Revisiting $f(T)$ Teleparallel Gravity with a Parametrized Hubble Parameter and Observational Constraints

Abstract

In this paper, the dynamical behavior of the accelerated expansion of the universe is studied within the framework of $f(T)$ gravity by considering a well-motivated functional form of $f(T)$. A specific form of the Hubble parameter is assumed, which under two different cases, leads to two distinct cosmological models expressed in terms of the redshift parameter $H(z)$, providing insights into cosmic dynamics. These models are employed to explore the expansion history of the universe and the evolution of several cosmological parameters. Using Bayesian statistical techniques based on the $χ^{2}$-minimization method, the median values of the model parameters are determined for both the cosmic chronometer (CC) and the joint (CC + Pantheon) datasets. The evolution of the deceleration parameter, energy density, pressure and the equation of state parameter for dark energy is analyzed. Additionally, the validity of the energy conditions and the nature of the statefinder diagnostic are examined. The present age of the universe is also estimated for the proposed models.

Figures (13)

• Figure 1: For Model-I: The deceleration parameter$(q)$ versus $z$.
• Figure 2: For Model-II: The deceleration parameter$(q)$ versus $z$.
• Figure 3: The best-fit $H(z)$ curve for the proposed models is compared with the $\Lambda CDM$ model.
• Figure 4: For Model-I: Marginalized $1D$ and $2D$ posterior contour map with median values of $H_{0}$, $\gamma$ and $\zeta$ using the Joint dataset.
• Figure 5: For Model-II: Marginalized $1D$ and $2D$ posterior contour map with median values of $H_{0}$, $\gamma$ and $\zeta$ using the Joint dataset.