Next Article in Journal
Gravitational Waves in Einstein-Æther Theory and Generalized TeVeS Theory after GW170817
Previous Article in Journal
Non-Locality and Late-Time Cosmic Acceleration from an Ultraviolet Complete Theory
Article Menu
Issue 8 (August) cover image

Export Article

Open AccessArticle
Universe 2018, 4(8), 83; https://doi.org/10.3390/universe4080083

A Generalized Solution of Bianchi Type-V Models with Time-Dependent G and Λ

1
Department of Physics, University of Khartoum, P.O. Box 321, Khartoum 11115, Sudan
2
Information Technology Department, Napata College, Ryad, Khartoum 11115, Sudan
3
Center for Space Research & Department of Physics, North-West University, Mafikeng 2735, South Africa
4
Faculty of Mathematical Sciences & Statistics, Al-Neelain University, Khartoum 11115, Sudan
*
Author to whom correspondence should be addressed.
Received: 14 June 2018 / Revised: 17 July 2018 / Accepted: 19 July 2018 / Published: 27 July 2018
Full-Text   |   PDF [501 KB, uploaded 27 July 2018]   |  

Abstract

We study the homogeneous but anisotropic Bianchi type-V cosmological model with time-dependent gravitational and cosmological “constants”. Exact solutions of the Einstein field equations (EFEs) are presented in terms of adjustable parameters of quantum field theory in a spatially curved and expanding background. It has been found that the general solution of the average scale factor a as a function of time involved the hypergeometric function. Two cosmological models are obtained from the general solution of the hypergeometric function and the Emden–Fowler equation. The analysis of the models shows that, for a particular choice of parameters in our first model, the cosmological “constant” decreases whereas the Newtonian gravitational “constant” increases with time, and for another choice of parameters, the opposite behaviour is observed. The models become isotropic at late times for all parameter choices of the first model. In the second model of the general solution, both the cosmological and gravitational “constants” decrease while the model becomes more anisotropic over time. The exact dynamical and kinematical quantities have been calculated analytically for each model. View Full-Text
Keywords: cosmological models; Bianchi type-V; varying G and Λ cosmological models; Bianchi type-V; varying G and Λ
Figures

Figure 1

This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. (CC BY 4.0).
SciFeed

Share & Cite This Article

MDPI and ACS Style

Alfedeel, A.H.A.; Abebe, A.; Gubara, H.M. A Generalized Solution of Bianchi Type-V Models with Time-Dependent G and Λ. Universe 2018, 4, 83.

Show more citation formats Show less citations formats

Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.

Related Articles

Article Metrics

Article Access Statistics

1

Comments

[Return to top]
Universe EISSN 2218-1997 Published by MDPI AG, Basel, Switzerland RSS E-Mail Table of Contents Alert
Back to Top