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A surprisingly large number of galaxies with masses of ~109–1010 at redshifts of are discovered with the James Webb Space Telescope. A possible explanation for the increase in the mass function can be the presence of a local maximum (bump) in the power spectrum of density perturbations on the corresponding scale. In this paper, it is shown that simultaneously with the growth of the mass function, galaxies from the bump region must have a higher density (compactness) compared to cosmological models without a bump. These more compact galaxies have been partially included in larger galaxies and have been subjected to tidal gravitational disruption. They have been less destructed than "ordinary" galaxies of the same mass, and some of them could survive to z = 0 and persist on the periphery of some galaxies. The formation and evolution of compact halos in a cube with a volume of (47 Mpc)3 with (1024)3 dark matter particles in the redshift range from 120 to 0 have been numerically simulated and observational implications of the presence of such galaxies in the current Universe have been discussed. [ABSTRACT FROM AUTHOR]

The merger rate of primordial black holes (PBHs) is numerically estimated by taking into account the gravitational interaction of PBHs with clustering cold dark matter (DM). The mass and initial separation have values appropriate for the explanation of LIGO/Virgo events by the merging of binary PBHs. We refine the criterion for the merging of a pair of black holes, provided that a DM halo is formed around each of them, and apply this criterion to a series of numerical simulations of the evolution of the Universe filled with both PBHs and DM. As a result, we show that taking the DM clustering into account increases the merger rate approximately by a factor of 10 compared to the standard estimate for a small fraction of PBHs in DM. This, in turn, implies that the PBH mass fraction may be smaller than assumed previously and may account for no more than of the total DM mass. [ABSTRACT FROM AUTHOR]

The entropy approach to the problem of the formation of a dark-matter halo is analyzed and verified. The model described predicts that the density profile of the halo is determined by the sum of the initial entropy associated with fluctuations of the matter density in the early Universe and the entropy generated in the course of the formation of the halo. The model also predicts the formation of halos without cusps in most galaxies with high initial entropy. Special numerical models are used to measure the initial entropy of the halo, which proves to be an order of magnitude lower than the values calculated using the linear theory, suggesting that most galactic-mass halos should possess cusps. [ABSTRACT FROM AUTHOR]

A device for mobilization of the greater pectoral muscle during endoprosthetic surgery was developed at the Samara Regional Clinical Oncology Center (Utility model patent No. 175229; November 28, 2017). The device makes the surgery less traumatic, reduces the volume of blood loss and the duration of surgery, and improves the quality of visualization of the surgical area. It allows the rate of injuries to the greater pectoral muscle to be reduced. [ABSTRACT FROM AUTHOR]