Extracting $H_{0}$ and $r_{d}$ in Pacif Parametrization Models through Late-Time Dataset

Abstract

This study examines five models derived from the Pacif parametrization scheme of the Hubble parameter ($H$), yielding various linear to quintic forms of the deceleration parameter (DP). Our goal is to explore the impact of these DP variations on late-time evolution and their potential to alleviate cosmological tensions. To enhance model constraints, we introduce non-diagonal elements into the covariance matrix to better capture statistical properties by simulating data point correlations. We also test the sensitivity of $H_{0}$ and $r_{d}$ to the Pacif parametrization scheme, treating the sound horizon $r_{d}$ as a free parameter to avoid imposing a CMB prior. This allows late-time data to constrain $r_{d}$ alongside other cosmological parameters, incorporating recent Baryon Acoustic Oscillations (BAO) measurements and Hubble data from Cosmic Chronometers Methods, Type Ia Supernovae (SNIa), Gamma-Ray Bursts (GRBs), and Quasars over a redshift range of $0.106 < z < 2.33$. Our analysis provides optimal fit values for $H_{0}$ and $r_{d}$, showing notable consistency with Planck CMB data. By using the Akaike information criterion, we analyze the models and conclude that all models have good agreement with the most recent observations.