In this paper, we study the model of the late universe with the homogeneous, isotropic and flat Friedmann–Robertson–Walker metric, where the source of the gravitational field is based on the fermion and boson fields, with the Maxwell term [Formula: see text] in four dimensions. The actuation of the Maxwell term for the Einstein gravity makes it possible to find new approaches to solve the problem of the observed accelerated expansion of the universe. Energy conditions have been obtained and studied. These conditions impose very simple and model-independent restrictions on the behavior of energy density and pressure since they do not require a specific equation-of-state of matter. To consider the model, the energy conditions NEC, WEC, DEC are realized, and the SEC condition is violated. The boson and fermion fields are responsible for the accelerated regime at early times, but since the total pressure tends toward zero for large times, a transition to a decelerated regime occurs. Maxwell field is crucial only in the early times.
Now exist several alternative cosmological models that describe observable properties of our universe. In particular, it is such models as F (R) and F (T ) gravity. We consider properties of their generalization as F (R, T ) model of gravity with kessence. We obtained some exact solutions of particular cass of scale factor a for general formof the F (R, T ) functions with scalar field. These solutions describe the accelerated/deccelerated periods of the universe.
We considered the f(R) model of gravity with the Yang-Mills field and k-essence in four dimensions, together with the homogeneous, isotropic and flat Friedmann-Robertson-Walker universe. For this model we found equations of motion, a solution for a scale factor, a scalar field, a scalar potential is reconstructed, we studied the slow roll parameters. For the model under consideration, the of slow roll parameters satisfy the region of the inflationary stage. For later times was found the equation of state parameter ω, the deceleration parameter q the value of which corresponds to the accelerated expansion of the universe. Our model allows you to get an accelerated expansion of the universe in the inflationary period. Over time, the field decreases, rolls off slowly, viscosity has a lesser effect, and the universe leaves the inflationary regime, which shows the exponential dynamics of changes in the law of expansion of the universe.
энергиялық 103 Rh ядросындағы (р,хр) реакциясынның екiншi реттiк протондар эмиссиясы 8 Аралбаева Г.М., Гиниятова Ш.Г. TiO 2-де латенттi тректердiң параметрлерiн бағалауға арналған термиялық шыңның моделi Жексембаева А., Абуова Ф.У., Ақылбеков А.Т., Абуова А.У., Сарсебай Е. LaM nO 3 кристалының (001) бетiндегi процестердi кванттық механикалық модельдеу Мейрамбай А., Ержанов К.К., Ержанова Ж.О. Фейнмандық диаграммалар толық интегралданатын статистикалық тор жүйесi ретiнде Аумаликова М., Ибраева Д., Жумадилов К., Шишкина Е., Бахтин М., Кашкинбаев Е. Уран өндiретiн және өңдейтiн кәсiпорындарда жұмыс iстейтiн қызметкерлер мен тұрғылықты халықтың дозалық жүктемесiн есептеу Ибраева А.Д. Si 3 N 4-те тректүзiлу механизмiн сипаттау үшiн термиялық шыңның серпiмсiз моделiнiң қолдануын зерттеу Мырзакулов Н.А., Мырзакулова Ш.А., Мейрбеков Б.К. (2+1) өлшемдi F (T) гравитациясының фермиондық өрiспен байланысқандағы космологиялық шешiм Рахымбеков А.Ж. Суперионды өткiзгiштегi электрлiк өткiзгiштiктi есептеу Сарсенова С.М., Степаненко В.Ф., Жумадилов К.Ш. Оптикалық стимуляцияланған люминесценттiк (ОСЛ) дозиметрия әдiсiнiң қазiргi жағдайы
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