https://doi.org/10.1140/epjc/s10052-016-3907-1
Regular Article - Theoretical Physics
Interacting scalar tensor cosmology in light of SNeIa, CMB, BAO and OHD observational data sets
1
Department of Physics, Faculty of Science University of Kurdistan, Sanandaj, Iran
2
Institute for Advance Studies in Basic Sciences (IASBS) Gava Zang, Zanjan, 45137-66731, Iran
3
Sanandaj Branch Islamic Azad University, Sanandaj, Iran
* e-mail: h.sh.ahmadi@gmail.com
** e-mail: h.sh.ahmadi@iasbs.ac.ir
Received:
29
June
2015
Accepted:
25
January
2016
Published online:
8
February
2016
In this work, an interacting chameleon-like scalar field scenario, by considering SNeIa, CMB, BAO, and OHD data sets, is investigated. In fact, the investigation is realized by introducing an ansatz for the effective dark energy equation of state, which mimics the behavior of chameleon-like models. Based on this assumption, some cosmological parameters, including the Hubble, deceleration, and coincidence parameters, in such a mechanism are analyzed. It is realized that, to estimate the free parameters of a theoretical model, by regarding the systematic errors it is better that the whole of the above observational data sets would be considered. In fact, if one considers SNeIa, CMB, and BAO, but disregards OHD, it maybe leads to different results. Also, to get a better overlap between the contours with the constraint 
, the 
function could be re-weighted. The relative probability functions are plotted for marginalized likelihood 
according to the two dimensional confidence levels 68.3, 90, and 
. Meanwhile, the value of the free parameters which maximize the marginalized likelihoods using the above confidence levels are obtained. In addition, based on these calculations the minimum value of 
based on the free parameters of the ansatz for the effective dark energy equation of state is achieved.
© The Author(s), 2016
