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241.
Using the Friedmann equation in rainbow Universe, we obtain an exact scalar field Inflationary Solution, which is a modification
of the exact scalar field with negative potential −V
0+m
2
φ
2/2. Because the rainbow metric is Finsler metric, the result in this paper implies that the research of Finsler geometry in
Cosmology should lead to several new physics theories. 相似文献
242.
G. S. Khadekar Gopal L. Kondawar Cenap Ozel 《International Journal of Theoretical Physics》2008,47(7):1844-1852
The field equations with variable cosmological and gravitational constants are consider in the presence of perfect fluid for
Kaluza-Klein type cosmological model. The exact solutions of the field equations are obtained by using the gamma law equation
of state p=(γ−1)ρ in which the parameter γ depends on scale factor R. The functional form of γ(R) is used to analyze a wide range of cosmological solution at early universe for two phases in cosmic history: inflationary phase and radiation dominated phase. The corresponding physical interpretation of cosmological solution are also discussed in the framework of higher dimensional
space time. 相似文献
243.
Anirudh Pradhan Vandana Rai Kanti Jotania 《理论物理通讯》2008,50(7):279-288
Cylindrically symmetric inhomogeneous cosmological model for bulk viscous fluid distribution with electro- magnetic field is obtained. The source of the magnetic field is due to an electric current produced along the z-axis. F12 is the non-vanishing component of electromagnetic field tensor. To get the deterministic solution, it has been assumed that the expansion 0 in the model is proportional to the shear σ. The values of cosmological constant for these models are found to be small and positive at late time, which are consistent with the results from recent supernovae Ia observations. Physical and geometric aspects of the models are also discussed in presence and absence of magnetic field. 相似文献
244.
In this paper, the cosmological model of the Universe has been presented in gravity and the parameters are constrained from the cosmological data sets. At the beginning, a well motivated form of has been employed, where α, β, and n are model parameters. The Hubble parameter is obtained in redshift with some algebraic manipulation from the considered form of . Then it is parameterized with the recent data and data using Markov chain Monte Carlo analysis. The obtained model parameter values are validated with the baryon acoustic oscillation data set. A parametrization of the cosmographic parameters shows the early deceleration and late time acceleration with the transition at . The diagnostics gives positive slope which shows that the model is in the phantom phase. Also the current age of the Universe has been obtained as, . Based on the present analysis, it indicates that the gravity may provide an alternative to dark energy for addressing the current cosmic acceleration. 相似文献