Shereta E., Carraro G., Gorbaneva T., Mishenina T. «Molybdenum abundance in some open clusters» Публикации Одесской астрономической обсерватории (Odessa Astronomical Publications, Украина), 31, с. 100-102 (2018)

https://doi.org/10.18524/1810-4215.2018.31.144691

Chernin A.D., Karachentsev I.D., Emelyanov N.V. «Zeldovich local pancake: dark energy domination» Публикации Одесской астрономической обсерватории (Odessa Astronomical Publications, Украина), 31, с. 11-14 (2018)

https://doi.org/10.18524/1810-4215.2018.31.144435 Zeldovich Local Pancake is a two-dimensional system of 15 giant galaxies nearest to us. Two of the galaxies, the Milky Way and the Andromeda Galaxy, move to each other in the Local Group, while the rest of the galaxies are located around the group at the distances up to 10 Mpc from the group barycenter and move away from it forming a local expansion outflow. We use recent Hubble Space Telescope data on local giants and their numerous fainter companions to study the dynamical structure and evolutionary trends of the expanding system. N-body computer model, which reproduces the observed kinematics of the flow, is constructed under the assumption that the system as a whole is embedded in the universal dark energy background. In the model, the motions of the flow bodies are controlled by their mutual attraction force and the repulsion force produced by the dark energy. It is found that the repulsion dominates the force field of the system. Because of this, the the system expands with acceleration. The dark energy domination increases with time and introduces to the expansion flow an asymptotically linear velocity-distance relation with the universal time-rate (the Hubble constant) that depends on the dark energy density only

Chernogor L.F., Garmash K.P., Zhdanko Y.H., Leus S.G., Luo Y. «Features of ionospheric effects from the partial solar eclipse over the city of Kharkiv on 10 June 2021» Радиофизика и радиоастрономия (Украина), 26, № 4, с. 326-343 (2021)

Purpose: Solar eclipses pertain to high-energy sources of disturbance in the subsystems of the Sun–interplanetary-medium–magnetosphere–ionosphere–atmosphere–Earth and the Earth–atmosphere–ionosphere–magnetosphere systems. During the solar eclipse, the coupling between the subsystems in these systems activates, and the parameters of the dynamic processes become disturbed. Investigation of these processes contributes to understanding of the structure and dynamics of the subsystems. The ionospheric response to the solar eclipse depends on the season, local time, magnitude of the solar eclipse, phase of the solar cycle, the observation site, the state of space weather, etc. Therefore, the study of the effects, which each new solar eclipse has on the ionosphere remains an urgent geophysics and radio physics problem. The purpose of this paper is to describe the radio wave characteristics and ionospheric parameters, which accompanied the partial solar eclipse of 10 June 2021 over the City of Kharkiv. Design/methodology/approach: To make observations, the means of the HF Doppler measurements at vertical and oblique incidence available at the V. N. Karazin Kharkiv National University Radiophysical Observatory were employed. The data obtained at the “Lviv” Magnetic Observatory were used for making intercomparison. Findings: The radiophysical observations have been made of the dynamic processes acting in the ionosphere during the solar eclipse of 10 June 2021 and on the reference days. The temporal variations in the Doppler frequency shift observed at vertical and oblique radio paths have been found to be, as a whole, similar. Generally speaking, the Doppler spectra over these radio propagation paths were different. Over the oblique radio paths, the number of rays was greater. The solar eclipse was accompanied by wave activity enhancement in the atmosphere and ionosphere. At least three wave trains were observed. The values of the periods (about 5–12 min) and the relative amplitudes of perturbations in the electron density (δ_N≈0.3–0.6%) give evidence that the wave disturbances were caused by atmospheric gravity waves. The amplitude of the 6–8-min period geomagnetic variations has been estimated to be 0.5–1 nT. Approximately the same value has been recorded in the X component of the geomagnetic field at the nearest Magnetic Observatory. The aperiodic effect of the solar eclipse has appeared to be too small (less than 0.01 Hz) to be observed confidently. The smallness of the effect was predetermined by an insignificant magnitude of the partial eclipse over the City of Kharkiv (no more than 0.11). Conclusions: The features of the solar eclipse of 10 June 2021 include an insignificant magnitude of the aperiodic effect and an enhancement in wave activity in the atmosphere and ionosphere.

Chervon S.V., Fabris J.C., Fomin I.V. «Spherical symmetric solutions of f(r) gravity with a kinetic curvature scalar» Пространство, время и фундаментальные взаимодействия, № 1, с. 53-65 (2020)

We consider modified f/(R) gravity with a kinetic curvature scalar as a chiral self-gravitating model in a spherically symmetric spacetime. Most attention devoted to finding solutions for special case of scaling transformation when modified gravity transforms to Einstein frame from Jordan one. We proposed the method of determination of kinetic function for given scalar field dependence on space coordinate. New classes of solutions are found for special choice of f/(R) function.

Fomin I.V., Chervon S.V., Maharaj S.D. «Application of the Schrödinger equation in exact scalar field cosmology» Пространство, время и фундаментальные взаимодействия, № 2, с. 83-94 (2020)

We propose a new method of exact solutions construction for scalar field cosmology based on representation of the Einstein–Friedmann dynamic equations as Schrödinger-like one. This representation allows one to compare the solutions of quantum-mechanical and cosmological problems. On the other hand, this approach makes it possible to use the well-known form-invariant transformations of the Schrödinger equation to generate exact cosmological solutions. As an example of the application of this method, the use of the Darboux transformations in scalar field cosmology is considered. On the other hand, the presented methods make it possible to generalize the obtained solutions to multi-field cosmological models.

Ivanov G.G., Chervon S.V., Khapaeva A.V. «Friedmann cosmological model with nonlinear scalar field» Пространство, время и фундаментальные взаимодействия, № 3, с. 66-71 (2020)

This paper is a translation of work Ivanov G.G. "Friedmann cosmological model with nonlinear scalar field" of 1981

Chornogor S.N., Kondrashova N.N. «Multi-wavelength observations of a large solar flare» Публикации Одесской астрономической обсерватории (Odessa Astronomical Publications, Украина), 32, с. 114-118 (2019)

https://doi.org/10.18524/1810-4215.2019.32.182447