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Information × Registration Number 0223U004712, 0123U102923 , R & D reports Title Dark matter and dark energy in cosmological and astrophysical systems popup.stage_title Head Zhdanov Valerii І., Доктор фізико-математичних наук Registration Date 30-11-2023 Organization Taras Shevchenko National University of Kyiv popup.description2  Models of astrophysical objects described by spherically symmetric statistical solutions of Einstein's equations with a scalar field (SP) were studied. Cases of monotonic and non-monotonic SP potentials are considered. Numerical solutions for different types of potentials were obtained; asymptotic expressions in the vicinity of the bare singularity are found. Equations for linear disturbances of the axial type against the background of a static spherically symmetric configuration with a scalar field (the case of a power potential) have been obtained. The correctness of the initial problem for axial disturbances is proved and the stability of the configuration with respect to this type of disturbances is shown. The conditions for the existence of a spherically symmetric self-gravitating pion configuration have been analyzed. Based on the thermodynamic relations for the boson-fermion system, the equation of state for various parameters was obtained and analyzed. Numerical solutions of the Tolman-Oppenheimer-Volkov equations were obtained for these state equations. Equations for perturbations of thermodynamically non-equilibrium non-relativistic and relativistic distribution functions were obtained. A qualitative analysis was conducted and a list of qualitative differences was given in the evolution of a homogeneous anisotropic Bianchi type I cosmological model with an arbitrary equation of state in the presence of viscous matter within the framework of the general theory of relativity. The possibility of transition from expansion to compression, isotropization is analyzed, and a list of all possible types of singularities in the future for Bianchi's Type II cosmological model is presented. Product Description popup.authors Parnovskyi Serhii L. popup.nrat_date 2023-11-30 Close