Viscous string anisotropic cosmological model in scalar–tensor theory

Vinutha, T.; Rao, V. U. M.; Bekele, G.; Kavya, K. Sri

doi:10.1007/s12648-020-01850-z

“…Reddy et al [48] have investigated Kaluza-Klein bulk viscous string model of the universe in Saez-Ballester theory of gravity, whereas, Naidu et al [49] have investigated same model in Brans-Dicke gravity. Recently, Vinutha et al [50] have investigated Kantowski-Sachs viscous string cosmological model in Saez-Ballester theory of gravity and reported that the model shows phantom behavior. Now, for a bulk viscous fluid containing cosmic strings, the stress-energy tensor T µν is given by…”

Section: Basic Equationsmentioning

confidence: 99%

Untitled

2023

Bulg.J.Phys.

0

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The present communication deals with the tilted Bianchi type-VI0 bulk viscous string cosmological models in Sáez-Ballester theory of gravitation.To obtain an exact solution of the field equations, we consider three feasible physical relations, viz., expansion scalar θ as proportional to one of the components of the shear scalar σ, bilinear varying deceleration parameter (BVDP) and bulk viscosity coefficient ξ as a simple power function of the energy density ρ. We also discuss the behaviour of physical and geometrical parameters of the obtained models. For the stability of the solution, the nature of energy conditions is explored graphically. The findings of the models are in good agreement with the observational data.

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“…Reddy et al [48] have investigated Kaluza-Klein bulk viscous string model of the universe in Saez-Ballester theory of gravity, whereas, Naidu et al [49] have investigated same model in Brans-Dicke gravity. Recently, Vinutha et al [50] have investigated Kantowski-Sachs viscous string cosmological model in Saez-Ballester theory of gravity and reported that the model shows phantom behavior. Now, for a bulk viscous fluid containing cosmic strings, the stress-energy tensor T µν is given by…”

Section: Basic Equationsmentioning

confidence: 99%

Certain Investigations on Bulk Viscous String Models of the Universe with BVDP

2023

Bulg.J.Phys.

1

0

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The present communication deals with the tilted Bianchi type-VI0 bulk viscous string cosmological models in Sáez-Ballester theory of gravitation.To obtain an exact solution of the field equations, we consider three feasible physical relations, viz., expansion scalar θ as proportional to one of the components of the shear scalar σ, bilinear varying deceleration parameter (BVDP) and bulk viscosity coefficient ξ as a simple power function of the energy density ρ. We also discuss the behaviour of physical and geometrical parameters of the obtained models. For the stability of the solution, the nature of energy conditions is explored graphically. The findings of the models are in good agreement with the observational data.

show abstract