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.

Anisotropic models with generalized hybrid expansion in Brans–Dicke theory of gravity

2021 ◽  
pp. 2150141
Author(s):  
S. Surendra Singh ◽  
Yohenba Soibam
Keyword(s):  
Dark Matter ◽  
Dark Energy ◽  
Power Law ◽  
Bianchi Type ◽  
Scale Factor ◽  
Late Time ◽  
Type I ◽  
Coincidence Problem ◽  
Bianchi Type I ◽  
Average Scale Factor

The hybrid expansion law (HEL) for average scale factor that yields power-law and exponential-law cosmologies is considered in spatially homogenous and anisotropic Bianchi type-I model in the context of Brans–Dicke (BD) Theory of gravitation. The solutions of the field equations have been calculated by assuming the power-law expression between the average scale factor [Formula: see text] and scalar field ([Formula: see text]). We studied both interacting and non-interacting forms of dark energy and dark matter and obtained respective solutions. The energy density [Formula: see text] decreases with time while energy densities [Formula: see text] increases with time. In both the cases, the physical acceptability and stability of the models are also studied. The coincidence problem in [Formula: see text]CDM model can be ruled out with proper choice of coupling between dark matter (DM) and dark energy (DE). We also discussed the physical behaviors of the derived models with the current observations applied to late-time acceleration and beginning of the universe. In this model, it is observed that our HEL Bianchi type I universe is highly anisotropic in the beginning of universe and becomes isotropic and overlaps with flat [Formula: see text]CDM model at late times.

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.

A new class of holographic dark energy models in LRS Bianchi Type-I

2021 ◽  
Author(s):  
Anirudh Pradhan ◽  
Vinod Kumar Bhardwaj ◽  
Archana Dixit ◽  
Syamala Krishnannair
Keyword(s):  
Dark Energy ◽  
Bianchi Type ◽  
Holographic Dark Energy ◽  
Cosmological Solution ◽  
Type I ◽  
Field Equations ◽  
Eos Parameter ◽  
Bianchi Type I ◽  
New Class ◽  
Energy Models

In this paper, we examine the LRS Bianchi-type-I cosmological model with holographic dark energy. The exact solutions to the corresponding field equations are obtained by using the generalized hybrid expansion law (HEL). The EoS parameter [Formula: see text] for DE is found to be time-dependent and redshift-dependent and its exiting range for derived model is agreeing well with the current observations. Here, we likewise apply two mathematical diagnostics, the statefinders ([Formula: see text]) and [Formula: see text] plan to segregate HDE model from the [Formula: see text]CDM model. Here, the [Formula: see text] diagnostic trajectories are good tools to classify the dynamical DE model. We found that our model lies in both thawing region and freezing region. We also construct the potential as well as dynamics of the quintessence and tachyon scalar field. Some physical and geometric properties of this model along with the physical acceptability of cosmological solution have been discussed in detail.

scholarly journals LRS Bianchi Type-I Inflationary String Cosmological Model in Brans-Dicke Theory of Gravitation

2014 ◽  
Vol 2014 ◽  
pp. 1-5 ◽  
Author(s):  
R. Venkateswarlu ◽  
J. Satish
Keyword(s):  
Scalar Field ◽  
Cosmological Model ◽  
Power Law ◽  
Bianchi Type ◽  
Type I ◽  
Physical Behavior ◽  
Bianchi Type I ◽  
Expansion Scalar ◽  
Theory Of Gravitation ◽  
Shear Scalar

We investigate locally rotational symmetric (LRS) Bianchi type I space time coupled with scalar field. String cosmological models generated by a cloud of strings with particles attached to them are studied in the Brans-Dicke theory. We assume that the expansion scalar is proportional to the shear scalar and also power law ansatz for scalar field. The physical behavior of the resulting model is discussed through different parameters.

LRS Bianchi Type-I Dark Energy Cosmological Model in Brans-Dicke Theory of Gravitation

2012 ◽  
Vol 51 (10) ◽  
pp. 3303-3310 ◽  
Author(s):  
V. U. M. Rao ◽  
M. Vijaya Santhi ◽  
T. Vinutha ◽  
G. Sree Devi Kumari
Keyword(s):  
Dark Energy ◽  
Cosmological Model ◽  
Bianchi Type ◽  
Type I ◽  
Bianchi Type I ◽  
Theory Of Gravitation
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