Constraining deceleration, jerk and transition redshift using cosmic chronometers, Type Ia supernovae and ISW effect

TL;DR

This paper constrains the deceleration, jerk, and transition redshift parameters of the universe using cosmic chronometers, supernovae, and ISW effect data, highlighting challenges in direct measurement methods for non-Lambda-CDM models.

Contribution

It introduces a method to constrain cosmological parameters using multiple observational data sets and discusses the limitations of direct measurements in non-Lambda-CDM models.

Findings

Constraints on deceleration and jerk parameters from observational data.

Identification of issues with direct measurement methods for non-Lambda-CDM models.

Derived transition redshift values for different cosmological models.

Abstract

In this study we present constraints on the deceleration (q) and jerk (j) parameters using the late time integrated Sachs-Wolfe effect, type Ia supernovae, and H(z) data . We first directly measure the deceleration and jerk parameters using the cosmic chronometers data with the Taylor series expression of H(z).However, due to the unusual variations in the deceleration parameter with slight changes in other parameters like snap (s) and lerk (l), we found that direct measurements using the series expression of the H(z) is not a suitable method for non-Lambda-CDM models and so we will need to derive the deceleration parameter after constraining density parameters and dark energy equation of state parameters. Then we present derived values of the deceleration parameter from Lambda CDM, WCDM and CPL models. We also discuss the transition redshift (zt) in relation with the deceleration parameter.