The Bianchi type-IX cosmological models with binary mixture of perfect fluid (PF) and anisotropic... more The Bianchi type-IX cosmological models with binary mixture of perfect fluid (PF) and anisotropic dark energy (DE) have been studied. In order to obtain a unique solution, it is assumed that the energy conservation equation of the PF and DE vanishes separately together with a special law for the mean Hubble parameter which yields a constant value of the deceleration parameter.To have a general description of an anisotropic DE component in terms of its equation of state (EoS)) (de , two skewness parameters , have been introduced. It has been found out that the anisotropic distribution of DE leads to the present accelerated expansion of the universe. The geometrical and physical parameters of the model are studied. The analysis of the model reveals that the present acceleration, isotropy of the universe turns out to be natural consequences of DE.
The Bianchi type-IX cosmological model with variable ω has been studied in the scalar tensor theo... more The Bianchi type-IX cosmological model with variable ω has been studied in the scalar tensor theory of gravitation proposed by Saez and Ballester [Phys. Lett. A 113: 467, 1985] in the presence and absence of magnetic field of energy density ρb. A special law of variation of Hubble’s parameter proposed by Berman [Nuovo Cimento 74 B, 182, 1983] has been used to solve the field equations. The physical and kinematical properties of the model are also discussed.
We have studied Kaluza-Klein universe in the presence of cosmic strings as a source in a scalar t... more We have studied Kaluza-Klein universe in the presence of cosmic strings as a source in a scalar tensor theory of gravitation proposed by Brans and Dicke (1961) which is the extension of five dimensional Kaluza-Klein string cosmological models investigated by Reddy et al., (2007). Some physical properties of the model are also discussed.
International Journal of Theoretical and Mathematical Physics, 2014
A Bianchi type-IX bulk viscous string cosmological model has been investigated in the frame work ... more A Bianchi type-IX bulk viscous string cosmological model has been investigated in the frame work of ) , ( T R f gravity proposed by Harko et al. (Phys. Rev. D 84:024020, 2011). The source for energy momentum tensor is bulk viscous fluid containing one dimensional cosmic strings. The field equations have been solved by applying a special form of deceleration parameter proposed by Singha and Debnath (IJTP 48:351, 2009). A barotropic equation of state for the pressure and energy density is assumed to get a determinate solution of the field equations. Also the bulk viscous pressure is assumed to be proportional to energy density. The physical and geometrical properties of the models are also discussed.
N-dimensional FRW cosmological model in Hoyle-Narlikar's creation field theory of gravitation... more N-dimensional FRW cosmological model in Hoyle-Narlikar's creation field theory of gravitation has been studied, when the universe is filled with dust distribution. To get the deterministic solution, the cosmological constant ) (t is considered as a time dependent function of cosmic time t i.e. 2 1 R , where R is a scale factor. The physical aspects of the model are also studied.
The exact solutions of the Einstein field equations for dark energy (DE) in Bianchi type-IX metri... more The exact solutions of the Einstein field equations for dark energy (DE) in Bianchi type-IX metric under the assumption on anisotropy of the fluid are obtained for exponential volumetric expansion within the frame work of Lyra manifold for uniform and time varying displacement field. The isotropy of the fluid and space is examined.
Bianchi type-IX cosmological model with variable equation of state (EoS) parameter have been inve... more Bianchi type-IX cosmological model with variable equation of state (EoS) parameter have been investigated in general scalar-tensor theory of gravitation proposed by Sen and Dunn (J. Math. Phys. 12:578, 1971) when universe is filled with Dark Energy. The field equations have been solved by considering the scale factors in two different forms (i) ()ltretR1= , where r and l are positive constants and (ii) ()()ntR1sinhξ=, where ξ and n are positive constants, which render time dependent deceleration parameter. The physical and geometrical properties of the models are also discussed.
International Journal of Innovative Research in Science, Engineering and Technology, 2014
A Bianchi type-IX cosmological model has been investigated in the presence of perfect fluid with ... more A Bianchi type-IX cosmological model has been investigated in the presence of perfect fluid with disordered radiation in Barbers (Gen. Relat. Gravit.14, 117, 1982) second self-creation theory of gravitation. The field equations have been solved by applying special law of variation for generalized Hubble’s parameter given by Bermann (NuovoCimento 74, 182, 1983). Some physical properties of the models are also discussed.
A Bianchi type-IX dark energy cosmological model with variable equation of state (EoS) parameter ... more A Bianchi type-IX dark energy cosmological model with variable equation of state (EoS) parameter is obtained in Barber’s second Self-Creation theory of gravitation. The field equations have been solved by applying variation law for generalized Hubble’s parameter given by Bermann. Some physical properties of the models are also discussed.
Bianchi type-IX cosmological model with variable equation of state (EoS) parameter have been inve... more Bianchi type-IX cosmological model with variable equation of state (EoS) parameter have been investigated in general scalar-tensor theory of gravitation proposed by Sen and Dunn (J. Math. Phys. 12:578, 1971) when universe is filled with Dark Energy. The field equations have been solved by considering the scale factors in two different forms (i) ( )l t r e t R 1 = , where r and l are positive constants and (ii) ( ) ( )n t R 1 sinh ξ = , where ξ and n are positive constants, which render time dependent deceleration parameter. The physical and geometrical properties of the models are also discussed.
The Bianchi type-IX cosmological models with binary mixture of perfect fluid (PF) and anisotropic... more The Bianchi type-IX cosmological models with binary mixture of perfect fluid (PF) and anisotropic dark energy (DE) have been studied. In order to obtain a unique solution, it is assumed that the energy conservation equation of the PF and DE vanishes separately together with a special law for the mean Hubble parameter which yields a constant value of the deceleration parameter.To have a general description of an anisotropic DE component in terms of its equation of state (EoS)) (de , two skewness parameters , have been introduced. It has been found out that the anisotropic distribution of DE leads to the present accelerated expansion of the universe. The geometrical and physical parameters of the model are studied. The analysis of the model reveals that the present acceleration, isotropy of the universe turns out to be natural consequences of DE.
The Bianchi type-IX cosmological model with variable ω has been studied in the scalar tensor theo... more The Bianchi type-IX cosmological model with variable ω has been studied in the scalar tensor theory of gravitation proposed by Saez and Ballester [Phys. Lett. A 113: 467, 1985] in the presence and absence of magnetic field of energy density ρb. A special law of variation of Hubble’s parameter proposed by Berman [Nuovo Cimento 74 B, 182, 1983] has been used to solve the field equations. The physical and kinematical properties of the model are also discussed.
We have studied Kaluza-Klein universe in the presence of cosmic strings as a source in a scalar t... more We have studied Kaluza-Klein universe in the presence of cosmic strings as a source in a scalar tensor theory of gravitation proposed by Brans and Dicke (1961) which is the extension of five dimensional Kaluza-Klein string cosmological models investigated by Reddy et al., (2007). Some physical properties of the model are also discussed.
International Journal of Theoretical and Mathematical Physics, 2014
A Bianchi type-IX bulk viscous string cosmological model has been investigated in the frame work ... more A Bianchi type-IX bulk viscous string cosmological model has been investigated in the frame work of ) , ( T R f gravity proposed by Harko et al. (Phys. Rev. D 84:024020, 2011). The source for energy momentum tensor is bulk viscous fluid containing one dimensional cosmic strings. The field equations have been solved by applying a special form of deceleration parameter proposed by Singha and Debnath (IJTP 48:351, 2009). A barotropic equation of state for the pressure and energy density is assumed to get a determinate solution of the field equations. Also the bulk viscous pressure is assumed to be proportional to energy density. The physical and geometrical properties of the models are also discussed.
N-dimensional FRW cosmological model in Hoyle-Narlikar's creation field theory of gravitation... more N-dimensional FRW cosmological model in Hoyle-Narlikar's creation field theory of gravitation has been studied, when the universe is filled with dust distribution. To get the deterministic solution, the cosmological constant ) (t is considered as a time dependent function of cosmic time t i.e. 2 1 R , where R is a scale factor. The physical aspects of the model are also studied.
The exact solutions of the Einstein field equations for dark energy (DE) in Bianchi type-IX metri... more The exact solutions of the Einstein field equations for dark energy (DE) in Bianchi type-IX metric under the assumption on anisotropy of the fluid are obtained for exponential volumetric expansion within the frame work of Lyra manifold for uniform and time varying displacement field. The isotropy of the fluid and space is examined.
Bianchi type-IX cosmological model with variable equation of state (EoS) parameter have been inve... more Bianchi type-IX cosmological model with variable equation of state (EoS) parameter have been investigated in general scalar-tensor theory of gravitation proposed by Sen and Dunn (J. Math. Phys. 12:578, 1971) when universe is filled with Dark Energy. The field equations have been solved by considering the scale factors in two different forms (i) ()ltretR1= , where r and l are positive constants and (ii) ()()ntR1sinhξ=, where ξ and n are positive constants, which render time dependent deceleration parameter. The physical and geometrical properties of the models are also discussed.
International Journal of Innovative Research in Science, Engineering and Technology, 2014
A Bianchi type-IX cosmological model has been investigated in the presence of perfect fluid with ... more A Bianchi type-IX cosmological model has been investigated in the presence of perfect fluid with disordered radiation in Barbers (Gen. Relat. Gravit.14, 117, 1982) second self-creation theory of gravitation. The field equations have been solved by applying special law of variation for generalized Hubble’s parameter given by Bermann (NuovoCimento 74, 182, 1983). Some physical properties of the models are also discussed.
A Bianchi type-IX dark energy cosmological model with variable equation of state (EoS) parameter ... more A Bianchi type-IX dark energy cosmological model with variable equation of state (EoS) parameter is obtained in Barber’s second Self-Creation theory of gravitation. The field equations have been solved by applying variation law for generalized Hubble’s parameter given by Bermann. Some physical properties of the models are also discussed.
Bianchi type-IX cosmological model with variable equation of state (EoS) parameter have been inve... more Bianchi type-IX cosmological model with variable equation of state (EoS) parameter have been investigated in general scalar-tensor theory of gravitation proposed by Sen and Dunn (J. Math. Phys. 12:578, 1971) when universe is filled with Dark Energy. The field equations have been solved by considering the scale factors in two different forms (i) ( )l t r e t R 1 = , where r and l are positive constants and (ii) ( ) ( )n t R 1 sinh ξ = , where ξ and n are positive constants, which render time dependent deceleration parameter. The physical and geometrical properties of the models are also discussed.
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