The Universe With Bulk Viscosity
TLDR
In this paper, an expanding anisotropic universe is found to isotropize during its expansion, but a static universe cannot isotropise, and the cosmological constant decreases with time as ⁄ / t i2.Abstract:
Exact solutions for a model with variable G, ⁄ and bulk viscosity are obtained. Inflationary solutions with constant (de Sitter-type) and variable energy density are found. An expanding anisotropic universe is found to isotropize during its expansion but a static universe cannot isotropize. The gravitational constant is found to increase with time and the cosmological constant decreases with time as ⁄ / t i2 .read more
Citations
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Effective 3-BRANE Brans-Dicke Cosmology
TL;DR: In this article, a Brans-Dicke brane cosmology with two scalar fields inspired from string theories and phenomenological effective cosmological constant is investigated and some features are described in some details, in particular the low and high energies limit.
Journal ArticleDOI
Maxwell Brane Cosmology with Higher-Order String Curvature Corrections, a Nonminimally Coupled Scalar Field, Dark Matter-Dark Energy Interaction and a Varying Speed of Light
TL;DR: In this paper, the cosmological effects of an alternative theory of gravity on the four-dimensional Randall-Sundrum braneworld of type II with a higher-order string curvature term added to the action are investigated.
Journal ArticleDOI
An lrs bianchi type-i cosmological model with time-dependent λ term
J. P. Singh,R. K. Tiwari +1 more
TL;DR: In this article, the authors investigated locally rotationally symmetric Bianchi type-I cosmological model containing stiff matter with a cosmology term proportional to the Hubble parameter and obtained a universe age given by Ht = 0.55 and a decelerating parameter equal to 2σ2/3H2.
Journal ArticleDOI
Bianchi-I Universe with Decaying Vacuum Energy Density and Time Varying Gravitational Constant
TL;DR: Anisotropic Locally Rotationally Symmetric Bianchi-I (LRSBI) model with variable gravitational and cosmological constants in the framework of Einstein's general relativity is investigated in this paper, where the shear scalar is considered to be proportional to the expansion scalar.
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Dirac's large number hypothesis: A journey from concept to implication
TL;DR: In this paper, a large dimensionless number, arising out of ratios of various physical constants, intrigued many scientists, especially Dirac, who arrived at the revolution of large numbers.
References
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Carl H. Brans,R. H. Dicke +1 more
TL;DR: In this paper, the role of Mach's principle in physics is discussed in relation to the equivalence principle and the difficulties encountered in attempting to incorporate Mach's principles into general relativity are discussed.
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TL;DR: In this paper, a cosmological model in which the universe has its critical density and the gravitational and cosmology "constants"G and Λ are time-dependent is presented.
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Cosmological Models with Variable Cosmological and Gravitational “Constants” and Bulk Viscous Models
TL;DR: In this article, a viscous model with variable gravitational and cosmological constant has been considered and several solutions are presented and some are shown to be equivalent to Berman, Kalligas et al. and Brans-Dicke solutions.
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