Revisiting kink-like parametrization and constraints using OHD/Pantheon+/BAO samples

Simran Arora; P. K. Sahoo

doi:10.1016/j.dark.2024.101510

paper

Revisiting kink-like parametrization and constraints using OHD/Pantheon+/BAO samples

arXiv:2312.06464 · doi:10.1016/j.dark.2024.101510

Abstract

We reexamine the kink-like parameterization of the deceleration parameter to derive constraints on the transition redshift from cosmic deceleration to acceleration. This is achieved using observational Hubble data, Type Ia Supernovae Pantheon+ samples and Baryon acoustic oscillations. In this parametrization, the value of the initial $q$ parameter is $q_{i}$ , the final value is $q_{f}$ , the present value is denoted by $q_{0}$ , and the transition duration is given by $α$ . We perform our calculations using the Monte Carlo Markov Chain method, utilizing the emcee package. Under the assumption of a flat geometry, we constrain the range of possible values for three scenarios: when $q_{f}$ is unrestricted, when $q_{f}$ is equal to $- 1$ , and when $α$ is $1/3$ . This is done assuming that $q_{i} = 1/2$ . Here, we achieve that the $S N$ data fixes the free parameters tightly as in the flat $Λ$ CDM for unrestricted $q_{f}$ . In addition, if we fix $q_{f} = - 1$ , the model behaves well as the $Λ$ CDM for the combined dataset. We also acquire the current value of the deceleration parameter, which is consistent with the latest results that assume the $Λ$ CDM model. Furthermore, we observe a deviation from the standard $Λ$ CDM model in the current model based on the evolution of $j (z)$ , and it is evident that the universe transitions from deceleration to acceleration and will eventually reach the $Λ$ CDM model in the near future.

arXiv commentPhysics of the Dark Universe published version

Revisiting kink-like parametrization and constraints using OHD/Pantheon+/BAO samples

Abstract

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