On a phenomenology of the accelerated expansion with a varying ghost dark energy

TL;DR

This paper explores a phenomenological model of varying ghost dark energy to explain the universe's accelerated expansion, analyzing its theoretical implications and observational constraints through luminosity distance and hierarchy diagnostics.

Contribution

It introduces a new phenomenological variation of ghost dark energy and compares its predictions with observational data using $Om$ and statefinder diagnostics.

Findings

Preliminary constraints on model parameters from luminosity distance fit.

Analysis of interaction effects between dark energy and dark matter.

Discussion of model behavior via hierarchy diagnostics.

Abstract

Subject of our study it is the accelerated expansion of the large scale universe, where a varying ghost dark energy can take the role of the dark energy. The model of the varying ghost dark energy considered in this work it is a phenomenological modification of the ghost dark energy. Recently, three other phenomenological models of the varying ghost dark energy have been suggested and the model considered in this work will complete the logical chain of considered modifications. The best fit of theoretical results to the luminosity distance, has been used to obtain preliminary constraints on the parameters of the models. This does help us to reduce amount of discussion. On the other hand, detailed comparison of theoretical results with observational data has been left as a subject of another discussion elsewhere. Moreover, a look to considered models via $Om$ and statefinder hierarchy analysis is presented and discussed for different forms of interaction between the varying ghost dark energy and cold dark matter.