Neutron stars in the bimetric Scalar-Tensor theory of gravitation. I. new solutions of the field equations

Astrophysics ◽  
1997 ◽  
Vol 40 (3) ◽  
pp. 252-259
Author(s):  
L. Sh. Grigorian ◽  
P. F. Kazarian ◽  
H. F. Khachatrian
Keyword(s):  
Neutron Stars ◽  
Scalar Tensor Theory ◽  
Field Equations ◽  
Tensor Theory ◽  
Theory Of Gravitation

scholarly journals Plane Symmetric Solutions of a Scalar-Tensor Theory of Gravitation

1977 ◽  
Vol 30 (1) ◽  
pp. 109 ◽  
Author(s):  
DRK Reddy
Keyword(s):  
General Relativity ◽  
Empty Space ◽  
Scalar Fields ◽  
Scalar Tensor Theory ◽  
Field Equations ◽  
Plane Symmetric ◽  
Zero Mass ◽  
Tensor Theory ◽  
Special Cases ◽  
Theory Of Gravitation

Plane symmetric solutions of a scalar-tensor theory proposed by Dunn have been obtained. These solutions are observed to be similar to the plane symmetric solutions of the field equations corresponding to zero mass scalar fields obtained by Patel. It is found that the empty space-times of general relativity discussed by Taub and by Bera are obtained as special cases.

scholarly journals Non-Riemannian description of Robinson–Trautman spacetimes in Brans–Dicke theory of gravity

2019 ◽  
Vol 28 (04) ◽  
pp. 1950070
Author(s):  
Muzaffer Adak ◽  
Tekin Dereli ◽  
Yorgo Şenikoğlu
Keyword(s):  
Scalar Field ◽  
Differential Forms ◽  
Scalar Tensor Theory ◽  
Field Equations ◽  
Exterior Differential ◽  
Tensor Theory ◽  
Theory Of Gravitation ◽  
Theory Of Gravity ◽  
Future Reference

The variational field equations of Brans–Dicke scalar-tensor theory of gravitation are given in a non-Riemannian setting in the language of exterior differential forms over four-dimensional spacetimes. A conformally rescaled Robinson–Trautman metric together with the Brans–Dicke scalar field are used to characterize algebraically special Robinson–Trautman spacetimes. All the relevant tensors are worked out in a complex null basis and given explicitly in an appendix for future reference. Some special families of solutions are also given and discussed.

scholarly journals HIGHER DIMENSIONAL SZEKERES' SPACE–TIME IN BRANS–DICKE SCALAR TENSOR THEORY

2004 ◽  
Vol 13 (06) ◽  
pp. 1073-1083
Author(s):  
ASIT BANERJEE ◽  
UJJAL DEBNATH ◽  
SUBENOY CHAKRABORTY
Keyword(s):  
Turning Point ◽  
Coupling Parameter ◽  
Big Bang ◽  
Space Time ◽  
Scalar Tensor Theory ◽  
Field Equations ◽  
Tensor Theory ◽  
Higher Dimensional ◽  
Theory Of Gravitation ◽  
The Big Bang

The generalized Szekeres family of solution for quasi-spherical space–time of higher dimensions are obtained in the scalar tensor theory of gravitation. Brans–Dicke field equations expressed in Dicke's revised units are exhaustively solved for all the subfamilies of the said family. A particular group of solutions may also be interpreted as due to the presence of the so-called C-field of Hoyle and Narlikar and for a chosen sign of the coupling parameter. The models show either expansion from a big bang type of singularity or a collapse with the turning point at a lower bound. There is one particular case which starts from the big bang, reaches a maximum and collapses with the in course of time to a crunch.

scholarly journals Anisotropic Bulk Viscous String Cosmological Model in a Scalar-Tensor Theory of Gravitation

2013 ◽  
Vol 2013 ◽  
pp. 1-5 ◽  
Author(s):  
D. R. K. Reddy ◽  
Ch. Purnachandra Rao ◽  
T. Vidyasagar ◽  
R. Bhuvana Vijaya
Keyword(s):  
Equations Of State ◽  
Momentum Tensor ◽  
Scalar Tensor Theory ◽  
Field Equations ◽  
Physical Conditions ◽  
Bulk Viscous Fluid ◽  
Tensor Theory ◽  
Highly Nonlinear ◽  
Bulk Viscous ◽  
Theory Of Gravitation

Spatially homogeneous, anisotropic, and tilted Bianchi type-VI0model is investigated in a new scalar-tensor theory of gravitation proposed by Saez and Ballester (1986) when the source for energy momentum tensor is a bulk viscous fluid containing one-dimensional cosmic strings. Exact solution of the highly nonlinear field equations is obtained using the following plausible physical conditions: (i) scalar expansion of the space-time which is proportional to the shear scalar, (ii) the barotropic equations of state for pressure and energy density, and (iii) a special law of variation for Hubble’s parameter proposed by Berman (1983). Some physical and kinematical properties of the model are also discussed.

scholarly journals Static plane-symmetric solution of a scalar-tensor theory of gravitation

1983 ◽  
Vol 24 (3) ◽  
pp. 339-342 ◽  
Author(s):  
D. R. K. Reddy ◽  
V. U. M. Rao
Keyword(s):  
Exact Solution ◽  
Symmetric Solution ◽  
Empty Space ◽  
Vacuum Field ◽  
Scalar Tensor Theory ◽  
Field Equations ◽  
Plane Symmetric ◽  
Tensor Theory ◽  
Theory Of Gravitation ◽  
Static Plane

AbstractVacuum field equations in a scalar-tensor theory of gravitation, proposed by Ross, are obtained with the aid of a static plane-symmetric metric. A closed form exact solution to the field equations in this theory is presented which can be considered as an analogue of Taub's empty space-time in Einstein's theory.

The Large Numbers Hypothesis and a Relativistic Theory of Gravitation

1986 ◽  
Vol 39 (3) ◽  
pp. 339 ◽  
Author(s):  
YK Lau ◽  
SJ Prokhovnik
Keyword(s):  
Scalar Field ◽  
Scalar Potential ◽  
Cosmological Term ◽  
Time Dependent ◽  
Scalar Tensor Theory ◽  
Field Equations ◽  
Tensor Theory ◽  
Large Numbers ◽  
Dependent Form ◽  
Theory Of Gravitation

A way to reconcile Dirac's large numbers hypothesis and Einstein's theory of gravitation wasrecently suggested by Lau (1985). It is characterized by the conjecture of a time-dependentcosmological term and gravitational term in Einstein's field equations. Motivated by thisconjecture and the large numbers hypothesis, we formulate here a scalar-tensor theory in terms of an action principle. The cosmological term is required to be spatially dependent as well as time dependent in general. The theory developed is applied to a cosmological model compatible with the large numbers' hypothesis. The time-dependent form of the cosmological term and the scalar potential are then deduced. A possible explanation of the smallness of the cosmological term is also given and the possible significance of the scalar field is speculated.

Holographic dark energy model in Bianchi type VI0 Universe in a scalar–tensor theory of gravitation with hybrid expansion law

2016 ◽  
Vol 94 (12) ◽  
pp. 1338-1343 ◽  
Author(s):  
D.R.K. Reddy ◽  
S. Anitha ◽  
S. Umadevi
Keyword(s):  
Dark Energy ◽  
Bianchi Type ◽  
Holographic Dark Energy ◽  
Space Time ◽  
Scalar Tensor Theory ◽  
Field Equations ◽  
Tensor Theory ◽  
Theory Of Gravitation ◽  
The Universe ◽  
Energy Components

In this paper, we have obtained field equations of Sáez–Ballester (Phys. Lett. A, 113, 467 (1986)) scalar–tensor theory in the presence of two minimally interacting fields; matter and holographic dark energy components in the space–time described by a spatially homogeneous and anisotropic Bianchi type VI0 space–time. We have used the hybrid expansion law, proposed by Akarsu et al. (JCAP, 01, 022 (2014)), to obtain a determinate solution of the field equations. This solution represents a minimally interacting Bianchi type VI0 Sáez–Ballester universe. Physical and kinematical properties of the universe are also studied.

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