A Model to Explain Varying $\Lambda$, $G$ and ${\sigma }^2$ Simultaneously

Abstract

Models with varying cosmical parameters, which were earlier regarded constant, are getting attention. However, different models are usually invoked to explain the evolution of different parameters. We argue that whatever physical process is responsible for the evolution of one parameter, should also be responsible for the evolution of others. This means that the different parameters are coupled together somehow. Based on this guiding principle, we investigate a Bianchi type I model with variable $\Lambda$ and $G$, in which $\Lambda$, $G$ and the shear parameter ${\sigma }^2$, all are coupled. It is interesting that the resulting model reduces to the FLRW model for large $t$ with $G$ approaching a constant.

10 pages

References in corpus (15)

• Measurements of Omega and Lambda from 42 High-Redshift Supernovae
• First Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Preliminary Maps and Basic Results
• Type Ia Supernova Discoveries at z>1 From the Hubble Space Telescope: Evidence for Past Deceleration and Constraints on Dark Energy Evolution
• Cosmological Results from High-z Supernovae
• Cosmology of the Planck Era from a Renormalization Group for Quantum Gravity
• Cosmology with Self-Adjusting Vacuum Energy Density from a Renormalization Group Fixed Point
• A New Nucleosynthesis Constraint on the Variation of G
• Consequences on variable Lambda-models from distant Type Ia supernovae and compact radio sources
• `c' is the speed of light, isn't it?
• A study of the angular size-redshift relation for models in which $\Lambda$ decays as the energy density
• Confronting the IR Fixed Point Cosmology with High Redshift Observations
• A Machian Model of Dark Energy
• Study of the Magnitude-Redshift Relation for type Ia Supernovae in a Model resulting from a Ricci-Symmetry
• The magnification of SN 1997ff, the farthest known Supernova
• Is the present expansion of the universe really accelerating?

Cited by in corpus (6)

• Bianchi Type-I Cosmological Models with Variable G and 4Λ$-Terms in General Relativity
• Variable G correction to statefinder parameters of dark energy
• Bianchi I with variable $G$ and $\Lambda$. Self-Similar approach
• A Generalized Solution of Bianchi Type-V Models with Time-dependent $G$ and $\Lambda$
• Five Dimensional Cosmological Models in General Relativity
• Geometrical Origin of the Cosmological Term