https://doi.org/10.1140/epjc/s10052-015-3505-7
Regular Article - Theoretical Physics
Statefinder hierarchy exploration of the extended Ricci dark energy
1
College of Sciences, Shenyang Aerospace University, Shenyang, 110136, China
2
Department of Physics, College of Sciences, Northeastern University, Shenyang, 110004, China
3
Center for High Energy Physics, Peking University, Beijing, 100080, China
* e-mail: yufei@sau.edu.cn
Received:
23
April
2015
Accepted:
2
June
2015
Published online:
23
June
2015
We apply the statefinder hierarchy plus the fractional growth parameter to explore the extended Ricci dark energy (ERDE) model, in which there are two independent coefficients and . By adjusting them, we plot evolution trajectories of some typical parameters, including the Hubble expansion rate E, deceleration parameter q, the third- and fourth-order hierarchy and , and the fractional growth parameter , respectively, as well as several combinations of them. For the case of variable and constant , in the low-redshift region the evolution trajectories of E are in high degeneracy and that of q separate somewhat. However, the CDM model is confounded with ERDE in both of these cases. and , especially the former, perform much better. They can differentiate well only varieties of cases within ERDE except CDM in the low-redshift region. For the high-redshift region, combinations can break the degeneracy. Both of and have the ability to discriminate ERDE with from CDM, of which the degeneracy cannot be broken by all the before-mentioned parameters. For the case of variable and constant , and can only discriminate ERDE from CDM. Nothing but pairs and can discriminate not only within ERDE but also ERDE from CDM. Finally, we find that is surprisingly a better choice to discriminate within ERDE itself, and ERDE from CDM as well, rather than .
© The Author(s), 2015