A Time-Dependent Λ and G Cosmological Model Consistent with Cosmological Constraints
Author
Source
Issue
Vol. 2016, Issue 2016 (31 Dec. 2016), pp.1-8, 8 p.
Publisher
Hindawi Publishing Corporation
Publication Date
2016-06-08
Country of Publication
Egypt
No. of Pages
8
Main Subjects
Abstract EN
The prevailing constant Λ-G cosmological model agrees with observational evidence including the observed red shift, Big Bang Nucleosynthesis (BBN), and the current rate of acceleration.
It assumes that matter contributes 27% to the current density of the universe, with the rest (73%) coming from dark energy represented by the Einstein cosmological parameter Λ in the governing Friedmann-Robertson-Walker equations, derived from Einstein’s equations of general relativity.
However, the principal problem is the extremely small value of the cosmological parameter (~10−52 m2).
Moreover, the dark energy density represented by Λ is presumed to have remained unchanged as the universe expanded by 26 orders of magnitude.
Attempts to overcome this deficiency often invoke a variable Λ-G model.
Cosmic constraints from action principles require that either both G and Λ remain time-invariant or both vary in time.
Here, we propose a variable Λ-G cosmological model consistent with the latest red shift data, the current acceleration rate, and BBN, provided the split between matter and dark energy is 18% and 82%.
Λ decreases (Λ~τ-2, where τ is the normalized cosmic time) and G increases (G~τn) with cosmic time.
The model results depend only on the chosen value of Λ at present and in the far future and not directly on G.
American Psychological Association (APA)
Kantha, Lakshmi. 2016. A Time-Dependent Λ and G Cosmological Model Consistent with Cosmological Constraints. Advances in Astronomy،Vol. 2016, no. 2016, pp.1-8.
https://search.emarefa.net/detail/BIM-1079409
Modern Language Association (MLA)
Kantha, Lakshmi. A Time-Dependent Λ and G Cosmological Model Consistent with Cosmological Constraints. Advances in Astronomy No. 2016 (2016), pp.1-8.
https://search.emarefa.net/detail/BIM-1079409
American Medical Association (AMA)
Kantha, Lakshmi. A Time-Dependent Λ and G Cosmological Model Consistent with Cosmological Constraints. Advances in Astronomy. 2016. Vol. 2016, no. 2016, pp.1-8.
https://search.emarefa.net/detail/BIM-1079409
Data Type
Journal Articles
Language
English
Notes
Includes bibliographical references
Record ID
BIM-1079409