The Plane Symmetric Einstein-Dust System with Positive Cosmological Constant (original) (raw)
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2013
In many cases a massive nonlinear scalar field can lead to accelerated expansion in cosmological models. This paper contains mathematical results on this subject for flat Robertson-Walker space-time. Global existence to the coupled Einstein-massive scalar field system which rules the dynamics of a kind of pure matter in the presence of a massive scalar field and cosmological constant is proved, under the assumption that the scalar field ? is a non-decreasing function, in Robertson-Walker1 space-time; asymptotic behaviour are investigated in the case of a cosmological constant bounded from below by a strictly negative constant depending only on the massive scalar field.
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Discussions on a special static spherically symmetric perfect fluid solution of Einstein's equations
2008
In this article, a special static spherically symmetric perfect fluid solution of Einstein's equations is provided. Though pressure and density both diverge at the origin, their ratio remains constant. The solution presented here fails to give positive pressure but nevertheless, it satisfies all energy conditions. In this new spacetime geometry, the metric becomes singular at some finite value of radial coordinate although, by using isotropic coordinates, this singularity could be avoided, as has been shown here. Some characteristics of this solution are also discussed.
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A New Class of Inhomogeneous Cosmological Solutions
1996
Beginning with a special form of the Einstein-Rosen metric, we find new cosmological solutions of the Einstein equations, having two hypersurface-orthogonal Killing vectors , with ideal fluid. The equation of state is in the most cases of the form p=gammarhop = \gamma \rhop=gammarho.
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Axially Symmetric Perfect Fluid Cosmological Model in Modified Theory of Gravity
International Journal for Research in Applied Science & Engineering Technology (IJRASET), 2022
With an appropriate choice of the function f (R,T) , an anisotropic Axially Symmetric Space – time filled with perfect fluid in general relativity and also in the framework of f (R,T) gravity proposed by Harko et. al. (in arXiv: 1104. 2669 [grqc],2011) has been studied. The field equations have been solved by using the anisotropy features of the universe in Axially Symmetric Bianchi type- I Space – time. We have been discussed some physical properties of the models. We observed that the involvement of new function f (R,T) does not affect the geometry of the space-time but slightly changes the matter distribution.
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