Bianchi type I cosmological model with perfect fluid and string in f(T) theory of gravitation

2020 ◽  
Vol 29 (08) ◽  
pp. 2050054
Author(s):  
V. R. Chirde ◽  
S. P. Hatkar ◽  
S. D. Katore
Keyword(s):  
Dark Energy ◽  
Perfect Fluid ◽  
Bianchi Type ◽  
Type I ◽  
Field Equations ◽  
Bianchi Type I ◽  
Functional Forms ◽  
Theory Of Gravitation ◽  
Shear Scalar ◽  
The Universe

We have studied LRS Bianchi type I cosmological models with barotropic perfect fluid and cosmic string in the framework of [Formula: see text] theory of gravitation. We have assumed that expansion of the model is proportional to the shear scalar. Hybrid law of expansion is also used to solve the field equations. Three different functional forms of the function [Formula: see text] such as [Formula: see text] [Formula: see text] and [Formula: see text] are chosen for investigation. It is observed that the universe is dominated by quintessence type dark energy. The universe is accelerating, expanding and anisotropic.

LRS Bianchi type I magnetized cosmological model with perfect fluid and with quintessence, Chaplygin gas dark energy in bimetric theory of gravitation

2016 ◽  
Vol 26 (07) ◽  
pp. 1750061 ◽  
Author(s):  
M. S. Borkar ◽  
P. V. Gayakwad
Keyword(s):  
Magnetic Field ◽  
Dark Energy ◽  
Perfect Fluid ◽  
Bianchi Type ◽  
Chaplygin Gas ◽  
Bimetric Theory ◽  
Type I ◽  
Bianchi Type I ◽  
Theory Of Gravitation ◽  
Quintessence Model

We studied the LRS Bianchi type I cosmological models with perfect fluid, quintessence and standard Chaplygin gas dark energy in the presence as well as in the absence of magnetic field [Formula: see text], in bimetric theory of gravitation. It is realized that the magnetic field controlled the whole behavior of the models. In the absence of magnetic field, these models exists and the model never exists in the presence of magnetic field. The geometry of quintessence model for [Formula: see text] and standard Chaplygin gas model coincide and their physical behavior are same in the absence of magnetic field. Some geometrical and physical properties of each of the model are explored. The model have also been studied in regard with the singularities and it is pointed out that the model is singular in the presence of magnetic field and nonsingular in the absence of magnetic field.

scholarly journals Bianchi Type-I Dark Energy Cosmology with Power-Law Relation in Brans-Dicke Theory of Gravitation

2018 ◽  
Vol 2018 ◽  
pp. 1-11 ◽  
Author(s):  
S. D. Katore ◽  
D. V. Kapse
Keyword(s):  
Dark Matter ◽  
Dark Energy ◽  
Power Law ◽  
Bianchi Type ◽  
Type I ◽  
Field Equations ◽  
Coincidence Problem ◽  
Bianchi Type I ◽  
Interacting Dark Energy ◽  
Theory Of Gravitation

We have studied the interacting and non-interacting dark energy and dark matter in the spatially homogenous and anisotropic Bianchi type-I model in the Brans-Dicke theory of gravitation. The field equations have been solved (i) by using power-law relation and (ii) by assuming scale factor in terms of redshift. Here we have considered two cases of an interacting and non-interacting dark energy scenario and obtained general results. It has been found that for suitable choice of interaction between dark energy and dark matter we can avoid the coincidence problem which appears in the ΛCDM model. Some physical aspects and stability of the models are discussed in detail. The statefinder diagnostic pair, i.e., {r,s}, is adopted to differentiate our dark energy models.

The Mimetic Matter in LRS Bianchi Type-I Model

2021 ◽  
Author(s):  
Ertan Gudekli ◽  
E. Demir
Keyword(s):  
Bianchi Type ◽  
State Parameter ◽  
Relativity Theory ◽  
Type I ◽  
Field Equations ◽  
Bianchi Type I ◽  
Rotationally Symmetric ◽  
Bianchi Type I Universe ◽  
Expansion Of The Universe ◽  
The Universe

This paper deals with the Locally rotationally symmetric (LRS) Bianchi type-I universe model in Mimetic Gravity Theory assuming it an extended form of General Relativity Theory. It was proclaimed as a conformal transformation of the Einstein-Hilbert action from Einstein frame to Jordon frame. At the outset, we have proposed a potential function on account of clarifying the expansion of our universe by considering the general solutions of the field equations that originate from the action of the theory including the Lagrange multipliers. Lastly, after having been achieved the general equation of the state parameter ω, we discussed whether the result corresponds to some fluids illuminating the expansion of the Universe or not.

Bianchi type VI0 generalized ghost pilgrim dark energy model in Brans–Dicke theory of gravitation

2016 ◽  
Vol 94 (10) ◽  
pp. 1040-1044 ◽  
Author(s):  
V.U.M. Rao ◽  
U.Y. Divya Prasanthi
Keyword(s):  
Dark Energy ◽  
Bianchi Type ◽  
Field Equations ◽  
Pilgrim Dark Energy ◽  
Geometrical Properties ◽  
Scalar Expansion ◽  
Theory Of Gravitation ◽  
Shear Scalar ◽  
Bianchi Type Vi0 ◽  
Average Scale Factor

In this paper, we solve Brans–Dicke (BD) theory (Phys. Rev. D, 24, 925) field equations for anisotropic Bianchi type VI0 space–time and discuss evolution of the expanding Universe. Here, we consider pressureless fluid and isotropic generalized ghost pilgrim dark energy as the source of matter and dark energy, respectively. To get the determinate solution of the field equations we have used (i) scalar expansion proportional to the shear scalar and (ii) scalar field (in BD theory) proportional to average scale factor of the model. Some physical and geometrical properties of the model are also discussed.

scholarly journals Bianchi Type I Cosmological Models with Expansion Driven by Particle Creation

2018 ◽  
Author(s):  
Kalyani Desikan
Keyword(s):  
Bianchi Type ◽  
Energy Momentum Tensor ◽  
Particle Creation ◽  
Momentum Tensor ◽  
Conservation Equation ◽  
Type I ◽  
Field Equations ◽  
Bianchi Type I ◽  
Energy Conservation Equation ◽  
The Universe

A study of Bianchi Type I cosmological model is undertaken in the framework of creation of particles. To accommodate the creation of new particles, the universe is regarded as an Open thermodynamical system. The energy conservation equation is modified with the incorporation of a creation pressure in the energy momentum tensor. Exact solutions of the field equations are obtained (i) for a particular choice of the particle creation function and (ii) by considering the deceleration parameter to be constant. In the first model the behavior of the solution at late times is investigated. The physical aspects of the model have also been discussed. In the case of the second model we have restricted our analysis to the power law behaviour for the average scale factor. This leads to a particular form for the particle creation function. The behavior of the solution is investigated and the physical aspects of the model have also been discussed for the matter dominated era.

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