Bianchi type-III String Cosmological Models in Brans-Dicke Theory of Gravity

AUTHOR AND
AFFILIATION

R. K. MISHRA
Department of Mathematics, Sant Longowal Institute of Engineering and Technology, Deemed to be University, Under MHRD, Govt. of India
AVTAR CHAND
Department of Mathematics, Sant Longowal Institute of Engineering and Technology, Deemed to be University, Under MHRD, Govt. of India

KEYWORDS:

Brans-Dicke Theory, Cosmological Constant, Variable Deceleration Parameter

Issue Date:

March 2019

Pages:

11-22

ISSN:

2319-8044 (Online) – 2231-346X (Print)

Source:

Vol.31 – No.3

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DOI:

http://dx.doi.org/10.22147/jusps-A/310301

ABSTRACT:

A Bianchi type-III string cosmological models is investigated in scalar-tensor Brans-Dicke theory of gravity (Phys. Rev. 124, 925, 1961). For an exact solution of modified Einstein ‘s field equations (EFEs), we assumed time varying nature of deceleration parameter (DP) along with relation between scale factor and time, given by a(t)=[talphaet)]1/n , alpha and n are non-negative constants. It is noticed from study that the power index has their own significance on the string cosmological models. It is also analyzed that the string tension density (lambda) is an increasing function of time whereas the energy density(rho) and the cosmological constant (Lambda) are decreasing functions of time and converges to small value at present time. and n are non-negative constants.

Copy the following to cite this Article:

R. K. Mishra; A. Chand, “Bianchi type-III String Cosmological Models in Brans-Dicke Theory of Gravity”, Journal of Ultra Scientist of Physical Sciences, Volume 31, Issue 3, Page Number 11-22, 2019


Copy the following to cite this URL:

R. K. Mishra; A. Chand, “Bianchi type-III String Cosmological Models in Brans-Dicke Theory of Gravity”, Journal of Ultra Scientist of Physical Sciences, Volume 31, Issue 3, Page Number 11-22, 2019

Available from: http://www.ultrascientist.org/paper/1511/bianchi-type-iii-string-cosmological-models-in-brans-dicke-theory-of-gravity


A Bianchi type-III string cosmological models is investigated in scalar-tensor Brans-Dicke theory of gravity (Phys. Rev. 124, 925, 1961). For an exact solution of modified Einstein ‘s field equations (EFEs), we assumed time varying nature of deceleration parameter (DP) along with relation between scale factor and time, given by a(t)=[talphaet)]1/n , alpha and n are non-negative constants. It is noticed from study that the power index has their own significance on the string cosmological models. It is also analyzed that the string tension density (lambda) is an increasing function of time whereas the energy density(rho) and the cosmological constant (Lambda) are decreasing functions of time and converges to small value at present time. and n are non-negative constants.