Ghost dark energy in the DGP braneworld

TL;DR

This paper explores the ghost dark energy model within the DGP braneworld framework, analyzing its cosmological behavior, stability, and comparison with the ΛCDM model, revealing different dynamics with or without interaction between dark sectors.

Contribution

It is the first study to analyze ghost dark energy in the DGP braneworld, including stability, statefinder diagnostics, and interaction effects.

Findings

In absence of interaction, ω_D approaches -1 at late times.

With interaction, ω_D can cross the phantom line -1.

The model shows instability in sound speed squared in all cases.

Abstract

We investigate the ghost model of dark energy in the framework of DGP braneworld. We explore the cosmological consequences of this model by determining the equation of state parameter, $\omega_D$, the deceleration and the density parameters. We also examine the stability of this model by studying the squared of the sound speed in the presence/absence of interaction term between dark energy and dark matter. We find out that in the absence of interaction between two dark sectors of the Universe we have $\omega_D\rightarrow -1$ in the late time, while in the presence of interaction $\omega_D$ can cross the phantom line $-1$. In both cases the squared of sound speed $v_s^2$ does not show any signal of stability. We also determine the statefinder diagnosis of this model as well as the $\omega_D-{\omega}^{\prime}_{D}$ plane and compare the results with the $\Lambda$CDM model. We find that $\omega_D-{\omega}^{\prime}_{D}$ plane meets the freezing region in the absence of interaction between two dark sectors, while it meets both the thawing and the freezing regions in the interacting case.