We obtain a constraint on the parameters of a generalized cubic Galileon gravity model exhibiting the Vainshtein mechanism by using multi-wavelength observations of the Coma Cluster. The generalized cubic Galileon model is characterized by three parameters of the turning scale associated with the Vainshtein mechanism, and the amplitude of modifying a gravitational potential and a lensing potential. X-ray and Sunyaev-Zeldovich (SZ) observations of the intra-cluster medium are sensitive to the gravitational potential, while the weak-lensing (WL) measurement is specified by the lensing potential. A joint fit of a complementary multi-wavelength dataset of X-ray, SZ and WL measurements enables us to simultaneously constrain these three parameters of the generalized cubic Galileon model for the first time. We also find a degeneracy between the cluster mass parameters and the gravitational modification parameters, which is influential in the limit of the weak screening of the fifth force.
@article{arxiv.1505.03692,
title = {Testing a generalized cubic Galileon gravity model with the Coma Cluster},
author = {Ayumu Terukina and Kazuhiro Yamamoto and Nobuhiro Okabe and Kyoko Matsushita and Toru Sasaki},
journal= {arXiv preprint arXiv:1505.03692},
year = {2015}
}
Comments
24 page, 7 figures, version accepted for publication in JCAP