Astronomy and Astrophysics – Astrophysics – General Relativity and Quantum Cosmology
Scientific paper
2001-10-29
Int.J.Mod.Phys.D11:1265-1284,2002
Astronomy and Astrophysics
Astrophysics
General Relativity and Quantum Cosmology
14 pages, 15 figures
Scientific paper
10.1142/S0218271802002232
We consider the evolution of a flat Friedmann-Robertson-Walker Universe, filled with a causal bulk viscous cosmological fluid, in the presence of variable gravitational and cosmological constants. The basic equation for the Hubble parameter, generalizing the evolution equation in the case of constant gravitational coupling and cosmological term, is derived, under the supplementary assumption that the total energy of the Universe is conserved. By assuming that the cosmological constant is proportional to the square of the Hubble parameter and a power law dependence of the bulk viscosity coefficient, temperature and relaxation time on the energy density of the cosmological fluid, two classes of exact solutions of the field equations are obtained. In the first class of solutions the Universe ends in an inflationary era, while in the second class of solutions the expansion of the Universe is non-inflationary for all times. In both models the cosmological "constant" is a decreasing function of time, while the gravitational "constant" increases in the early period of evolution of the Universe, tending in the large time limit to a constant value.
Belinchón José Antonio
Harko Tiberiu
Mak Man-Kin
No associations
LandOfFree
Causal Bulk Viscous Dissipative Isotropic Cosmologies with Variable Gravitational and Cosmological Constants does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Causal Bulk Viscous Dissipative Isotropic Cosmologies with Variable Gravitational and Cosmological Constants, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Causal Bulk Viscous Dissipative Isotropic Cosmologies with Variable Gravitational and Cosmological Constants will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-73131