Statefinder diagnosis and the interacting ghost model of dark energy

TL;DR

This paper applies the statefinder diagnostic to the ghost dark energy model, analyzing its evolution in flat and non-flat universes, and compares it with observational data and other dark energy models.

Contribution

It introduces the statefinder analysis for the ghost dark energy model, considering interaction and curvature effects, and compares its evolution with observational constraints and other models.

Findings

Ghost dark energy's statefinder trajectory resembles holographic dark energy.

The $ ext{Lambda}$CDM model's statefinder position aligns well with observations.

Models far from $ ext{Lambda}$CDM}$ in statefinder space are ruled out.

Abstract

A new model of dark energy namely "ghost dark energy model" has recently been suggested to interpret the positive acceleration of cosmic expansion. The energy density of ghost dark energy is proportional to the hubble parameter. In this paper we perform the statefinder diagnostic tool for this model both in flat and non-flat universe. We discuss the dependency of the evolutionary trajectories in $s-r$ and $q-r$ planes on the interaction parameter between dark matter and dark energy as well as the spatial curvature parameter of the universe. Eventually, in the light of SNe+BAO+OHD+CMB observational data, we plot the evolutionary trajectories in $s-r$ and $q-r$ planes for the best fit values of the cosmological parameters and compare the interacting ghost model with other dynamical dark energy models. We show that the evolutionary trajectory of ghost dark energy in statefinder diagram is similar to holographic dark energy model. It has been shown that the statefinder location of $\Lambda$CDM is in good agreement with observation and therefore the dark energy models whose current statefinder values are far from the $\Lambda$CDM point can be ruled out.