Locally rotationally symmetric Bianchi type I cosmology in f(R) gravity

2015 ◽  
Vol 93 (1) ◽  
pp. 37-42 ◽  
Author(s):  
M. Farasat Shamir ◽  
Zahid Raza
Keyword(s):  
Bianchi Type ◽  
Type I ◽  
Field Equations ◽  
Three Solutions ◽  
Bianchi Type I ◽  
Locally Rotationally Symmetric ◽  
Expansion Scalar ◽  
Rotationally Symmetric ◽  
Bianchi Type I Universe ◽  
Killing Symmetries

This manuscript is devoted to investigating a Bianchi type I universe in the context of f(R) gravity. For this purpose, we explore the exact solutions of locally rotationally symmetric Bianchi type I space–time in the metric version of f(R) gravity. The modified field equations are solved by assuming the expansion scalar θ to be proportional to the shear scalar σ, which gives A = Bn, where A and B are the metric coefficients, and n is an arbitrary constant. In particular, three solutions have been found and corresponding Killing symmetries are calculated in each case.

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.

Locally rotationally symmetric Bianchi type-I string cosmological models in f(R) theory of gravity

2018 ◽  
Vol 15 (09) ◽  
pp. 1850156 ◽  
Author(s):  
Y. Aditya ◽  
D. R. K. Reddy
Keyword(s):  
Bianchi Type ◽  
Scalar Fields ◽  
Cosmological Models ◽  
Cosmic Acceleration ◽  
Type I ◽  
Field Equations ◽  
Bianchi Type I ◽  
Locally Rotationally Symmetric ◽  
Rotationally Symmetric ◽  
Theory Of Gravity

This study deals with spatially homogeneous and anisotropic locally rotationally symmetric (LRS) Bianchi type-I universe with cosmic string source in the framework of [Formula: see text] theory of gravity [S. Capozziello, S. Carloni and A. Troisi, Quintessence without scalar fields, Recent Res. Dev. Astron. Astrophys. 1 (2003), 625; S. Nojiri and S. D. Odintsov, Modified gravity with negative and positive powers of curvature: Unification of inflation and cosmic acceleration, Phys. Rev. D 68 (2003) 123512]. Solving the field equations using (i) relation between metric potentials, (ii) power law relation between [Formula: see text] and average scale factor [Formula: see text] and (iii) equations of state for string models we have presented Takabayasi [T. Takabayasi, Quantum Mechanics Determinism, Causality, and Particles (Springer, Berlin, 1976)], Nambu [P. S. Letelier, String cosmologies, Phys. Rev. D 28 (1983) 2414–2419] and Reddy [D. R. K. Reddy, A string cosmological model in a scalar–Tensor theory of gravitation, Astrophys. Space Sci. 286 (2003) 359–363] string cosmological models. The dynamical parameters of our models are determined and their physical behavior is discussed. The most interesting result about the models is that the anisotropic effects are wiped out at late times.

On symmetries and conservation laws of some spacetimes in f(R, T) gravity

2019 ◽  
Vol 34 (36) ◽  
pp. 1975003
Author(s):  
Ashfaque H. Bokhari ◽  
A. H. Kara ◽  
B. Gadjagboui
Keyword(s):  
Conservation Laws ◽  
Detailed Analysis ◽  
Bianchi Type ◽  
Type I ◽  
Noether’S Theorem ◽  
Bianchi Type I ◽  
Plane Symmetric ◽  
Locally Rotationally Symmetric ◽  
Rotationally Symmetric ◽  
Variational Symmetries

We undertake a detailed analysis of the symmetry structures of the plane symmetric and the locally rotationally symmetric (LRS) Bianchi type I spacetimes in the [Formula: see text] gravity. In particular, we construct all the variational symmetries associated with its Lagrangian and, in some cases, construct the associated conservation laws using Noether’s theorem. Giving a comparison between isometries and variational symmetries, we give symmetry structures of some well-known spacetimes.

VISUALIZING MINISUPERSPACE DYNAMICS

1993 ◽  
Vol 08 (30) ◽  
pp. 2815-2825 ◽  
Author(s):  
KJELL ROSQUIST ◽  
CLAES UGGLA
Keyword(s):  
Bianchi Type ◽  
Type I ◽  
Bianchi Type I ◽  
Locally Rotationally Symmetric ◽  
Rotationally Symmetric

We show that one can find a useful compactified representation of minisuperspace dynamics using conformal diagrams and how global and asymptotic qualitative features of the dynamics can be inferred from. the diagrams. To provide explicit examples this is done for the locally rotationally symmetric Bianchi type I and IX models.

scholarly journals Locally Rotationally Symmetric Bianchi Type-I Cosmological Model in f(R,T) Gravity

2019 ◽  
Vol 1344 ◽  
pp. 012004
Author(s):  
M.Vijaya Santhi ◽  
Daba Meshesha Gusu ◽  
V.U.M. Rao ◽  
G. Suryanarayana
Keyword(s):  
Cosmological Model ◽  
Bianchi Type ◽  
Type I ◽  
Bianchi Type I ◽  
Locally Rotationally Symmetric ◽  
Rotationally Symmetric

scholarly journals Bianchi Type-I Universe with Cosmological Constant and Quadratic Equation of State inf(R,T)Modified Gravity

2015 ◽  
Vol 2015 ◽  
pp. 1-12 ◽  
Author(s):  
G. P. Singh ◽  
Binaya K. Bishi
Keyword(s):  
Equation Of State ◽  
Cosmological Constant ◽  
Modified Gravity ◽  
Bianchi Type ◽  
Quadratic Equation ◽  
Type I ◽  
Field Equations ◽  
Bianchi Type I ◽  
Bianchi Type I Universe ◽  
Quadratic Equation Of State

This paper deals with the study of Bianchi type-I universe in the context off(R,T)gravity. Einstein’s field equations inf(R,T)gravity have been solved in the presence of cosmological constantΛand quadratic equation of state (EoS)p=αρ2-ρ, whereα≠0is a constant. Here, we have discussed two classes off(R,T)gravity; that is,f(R,T)=R+2f(T)andf(R,T)=f1(R)+f2(T). A set of models has been taken into consideration based on the plausible relation. Also, we have studied some physical and kinematical properties of the models.

scholarly journals LRS Bianchi type-I Universe with anisotropic dark energy and special form of deceleration parameter in f (R, T) gravity

2018 ◽  
Vol 6 (1) ◽  
pp. 1
Author(s):  
Rajesh Wankhade ◽  
A.S. Bansod
Keyword(s):  
Deceleration Parameter ◽  
Special Form ◽  
Bianchi Type ◽  
Momentum Tensor ◽  
Physical Aspect ◽  
Type I ◽  
Field Equations ◽  
Bianchi Type I ◽  
Anisotropic Dark Energy ◽  
Bianchi Type I Universe

In this paper, LRS Bianchi type-I space-time is considered in the presence of perfect fluid source in the frame work of  gravity (Harko et al. in Phys.Rev. D 84:024020, 2011) where is an arbitrary function of Ricci scalar  and trace of the energy momentum tensor . The Einstein’s field equations have been solved by taking into account the special form of deceleration parameter (Singha A., Debnath U.: Int.J. Theor. Phys.48, 2009). We observe that in f (R, T) gravity, an extra acceleration is always present due to coupling between matter and geometry. The geometrical and physical aspect of the model is also studied.

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