Cosmological Evolution of Interacting New Holographic Dark Energy in Non-flat Universe
M. Sharif, Abdul Jawad
TL;DR
The paper investigates holographic dark energy in a non-flat universe using a new infrared cutoff and an interaction with dark matter. It derives the evolution of the EoS parameter $\omega$ and the squared sound speed $\upsilon_s^2$, showing evolution from vacuum-like to quintessence regimes for certain parameters and highlighting classical instability. It also maps NHDE onto scalar-field descriptions (quintessence, tachyon, K-essence, and dilaton) and provides an analytic solution for $E^2$ that encapsulates curvature, matter, and NHDE contributions, indicating accelerated expansion. Additionally, the generalized second law of thermodynamics is discussed within this framework, linking holographic dynamics to thermodynamic viability and observational consistency.
Abstract
We consider the interacting holographic dark energy with new infrared cutoff (involving Hubble parameter and its derivative) in non-flat universe. In this context, we obtain the equation of state parameter which evolutes the universe from vacuum dark energy region towards quintessence region for particular values of constant parameters. It is found that this model always remains unstable against small perturbations. Further, we establish the correspondence of this model having quintessential behavior with quintessence, tachyon, K-essence and dilaton scalar field models. The dynamics of scalar fields and potentials indicate accelerated expansion of the universe which is consistent with the current observations. Finally, we discuss the validity of the generalized second law of thermodynamics in this scenario.