https://doi.org/10.1140/epjc/s10052-009-1122-z
Regular Article - Theoretical Physics
Generalized holographic and Ricci dark energy models
Institute of Theoretical Physics, School of Physics & Optoelectronic Technology, Dalian University of Technology, Dalian, 116024, People’s Republic of China
* e-mail: lxxu@dlut.edu.cn
Received:
1
June
2009
Revised:
15
July
2009
Published online:
22
August
2009
In this paper, we consider generalized holographic and Ricci dark energy models where the energy densities are given as ρ
R
=3c
2
M
pl
2
Rf(H
2/R) and ρ
h
=3c
2
M
pl
2
H
2
g(R/H
2), respectively; here f(x), g(y) are positive defined functions of the dimensionless variables H
2/R or R/H
2. It is interesting that holographic and Ricci dark energy densities are recovered or recovered interchangeably when the function f(x)=g(y)≡1 or f(x)=Id and g(y)=Id are taken, respectively (for example f(x),g(x)=1−ε(1−x), ε=0or1, respectively). Also, when f(x)≡xg(1/x) is taken, the Ricci and holographic dark energy models are equivalent to a generalized one. When the simple forms f(x)=1−ε(1−x) and g(y)=1−η(1−y) are taken as examples, by using current cosmic observational data, generalized dark energy models are considered. As expected, in these cases, the results show that they are equivalent (ε=1−η=1.312), and Ricci-like dark energy is more favored relative to the holographic one where the Hubble horizon was taken as an IR cut-off. And the suggested combination of holographic and Ricci dark energy components would be 1.312R−0.312H
2, which is
in terms of H
2 and
.
© Springer-Verlag , 2009