scholarly journals LRS Bianchi type-I models with a time-dependent cosmological “constant”

1999 ◽  
Vol 60 (6) ◽  
Author(s):  
R. G. Vishwakarma ◽  
Abdussattar ◽  
A. Beesham
Keyword(s):  
Cosmological Constant ◽  
Bianchi Type ◽  
Time Dependent ◽  
Type I ◽  
Bianchi Type I

Cosmological constant in the Bianchi type-I-modified Brans-Dicke cosmology

Pramana ◽  
2003 ◽  
Vol 60 (1) ◽  
pp. 21-27 ◽  
Author(s):  
A. K. Azad ◽  
J. N. Islam
Keyword(s):  
Cosmological Constant ◽  
Bianchi Type ◽  
Type I ◽  
Bianchi Type I

scholarly journals Time-Dependent Toroidal Compactification Proposals and the Bianchi Type I Model: Classical and Quantum Solutions

2016 ◽  
Vol 2016 ◽  
pp. 1-12 ◽  
Author(s):  
L. Toledo Sesma ◽  
J. Socorro ◽  
O. Loaiza
Keyword(s):  
Bianchi Type ◽  
Time Dependent ◽  
Type I ◽  
Dilaton Field ◽  
Dimensional Model ◽  
Dimensional Theory ◽  
Standard Quantum ◽  
Bianchi Type I ◽  
Real Scalar ◽  
The Universe

We construct an effective four-dimensional model by compactifying a ten-dimensional theory of gravity coupled with a real scalar dilaton field on a time-dependent torus. This approach is applied to anisotropic cosmological Bianchi type I model for which we study the classical coupling of the anisotropic scale factors with the two real scalar moduli produced by the compactification process. Under this approach, we present an isotropization mechanism for the Bianchi I cosmological model through the analysis of the ratio between the anisotropic parameters and the volume of the Universe which in general keeps constant or runs into zero for late times. We also find that the presence of extra dimensions in this model can accelerate the isotropization process depending on the momenta moduli values. Finally, we present some solutions to the corresponding Wheeler-DeWitt (WDW) equation in the context of standard quantum cosmology.

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.

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