Holographic, new agegraphic, and ghost dark energy models in fractal cosmology

Abstract

We investigate the holographic, new agegraphic and ghost dark energy models in the framework of fractal cosmology. We consider a fractal FRW universe filled with the dark energy and dark matter. We obtain the equation of state parameters of the selected dark energy models in the ultraviolet regime and discuss on their implications. Keywords: Dark energy; Fractal cosmology Fractal cosmologyRecently, Calcagni [1, 2] gave a quantum gravity in a fractal universe and then investigated cosmology in that framework. That theory is Lorentz invariant, power-counting renormalizable and free from ultraviolet divergence. In the present paper, we study few DE models (including holographic, new agegraphic and ghost DE) in the framework of fractal cosmology proposed by Calcagni. We calculate their equation of state parameters and discuss their physical implications via graphs and conclude in the end.The action of Einstein gravity in a fractal spacetime is given by [1, 2]where κ 2 = 8πG. Also G, g, R, Λ and L m are the gravitational constant, determinant of metric g µν , Ricci scalar, cosmological constant and Lagrangian density of the total matter inside the universe, respectively. The quantities v and ω are the fractal function and fractal parameter, respectively. Note that d̺(x) is Lebesgue-Stieltjes measure generalizing the standard 4-dimensional measure d 4 x. The scaling dimension of ̺ is [̺] = −4α, where α > 0 is a parameter. The values of α in the infrared (IR) and ultraviolet (UV) regimes are α IR = 1 and α UV = 1/2,

Cosmic Evolution in Fractional Action Cosmology

“…The action in this model is also a Lorentz-covariant and is equipped with a Stieltjes measure, but the model equations are somewhat different from the basic equations of FAC. The holographic, new agegraphic and ghost dark energy models in the framework of fractal cosmology are investigated in [7]. The fractal universe in which dark energy interacting with dark matter is considered in [8].…”

A Study on Some Special Forms of Holographic Ricci Dark Energy in Fractal Universe

“…Sheykhi et al [4] investigated the thermodynamical properties of the apparent horizon in a fractal universe. Karami et al [5] investigated the holographic, the new agegraphic, and the ghost dark energy models in the framework of fractal cosmology, and they also discussed the behavior of the equations of state parameter . In the present work, we are going to investigate the behavior of the modified holographic Ricci dark energy (MHRDE) and the extended holographic Ricci dark energy (EHRDE) models in fractal universe.…”

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