A model of holographic dark energy

Abstract

A model for holographic dark energy is proposed, following the idea that the short distance cut-off is related to the infrared cut-off. We assume that the infrared cut-off relevant to the dark energy is the size of the event horizon. With the input Ω Λ = 0.73, we predict the equation of state of the dark energy at the present time be characterized by w = −0.90. The cosmic coincidence problem can be resolved by inflation in our scenario, provided we assume the minimal number of e-foldings. March, 2004

Thermodynamical description of the interaction between holographic dark energy and dark matter

“…We shall focus on the DE model inspired by the holographic idea that the energy within our horizon cannot exceed the mass of a black hole of the same size [26,27,28]. The extension of the holographic principle to a general cosmological setting was first addressed by Fischler and Susskind [29] and subsequently got modified by many authors [30]- [34].…”

“…The idea of holography has further been applied to the study of inflation and gives possible upper limits to the number of e-folds [37]. Recently, holography has again been proved as an effective way to investigate dark energy [27,38]. Thus holography seems a useful tool to investigate cosmology.…”

“…Introducing the dimensionless density parameter for DE, Ω D = 8πρ D /(3H 2 ), the event horizon radius can be written as [27] …”

Why is the running vacuum energy more benign than the holographic Ricci dark energy?

“…The parameters C 0 , C H and C _ H are constants. In addition, the constant 1 C 0 is given by [11,14] 5) and 0 Ã ¼ Ã ðH 0 Þ is the energy density defined at the present time t 0 or equivalently at the current Hubble rate H 0 ¼ Hðt 0 Þ. In addition, M i is the masses of particles contributing in the loops [12].…”

“…Nevertheless, we would like to highlight that there are several promising candidates as theoretical directions to the dark energy problem from the point of view of fundamental physics. An important candidate, inspired on applying the holographic principle to the Universe as a whole, was advanced and named the holographic dark energy scenario [5,6] whose energy density is inversely proportional to the square of an appropriate length L that characterizes the size of the system, in this case the Universe, and representing the infrared (IR) cutoff of it. One of the natural choices of this length L is the inverse of the Hubble rate.…”