| Abstract: | A new dark energy model in anisotropic Bianchi type-I (B-I) space-time with time dependent equation of state (EoS) parameter
and constant deceleration parameter has been investigated in the present paper. The Einstein’s field equations have been solved
by applying a variation law for generalized Hubble’s parameter (Berman in Il Nuovo Cimento B 74:182, 1983) which generates two types of solutions, one is of power-law type and other is of the exponential form. The existing range
of the dark energy EoS parameter ω for derived model is found to be in good agreement with the three recent observations (i) SNe Ia data (Knop et al. in Astrophys.
J. 598:102, 2003), (ii) SNe Ia data collaborated with CMBR anisotropy and galaxy clustering statistics (Tegmark et al. in Astrophys. J. 606:702,
2004) and (iii) a combination of cosmological datasets coming from CMB anisotropies, luminosity distances of high redshift type
Ia supernovae and galaxy clustering (Hinshaw et al. in Astrophys. J. Suppl. Ser. 180:225, 2009 and Komatsu et al. in Astrophys. J. Suppl. Ser. 180:330, 2009). The cosmological constant Λ is found to be a decreasing function of time and it approaches a small positive value at the
present epoch which is corroborated by results from recent supernovae Ia observations. It has also been suggested that the
dark energy that explains the observed accelerating universe may arise due to the contribution to the vacuum energy of the
EoS in a time dependent background. Geometric and kinematic properties of the model and the behaviour of the anisotropy of
the dark energy have been carried out. |
