https://doi.org/10.1140/epjc/s10052-018-5616-4
Regular Article - Theoretical Physics
Testing backreaction effects with observational Hubble parameter data
1
Dezhou University, Dezhou, 253023, China
2
Department of Astronomy, Beijing Normal University, Beijing, 100875, China
3
Tsung-Dao Lee Institute, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai, 200240, China
4
National Astronomical Observatories, Chinese Academy of Sciences, Beijing, 100012, China
* e-mail: tjzhang@bnu.edu.cn
Received:
18
November
2017
Accepted:
5
February
2018
Published online:
26
February
2018
The spatially averaged inhomogeneous Universe includes a kinematical backreaction term 
that is relate to the averaged spatial Ricci scalar 
in the framework of general relativity. Under the assumption that and obey the scaling laws of the volume scale factor 
, a direct coupling between them with a scaling index n is remarkable. In order to explore the generic properties of a backreaction model for explaining the accelerated expansion of the Universe, we exploit two metrics to describe the late time Universe. Since the standard FLRW metric cannot precisely describe the late time Universe on small scales, the template metric with an evolving curvature parameter 
is employed. However, we doubt the validity of the prescription for 
, which motivates us apply observational Hubble parameter data (OHD) to constrain parameters in dust cosmology. First, for FLRW metric, by getting best-fit constraints of 
, 
, and 
, the evolutions of parameters are explored. Second, in template metric context, by marginalizing over 
as a prior of uniform distribution, we obtain the best-fit values of 
and 
. Moreover, we utilize three different Gaussian priors of , which result in different best-fits of n, but almost the same best-fit value of 
. Also, the absolute constraints without marginalization of parameter are obtained: 
and 
. With these constraints, the evolutions of the effective deceleration parameter 
indicate that the backreaction can account for the accelerated expansion of the Universe without involving extra dark energy component in the scaling solution context. Nevertheless, the results also verify that the prescription of is insufficient and should be improved.
© The Author(s), 2018
