arXiv subjects

D. P. Tadas

Publications and source records attributed to D. P. Tadas.

5 recordsLinked to original sources

arXiv2024

Domain Wall and Holographic Dark Energy in $f(Q)$ Theory of Gravity

In the present research article, we have studied the flat FRW space time with domain wall and holographic dark energy in the context of $f(Q)$ theory of gravity. The exact solutions of the field equations are obtained using two different forms of varying deceleration parameters: (i) $q=-b(t)-1$ and (ii) $q=-lt+m-1$. It is observed that the universe is accelerating and expanding. Furthermore, we have also discussed some physical parameters of the investigated model.

gr-qc↗

arXiv2023

An Oscillating Holographic Dark Energy in $f(R)$ Gravity

In this article, we investigated a Locally Rotationally Symmetric (LRS) Bianchi-II cosmological model with matter and Holographic Dark Energy (HDE) in the context of $f(R)$ theory of gravity. In order to find exact solutions to the field equations, we assumed that the Shear scalar $(σ)$ is proportional to Expansion scalar $(θ)$. For HDE, it is observed that the Equation of state (EoS) parameter $ ω_Λ $ has an oscillating nature and lies in $[-0.778,\, 1.016].$ Also, we have studied the validity of energy conditions and shows that Null Energy Condition (NEC) is violated near the bouncing points. Moreover, we analysed the physical and geometrical aspects of the investigated model. Keywords: Holographic dark energy, LRS Bianchi-II, $f(R)$ gravity.

gr-qc↗

arXiv2023

Accelerating Kaluza-Klein Universe in Modified Theory of Gravitation

The purpose of this paper is to study the Kaluza-Klein universe in the context of the $f(R,T)$ gravity theory using magnetized strange quark matter (MSQM). To obtain exact solutions of field equations, we assume two types of volumetric expansion: power law and exponential law volumetric expansions. The violation of energy conditions has been studied. The physical and geometrical properties of the examined model have also been investigated thoroughly. Keywords: Kaluza-Klein metric, Magnetized Strange Quark Matter, Power and Exponential law, $f(R,T)$ gravity.

gr-qc↗

arXiv2023

Domain Wall Bianchi Type $VI_0$ Universe in $f(R,T)$ Gravity

We consider the Bianchi type-$VI_0$ space time with domain walls in the framework of the modified $f (R, T)$ theory of gravitation. To solve the field equations, we assume that the shear scalar $(\sigma)$ is proportional to the expansion scalar $(\theta)$. We also consider the parametrization of the equation of the state parameter of barotropic fluid and discuss the effect on domain walls. It has been observed that the domain wall may behave like dark energy. Some physical parameters are also discussed in detail.

gr-qc↗

arXiv2023

Non-interacting String and Holographic Dark Energy Cosmological Models in f(R) Theory of Gravitation

In this paper, a new class of string and holographic dark energy (HDE) cosmological model in the context of the $f(R)$ theory of gravity using the Kasner metric is considered. The exact solution of the field equations is obtained using the relation between the average scale factor and the scalar function $f(R)$. It is observed that the universe is accelerating and expanding. The string phase of the universe is present at an early stage of the evolution of the universe. The universe is dominated by quintessence type HDE at present. The effect of the curvature function $f(R)$ is also observed on dynamical parameters.

gr-qc↗