Model independent diagnostics in interacting dark energy models

Abstract

In this paper, we have explored non-gravitational interaction dark energy model between dark energy and cold dark matter (CDM). The main purpose of this work is to explore the deviations from ΛCDM and to distinguish the evolution trajectory of the interaction dark energy model with different parameters. Six forms of interaction were focused on. We have analyzed the deceleration parameters of the coupled model and explored the theoretical models through statefinder hierarchy and the Om diagnostic. We have considered that the Equation of State (EoS) parameter w and parameter ξ take different values on the interaction dark energy model respectively and keep another parameter unchanged. It was found that q(z) is the worst of the four diagnoses. Om, S3(1) and S4(1) are good tools to distinguish the interaction dark energy model from ΛCDM. S3(1) is a better diagnostic tool when the state parameter w changes and the coupling parameter ξ is fixed, while S4(1) works better when the coupling parameter ξ changes and the state parameter w is fixed.