**64**: 89-95

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
}=3*c*
^{2}
*M*
_{pl}
^{2}
*Rf*(*H*
^{2}/*R*) and *ρ*
_{
h
}=3*c*
^{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*=0*or*1, 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 1.312*R*−0.312*H*
^{2}, which is
in terms of *H*
^{2} and
.

*© Springer-Verlag , 2009*