Probing the cosmographic parameters to distinguish between dark energy and modified gravity models

TL;DR

This study uses high-redshift gamma-ray bursts and supernovae to analyze cosmographic parameters, aiming to differentiate dark energy from modified gravity models, and finds the snap parameter effective for model distinction.

Contribution

It introduces a method to constrain cosmographic parameters using model-independent calibration of GRBs and SNe, and evaluates their effectiveness in distinguishing cosmological models.

Findings

The snap parameter can differentiate certain dark energy and modified gravity models.

The DM model remains consistent with current high-redshift data.

The statefinder pair (r,s) is less effective for model discrimination.

Abstract

In this paper we investigate the deceleration, jerk and snap parameters to distinguish between the dark energy and modified gravity models by using high redshift gamma-ray bursts (GRBs) and supernovae (SNe). We first derive the expressions of deceleration, jerk and snap parameters in dark energy and modified gravity models. In order to constrain the cosmographic parameters, we calibrate the GRB luminosity relations without assuming any cosmological models using SNe Ia. Then we constrain the models (including dark energy and modified gravity models) parameters using type Ia supernovae and gamma-ray bursts. Finally we calculate the cosmographic parameters. GRBs can extend the redshift - distance relation up to high redshifts, because they can be detected to high redshifts.We find that the statefinder pair (r,s) could not be used to distinguish between some dark energy and modified gravity models, but these models could be differentiated by the snap parameter. Using the model-independent constraints on cosmographic parameters, we conclude that the \LambdaCDM model is consistent with the current data.