Abstract:
We propose a logarithmic parametrization form
of energy density for the scalar field dark energy in the
framework of the standard theory of gravity, which supports
the necessary transition from the decelerated to the accelerated behavior of the Universe. The model under consideration is constrained by available observational data, including cosmic chronometers data-sets (CC), Baryonic Acoustic Oscillation (BAO) data-sets, and Supernovae (SN) datasets, consisting of only two parameters α and β. The combined CC+BAO+SN data-sets yields a transition redshift of
ztr = 0.79+0.02 −0.02, where the model exhibits signature-flipping
and is consistent with recent observations. For the combined
data-sets, the present value of the deceleration parameter is
calculated to be q0 = −0.43+0.06 −0.06. Furthermore, the analysis yields constraints on both the parameter density value for
matter and the present value of the Hubble parameter, with
values of m0 = 0.25849+0.00026
−0.00025 and H0 = 67.79+0.59
−0.59
km/s/Mpc, respectively, consistent with the results obtained
from Planck 2018. Finally, the study investigates how the
mass of a black hole evolves over time in a Universe with
both matter and dark energy. It reveals that the black hole
mass increases initially but stops increasing as dark energy
dominates.
