Generalized holographic dark energy model described at the Hubble length

TL;DR

This paper extends the holographic dark energy model by allowing a slowly varying parameter, analyzing its evolution and showing it can describe the transition from matter-dominated to dark energy-dominated universe.

Contribution

It introduces a generalized holographic dark energy model with a time-varying parameter, providing a better fit to observational data and explaining cosmic transition phases.

Findings

Phantom line crosses from quintessence to phantom regime.

Deceleration parameter indicates transition from deceleration to acceleration.

Model can describe both dark matter era and dark energy dominance.

Abstract

We generalize the holographic dark energy model described in Hubble length IR cutoff by assuming a slowly time varying function for holographic parameter $c^2$. We calculate the evolution of EoS parameter and the deceleration parameter as well as the evolution of dark energy density in this generalized model. We show that the phantom line is crossed from quintessence regime to phantom regime which is in agreement with observation. The evolution of deceleration parameter indicates the transition from decelerated to accelerated expansion. Eventually, we show that the GHDE with HIR cutoff can interpret the pressureless dark matter era at the early time and dark energy dominated phase later.