$w_d=-1$ in interacting quintessence model

TL;DR

This paper examines a quintessence dark energy model interacting with dark matter, analyzing conditions for reaching the cosmological constant boundary and how the interaction influences the dark energy and dark matter ratio.

Contribution

It identifies the conditions under which the interacting quintessence model can achieve $w_d=-1$ and explores how the potential and interaction constrain the dark sector ratio.

Findings

Reaching $w_d=-1$ depends on the potential and interaction details.

Interaction constraints are necessary for crossing the phantom divide.

The dark matter to dark energy ratio at $w_d=-1$ is influenced by the model parameters.

Abstract

A model consisting of quintessence scalar field interacting with cold dark matter is considered. Conditions required to reach $w_d=-1$ are discussed. It is shown that depending on the potential considered for the quintessence, reaching the phantom divide line puts some constraints on the interaction between dark energy and dark matter. This also may determine the ratio of dark matter to dark energy density at $w_d=-1$.