Автор(ы): Мырзакулов Р.*

Объем документа: С. 2075-2081

МРНТИ: 41.29.25

Ключевые слова: модели космологические*динамика темной материи*скалярные области*динамические системы уравнений*критические точки*аттракторы*параметры замедления модели*

Реферат: In this paper, we introduce a non-minimally conformally coupled scalar field and dark matter in F(T) cosmology and study their dynamics. We investigate the stability and phase space behavior of the parameters of the scalar field by choosing an exponential potential and cosmologically viable form of F(T). We found that the dynamical system of equations admits two unstable critical points; thus no attractor solutions exist in this cosmology. Furthermore, taking into account the scalar field mimicking quintessence and phantom energy, we discuss the corresponding cosmic evolution for both small and large times. We investigate the cosmological implications of the model via the equation of state and deceleration parameters of our model and show that the late-time Universe will be dominated by phantom energy and, moreover, phantom crossing is possible. Our results do not lead to explicit predictions for inflation and the early Universe era.

Автор(ы): Мырзакулов Р.*

Объем документа: С. 1998

МРНТИ: 41.29.25

Ключевые слова: космология типа Бьянки*теория гравитации*калибровочная симметрия Нетер*функции Лагранжа*космологическая мера пространства-времени*

Реферат: In this paper, we investigate the generalized Saez-Ballester scalar-tensor theory of gravity via Noether gauge symmetry (NGS) in the background of Bianchi type I cosmological spacetime. We start with the Lagrangian of our model and calculate its gauge symmetries and corresponding invariant quantities. We obtain the potential function for the scalar field in the exponential form. For all the symmetries obtained, we determine the gauge functions corresponding to each gauge symmetry which include constant and dynamic gauge. We discuss cosmological implications of our model and show that it is compatible with the observational data.

Автор(ы): Мырзакулов Р.*

Объем документа: 

МРНТИ: 41.29.25

Ключевые слова: модели космологические*модель темной энергии*стабильность фазового пространства*динамические уравнения Фридмана*критические точки*аттракторы*

Реферат: In this paper, we examine the interacting dark energy model in f(T) cosmology. We assume dark energy as a perfect fluid and choose a specific cosmologically viable form f(T). We show that there is one attractor solution to the dynamical equation of f(T) Friedmann equations. Further we investigate the stability in phase space for a general f(T) model with two interacting fluids. By studying the local stability near the critical points, we show that the critical points lie on the sheet in the phase space, spanned by coordinates. From this critical sheet, we conclude that the coupling between the dark energy and matter.

Автор(ы): Мырзакулов Р.*

Объем документа: С. 473-479

МРНТИ: 41.29.25

Ключевые слова: модели космологические*модели темной энергии*степенные энтропии*уравнение замедления модели*уравнения параметра плотности*

Реферат: We investigate the new agegraphic dark energy (NADE) model with power-law corrected entropy in the framework of Ho\v{r}ava-Lifshitz cosmology. For a non-flat universe containing the interacting power-law entropy-corrected NADE (PLECNADE) with dark matter, we obtain the differential equation of the evolution of density parameter as well as the deceleration parameter. To study parametric behavior, we used an interesting form of state parameter as function of redshift $\omega_{\Lambda}(z)=\omega_0+\omega_1 z$. We found that phantom crossing occurs for the state parameter for a non-zero coupling parameter, thus supporting interacting dark energy model.

Автор(ы): Jamil M.*Momeni D.*Myrzakulov R.*

Объем документа: P. 1-10

МРНТИ: 41.29.25

Ключевые слова: модели космологические взаимодействующие*модели темной энергии*аттракторы*космологическая константа*квинтэссенция*призрачная энергия 222*

Реферат: In this paper, we explore the cosmological implications of interacting dark energy model in a torsion-based gravity namely f(T). Assuming that dark energy interacts with dark matter and radiation components, we examine the stability of this model by choosing different forms of interaction terms. We consider three different forms of dark energy: cosmological constant, quintessence and phantom energy. We then obtain several attractor solutions for each dark energy model interacting with the other components. This model successfully explains the coincidence problem via the interacting dark energy scenario.

Автор(ы): Мырзакулов Р.*

Объем документа: С. 2427-2432

МРНТИ: 41.29.17

Ключевые слова: уравнения Гамильтона - Якоби*вселенная Геделя*моды Клейна - Гордона*спины нулевые*

Реферат: In this letter we investigate the separability of the Klein-Gordon and Hamilton-Jacobi equation in Godel universe. We show that the Klein-Gordon eigen modes are quantized and the complete spectrum of the particle\'s energy is a mixture of an azimuthal quantum number, m and a principal quantum number, n and a continuous wave number k. We also show that the Hamilton-Jacobi equation gives a closed function for classical action. These results may be used to calculate the Casimir vacuum energy in Godel univers.

Автор(ы): Мырзакулов Р.*

Объем документа: С. 199-208

МРНТИ: 41.29.25

Ключевые слова: модели скалярного поля*плотность темной энергии*скалярная кривизна Риччи*параметры замедления модели*энтропия*голографическая модель темной энергии*

Реферат: 

Автор(ы): Мырзакулов Р.*

Объем документа: С. 286-292

МРНТИ: 41.29.25

Ключевые слова: голографические сверхпроводники*р-волновые сверхпроводники*параметры сцепления*критическая температура*

Реферат: We study the (3+1)-dimensional p-wave holographic superconductors with Weyl corrections both numerically and analytically. We describe numerically the behavior of the critical temperature Tc with respect to charge density in a limited range of Weyl coupling parameter and we find in general that the condensation becomes harder with the increase of the parameter. In the strong-coupling limit of Yang-Mills theory, we show that the minimum value of Tc obtained from the analytical approach is in good agreement with the numerical results, and finally show how we got remarkably a similar result for the critical exponent of the chemical potential and the order parameter Jx with the numerical curves of the superconductors.

Автор(ы): Мырзакулов Р.*

Объем документа: 

МРНТИ: 41.29.17

Ключевые слова: модели космологии*космическая темная жидкость*особенности разрыва темной жидкости*квинтэссенция*

Реферат: A variety of conditions are considered under which the cosmic dark fluid may be able to develop a future Big Rip or Little Rip singularity. Both one-component and two-component models are considered. In the latter case we present a way in which the fluid can be decomposed into two components, one nonturbulent (ideal) and one turbulent part, obeying two different equations of state. For the nonturbulent part, the thermodynamical parameter, commonly called w, is assumed to be less than -1 throughout. For the turbulent part, it turns out that it is sufficient that wturb lies in the quintessence region in order to lead to a singularity. Both Big Rip and Little Rip behavior for dark energy are found. In the one-component case, we examine how the universe may develop from a viscous era with constant bulk viscosity into a turbulent era, the turbulence in effect protecting the universe from encountering the singularity at all. The equivalent description of the same cosmology in terms of inhomogeneous (imperfect) fluid is also presented.

Автор(ы): Мырзакулов Р.*

Объем документа: С. 2246-2255

МРНТИ: 41.29.17

Ключевые слова: модели темной энергии*параметры замедления модели*космология Калюца - Кляйна*параметры плотности*параметры Хаббла*голографическая темная энергия*модели газа Чаплыгина*

Реферат: In this work, we have calculated the deceleration parameter, statefinder parameters and EoS parameters for different dark energy models with variable G correction in homogeneous, isotropic and non-flat universe for Kaluza-Klein Cosmology. The statefinder parameters have been obtained in terms of some observable parameters like dimensionless density parameter, EoS parameter and Hubble parameter for holographic dark energy, new agegraphic dark energy and generalized Chaplygin gas models.