English

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

Cosmology and Nongalactic Astrophysics 2024-04-30 v3 General Relativity and Quantum Cosmology

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 qq parameter is qiq_{i}, the final value is qfq_f, the present value is denoted by q0q_{0}, and the transition duration is given by α\alpha. 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 qfq_{f} is unrestricted, when qfq_{f} is equal to 1-1, and when α\alpha is 1/31/3. This is done assuming that qi=1/2q_{i}=1/2. Here, we achieve that the SNSN data fixes the free parameters tightly as in the flat Λ\LambdaCDM for unrestricted qfq_{f}. In addition, if we fix qf=1q_{f}=-1, the model behaves well as the Λ\LambdaCDM 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\LambdaCDM model. Furthermore, we observe a deviation from the standard Λ\LambdaCDM model in the current model based on the evolution of j(z)j(z), and it is evident that the universe transitions from deceleration to acceleration and will eventually reach the Λ\LambdaCDM model in the near future.

Keywords

Cite

@article{arxiv.2312.06464,
  title  = {Revisiting kink-like parametrization and constraints using OHD/Pantheon+/BAO samples},
  author = {Simran Arora and P. K. Sahoo},
  journal= {arXiv preprint arXiv:2312.06464},
  year   = {2024}
}

Comments

Physics of the Dark Universe published version

R2 v1 2026-06-28T13:47:14.367Z