نتایج جستجو برای: anisotropic bianchi type i universe
تعداد نتایج: 2280375 فیلتر نتایج به سال:
Cosmological solutions are obtained in an anisotropic Kantowski-Sachs (KS) and Bianchi Type-I universes considering a cosmological constant with Skyrme fluid. Interestingly, the here both KS Bianchi-I found isotropize at late time due to presence of fluid even absence $\Lambda$ term or any inflationary mechanism involving inflaton field. A comparative study models carried out that universe admi...
In this work we consider particle creation by the expansion of universe, using two Bianchi type I anisotropic models. The particles studied are spin 0 and 1/2. cosmological models have rotational symmetry, which allows us to solve exactly equations motion. number density created is calculated with method Bogolubov transformations.
The one-loop effective potential for φ theory on a Bianchi type-I universe is evaluated in the adiabatic approximation. It is used to see the quantum-field effects on symmetry breaking and restoration in anisotropic spacetimes. The results show that the fate of symmetry will not be changed in the cases of conformal coupling or a vanishing scale curvature, and only for some suitable values of sc...
We obtain a general exact solution of the Einstein field equations for the anisotropic Bianchi type I universes filled with an exponential-potential scalar field and study their dynamics. It is shown, in agreement with previous studies, that for a wide range of initial conditions the late-time behaviour of the models is that of a power-law inflating FRW universe. This property, does not hold, i...
The Cosmic no hair theorem is studied in anisotropic Bianchi brane models which admit power law inflation with a scalar field. We note that all Bianchi models except Bianchi type IX transit to an inflationary regime and the anisotropy washes out at a later epoch. It is found that in the brane world, the anisotropic universe approaches the isotropic phase via inflation much faster than that in t...
Bianchi type-VI0 space time with strange quark matter attached to string cloud in Nordtvedt [1] general scalar tensor theory of gravitation with the help of a special case proposed by Schwinger [2] is obtained. The field equations have been solved by using the anisotropy feature of the universe in the Bianchi type-VI0 space time. Some important features of the model, thus obtained, have been di...
An anisotropic ~Bianchi type I! cosmology is considered in the four-dimensional Neveu-Schwarz–NeveuSchwarz ~NS–NS! sector of low-energy effective string theory coupled to a dilaton and an axionlike H field within a de Sitter–Einstein frame background. The general solution of the gravitational field equations can be expressed in an exact parametric form in both Einstein and string frames. The st...
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