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Information × Registration Number 0225U002720, (0124U001660) , R & D reports Title Cosmic rays of ultrahigh energies: acceleration mechanisms, potential astrophysical sources and multimessenger manifestations popup.stage_title Механізми прискорення космічних променів надвисоких енергій (КПНВЕ). Head Zhdanov Valerii I., Доктор фізико-математичних наук Registration Date 01-04-2025 Organization Taras Shevchenko National University of Kyiv popup.description1 Determination of nature and identification of sources of ultrahigh energy cosmic rays (UHECR); improvement of models of relativistic objects taking into account the effects of “new physics”, which arise from the study of UHECR and their multimessenger manifestations in energy ranges beyond the standard theory. popup.description2 Models of acceleration of ultrahigh-energy cosmic rays (UHECR) have been developed for a number of astronomical objects. The results are new, of world level; they are of interest for planning observations with gamma-ray telescopes of a new generation (within the framework of the CTA consortium) and for differentiating mechanisms of UHECR generation (in particular, decay or annihilation of dark matter particles). An explanation of the observed spectral flux of gamma-rays in the direction of the source 4FGL J1908.6+0915e has been found, taking into account recent observations with new supernova remnants. It is significant that the energy budget required for the explanation corresponds to typical energies of Galactic Supernovae (about 1051 erg); this is more adequate in comparison with known earlier. The spectra of electromagnetic radiation in different ranges have been calculated. The results are new and of world level. The stability and other qualitative properties of static spherically symmetric solutions in quadratic f(R) gravity (Starobinsky model) have been analyzed, which is often used to describe the early inflation of the Universe. This has been applied to describe isolated relativistic objects. Regions of linear stability and instability with respect to small radial perturbations have been found. The results are new and of world level; they significantly refine previously known results in this area and show the ways of further research. Estimates of the angular and energy distribution of scattered high-energy muons of cosmic origin in environments with characteristic parameters inherent in the problem of studying the melt under the fourth reactor of the Chernobyl NPP have been obtained. The feasibility and realism of applying muon tomography to this problem are shown. It is estimated that the typical observation time to obtain an image from one location is about 100 days with existing technical means. Product Description popup.authors Babur Valentyna М. Hnatyk Bohdan I. Huhnin Oleksandr Е. Mozhova Alona M. Shtаnov Yurii V. popup.nrat_date 2025-04-01 Close