Observational constraints on the jerk parameter with the data of the Hubble parameter

Abstract

We study the accelerated expansion phase of the universe by using the kinematic approach. In particular, the deceleration parameter q is parametrized in a model-independent way. Considering a generalized parametrization for q, we first obtain the jerk parameter j (a dimensionless third time derivative of the scale factor) and then confront it with cosmic observations. We use the latest observational dataset of the Hubble parameter H(z) consisting of 41 data points in the redshift range of 0.07 ≤ z ≤ 2.36, larger than the redshift range that covered by the Type Ia supernova. We also acquire the current values of the deceleration parameter q0, jerk parameter j0 and transition redshift zt (at which the expansion of the universe switches from being decelerated to accelerated) with 1σ errors (68.3% confidence level). As a result, it is demonstrate that the universe is indeed undergoing an accelerated expansion phase following the decelerated one. This is consistent with the present observations. Moreover, we find the departure for the present model from the standard ΛCDM model according to the evolution of j. Furthermore, the evolution of the normalized Hubble parameter is shown for the present model and it is compared with the dataset of H(z).

A generalized interacting Tsallis holographic dark energy model and its thermodynamic implications

“…This explains both the observed growth of structures at the early times and the late time cosmic acceleration measurements. Also, the transition between the DM era and the THDE era takes place within the redshift interval [0.637,0.962], which are in good compatibility with several recent studies [81][82][83][84][85][86][87][88][89][90]. It is also observed that j stays positive and approaches to the CDM ( j = 1) model as z → −1.…”

“…3. From this figure, it is clear that our model can describe the current accelerated universe, and the transition redshift z t (i.e., q(z t ) = 0) from the deceleration phase to an accelerated phase occurs within the intervals [0.637, 0.962] (for upper panel) and [0.776, 0.889] (for lower panel), which are in good agreement with the results, 0.5 < z t < 1, as reported in [81][82][83][84][85][86][87][88][89][90]. The evolution of j (z) has also been plotted in Fig.…”

“…It is well known that the jerk parameter, a dimensionless third derivative of the scale factor with respect to cosmic time, provides a comparison between different DE models and the CDM ( j = 1) model. It is given by [80][81][82]…”

Cosmological test on viscous bulk models using Hubble parameter measurements and type Ia supernovae data

“…In this phasespace, LCDM is a fixed point located at (s, r) = (0, 1), the trajectories in the region r < 1 and s > 0 corresponds to quintessence behaviour and trajectories in the region r < 1 and s < 0 presents a Chaplygin gas one. The jerk parameter can be expressed in terms of q(z) and its first derivative with respect to z as [61]…”

Implications of JLA data for k-essence model of dark energy with given equation of state

“…q(z) is positive (negative) for a decelerating (accelerating) universe. Evolution of the jerk parameter j(z) is relevant in search for for departure from Λ-CDM model [85]. Exploiting the d/dt = −(1 + z)H(z)d/dz in above equations we in above equations we express q(z) and j(z) as…”