Cosmology of a generalised version of holographic dark energy in presence of bulk viscosity and its inflationary dynamics through slow roll parameters

TL;DR

This paper develops a holographic dark energy model incorporating bulk viscosity, unifying early inflation with late-time acceleration, and analyzes its stability, inflation exit, and observational consistency with Planck data.

Contribution

It introduces a generalized holographic dark energy model with bulk viscosity, exploring its inflationary dynamics, stability, and observational viability, which is a novel extension of existing models.

Findings

Model unifies phantom inflation with late-time acceleration.

Stable solutions found in interacting and non-interacting scenarios.

Model consistent with Planck observational bounds.

Abstract

The present study reports a reconstruction scheme of a Dark Energy (DE) model with higher order derivative of Hubble parameter, which is a particular case of Nojiri-Odintsov holographic DE [S. Nojiri and S. D. Odintsov, Gen. Relativ. Gravit. 38 (2006) 1285.] that unifies phantom inflation with the acceleration of te universe on late-time. The reconstruction has been carried out in presence of bulk-viscosity, where the bulk-viscous pressure has been taken as a function of Hubble parameter. Ranges of cosmic time $t$ have been derived for quintessence, cosmological constant and phantom behaviour of the equation of state (EoS) parameter. In the viscous scenario, the reconstruction has been carried out in an interacting and non-interacting situations and in both the cases stability against small perturbations has been observed. Finally, the slow roll parameters have been studied and a scope of exit from inflation has been observed. Also, availability of quasi exponential expansion has been demonstrated for interacting viscous scenario and a study through tensor to scalar ratio has ensured consistency of the model with the observational bound by Planck. Alongwith primordial fluctuations the interacting scenario has been found to generate strong dissipative regime.