Higher Dimensional Bianchi Type-I Cosmological Models With Massive String in General Relativity

Singh, Kangujam Priyokumar; Baro, Jiten; Meitei, Asem Jotin

doi:10.3389/fspas.2021.777554

Cited by 4 publications

(1 citation statement)

References 45 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Some authors have demonstrated in their research that the four-dimensional spacetimes expand while the fifth dimension contracts or remains constant. Recently [13][14][15], several authors have studied higher dimensions using different cosmological Models.…”

Section: Introductionmentioning

confidence: 99%

Anisotropic L. R. S. Bianchi type-V Cosmological Models with Bulk Viscous String within the Framework of Saez-Ballester Theory in Five-Dimensional Spacetime

Daimary,

Baruah

2024

J. Sci. Res.

View full text Add to dashboard Cite

When the source for the energy-momentum tensor is a bulk viscous fluid containing one-dimensional cosmic strings, a spatially homogeneous and anisotropic Bianchi type-V cosmological model is considered in this paper in a scalar-tensor theory of gravitation proposed by Saez-Ballester, we derive a determinate solution utilizing the plausible physical conditions: (i) the scalar of spacetime expansion is proportional to the shear scalar; (ii) the baratropic equation of state for pressure and density; and (iii) the bulk viscous pressure is related to the energy density. The model's physical and kinematic features are also discussed.

show abstract

Section: Introductionmentioning

confidence: 99%

Anisotropic L. R. S. Bianchi type-V Cosmological Models with Bulk Viscous String within the Framework of Saez-Ballester Theory in Five-Dimensional Spacetime

Daimary,

Baruah

2024

J. Sci. Res.

View full text Add to dashboard Cite

show abstract

String cosmological scenario in periodic time-varying deceleration parameter in Lyra geometry

2023

View full text Add to dashboard Cite

In this paper, we have studied the bulk viscous fluid connected with string cosmological model in a higher dimensional (five dimensions) Bianchi type-III space–time in the framework of Lyra’s manifold. To get the deterministic solution of the field equations, we assume two physically appropriate conditions: ( i) θ in the model parameter that is proportional to the eigen value of [Formula: see text] of the shear tensor [Formula: see text] and ( ii) the periodic time-varying deceleration parameter q specified as q = mcos ( kt) − 1, where m, k > 0. In this paper, we have studied the periodic time-varying behaviour of a few quantities, such as the deceleration parameter q, the energy density ρ, the proper pressure p, the string tension density λ, the total pressure [Formula: see text], the energy density for particle ρp, and the displacement vector β( t), and we have discussed the physical significance of these quantities. It has been found that in the early stages of the universe’s evolution, string prevails over particles, whereas the universe is dominated by massive string at late time. It is also noted that the string phase of the cosmos does not vanish in the model since particle density is constantly positive throughout the universe’s history. In normal gauge treatment, β( t) acts like cosmological constant (Λ), and the solutions are compatible with observations. For the stability analysis, we have investigated the nature of various energy conditions (ECs). The positive behaviour of DEC indicates the model’s validation; on the other hand, SEC and WEC are violating, indicating the universe’s accelerated expansion.

show abstract

Analysis of heat flow in the post-quasi-static approximation for gravitational collapse in five dimension

2023

View full text Add to dashboard Cite

In this work, a generalized framework of the post-quasistatic approximation in higher dimensional non-comoving coordinates is presented. We study the evolution of adiabatically radiating and dissipative fluid configuration in higher dimensional post-quasi-static approximation. An iterative method for describing self-gravitating spheres is developed for this purpose. Dissipation is described by free-streaming radiation and heat flux. We match the higher dimensional interior solution, in non-comoving coordinates, with the corresponding Vaidya exterior solution. The generalized form of post-quasistatic approximation leads to a system of higher dimensional surface equations. The surface equations are of significant importance in the understanding of the physical phenomenon like luminosity, Doppler shift and red-shift at the boundary surface of gravitating sources.

show abstract

Higher Dimensional Bianchi Type-I Cosmological Models With Massive String in General Relativity

Cited by 4 publications

References 45 publications

Anisotropic L. R. S. Bianchi type-V Cosmological Models with Bulk Viscous String within the Framework of Saez-Ballester Theory in Five-Dimensional Spacetime

Anisotropic L. R. S. Bianchi type-V Cosmological Models with Bulk Viscous String within the Framework of Saez-Ballester Theory in Five-Dimensional Spacetime

String cosmological scenario in periodic time-varying deceleration parameter in Lyra geometry

Analysis of heat flow in the post-quasi-static approximation for gravitational collapse in five dimension

Contact Info

Product

Resources

About