Geometrical Diagnostics for Generalized Chaplygin Gas

TL;DR

This paper applies a new diagnostic method called $Om$ to the generalized Chaplygin gas model, using recent observational data to distinguish it from the standard $\\Lambda$CDM model and to estimate the current dark energy equation of state.

Contribution

It introduces the $Om$ diagnostic to analyze the GCG model and compares it with observational data to differentiate it from $\\Lambda$CDM and estimate dark energy parameters.

Findings

$Om$ diagnostic effectively discriminates GCG from $\\Lambda$CDM.

Current dark energy equation of state $w_{0de}=-0.964$ derived from GCG.

GCG model fits observational data within current uncertainties.

Abstract

A new diagnostic method, $Om$ is applied to generalized Chaplygin gas (GCG) model as the unification of dark matter and dark energy. On the basis of the recently observed data: the Union supernovae, the observational Hubble data, the SDSS baryon acoustic peak and the five-year WMAP shift parameter, we show the discriminations between GCG and $\Lambda$CDM model. Furthermore, it is calculated that the current equation of state of dark energy $w_{0de}=-0.964$ according to GCG model.