scholarly journals Nonsingular cosmological models: the massive scalar field case

Pramana ◽  
1988 ◽  
Vol 30 (1) ◽  
pp. 15-27 ◽  
Author(s):  
B S Sathyaprakash ◽  
K P Sinha
Author(s):  
M. P. V. V. Bhaskara Rao ◽  
Y. Aditya ◽  
U. Y. Divya Prasanthi ◽  
D. R. K. Reddy

This paper deals with the construction of locally rotationally symmetric (LRS) Bianchi type-II (B-II) cosmological models obtained by solving Einstein field equations coupled with an attractive massive scalar field (MSF) when the source of gravitation is the mixture of cosmic string cloud and anisotropic dark energy (DE) fluid which are minimally interacting. We have obtained exact cosmological models by using (i) shear scalar is proportional to the scalar expansion of the space–time and (ii) a power-law relation between the average scale factor of the universe and the scalar field. Our models represent string cosmological model and DE model in the presence of MSF. Using our model, we determine cosmological parameters such as energy densities, deceleration parameter, statefinders and equation of state parameter. We, also, present the tension density and energy density of the string. We discuss the physical aspects of these cosmological parameters. It is observed that our models represent accelerated expansion phenomenon of our universe as confirmed by Supernova Ia experiment.


2003 ◽  
Vol 12 (08) ◽  
pp. 1487-1497 ◽  
Author(s):  
G. V. VERESHCHAGIN

Solutions of gravitational equations of gauge theories of gravity in homogeneous isotropic world with massive scalar field are investigated in the case of flat cosmological models. Special attention is dedicated to behavior of solutions on contraction stage. It is shown, that on expansion stage inflationary solutions are generic feature of the model. At the same time on contraction stage an effective equation of state can be similar to the case of massless scalar field p=ρ at the beginning of evolution and tends to the equation of ultrarelativistic gas p=ρ/3. The Hubble parameter tends to some negative value on contraction stage, depending on the mass of the scalar field. Nonsingular solutions in this model are unstable.


2021 ◽  
Vol 103 (12) ◽  
Author(s):  
Parul Jain ◽  
S. Mahesh Chandran ◽  
S. Shankaranarayanan

2003 ◽  
Vol 33 (4) ◽  
pp. 860-866 ◽  
Author(s):  
A.C. Aguiar Pinto ◽  
T.M. Britto ◽  
R. Bunchaft ◽  
F. Pascoal ◽  
F.S.S. da Rosa

2009 ◽  
Author(s):  
D. Georgieva ◽  
I. Stefanov ◽  
M. Todorov ◽  
S. Yazadjiev ◽  
Michail D. Todorov ◽  
...  

Sign in / Sign up

Export Citation Format

Share Document