scholarly journals Two fluid anisotropic dark energy models in a scale invariant theory

2017 ◽  
Vol 132 (9) ◽  
Author(s):  
S. K. Tripathy ◽  
B. Mishra ◽  
P. K. Sahoo
2020 ◽  
Vol 34 (06) ◽  
pp. 2050030
Author(s):  
Mukesh Kumar ◽  
Rekha Jaiswal ◽  
Rashid Zia

In this paper, we have derived the general solutions of the field equations of the Scalar–Tensor theory of gravitation, proposed by Brans and Dicke (1961) within the framework of a locally rotationally symmetric (LRS) metric. We have discussed the anisotropic dark energy models by assuming the time-dependent general scale factor [Formula: see text]. Further, we have discussed the physical and geometric behaviors of the model using different forms of the scale factors. We have also performed a comparative study of the results obtained in various cases. We have observed that the solutions obtained using Hybrid Expansion Law (HEL) are more consistent with recent observations as compared to the rest. Stability of the solutions is also compared using metric perturbations.


2015 ◽  
Vol 24 (02) ◽  
pp. 1550019 ◽  
Author(s):  
M. S. Borkar ◽  
A. Ameen

In this paper, Bianchi type VI0 magnetized anisotropic dark energy models with constant deceleration parameter have been studied by solving the Rosen's field equations in Bimetric theory of gravitation. The models corresponding to power law expansion and exponential law expansion have been evaluated and studied their nature geometrically and physically. It is seen that there is real visible matter (baryonic matter) suddenly appeared only for small interval of time 0.7 ≤ t < 0.7598 and for the remaining whole range of time t, there is dark energy matter in the universe. Our investigations are supported to the observational fact that the usual matter described by known particle theory is about 4% and the dark energy cause the accelerating expansion of the universe and several high precision observational experiments, especially the Wilkinson Microwave Anisotropic Probe (WMAP) satellite experiment (see [C. L. Bennett et al., Astrophys. J. Suppl. Ser. 148 (2003) 1; WMAP Collab. (D. N. Spergel et al.), Astrophys. J. Suppl. Ser. 148 (2003) 175; D. N. Spergel et al., Astrophys. J. Suppl. 170 (2007) 377; WMAP Collab. (E. Komastu et al.), Astrophys. J. Suppl. 180 (2009) 330; WMAP Collab. (G. Hinshaw et al.), Astrophys. J. Suppl. 208 (2013) 19; Plank Collab. (P. A. R. Ade), arXiv:1303.5076; arXiv:1303.5082]) conclude that the dark energy occupies near about 73% of the energy of the universe and dark matter is about 23%. In exponential law of expansion, our model is fully occupied by real visible matter and there is no chance of dark energy and dark matter.


2021 ◽  
Vol 96 (4) ◽  
pp. 045006
Author(s):  
B Mishra ◽  
Fakhereh Md Esmaeili ◽  
Pratik P Ray ◽  
S K Tripathy

2012 ◽  
Vol 342 (1) ◽  
pp. 257-267 ◽  
Author(s):  
Bijan Saha ◽  
Hassan Amirhashchi ◽  
Anirudh Pradhan

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