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arXiv · 1505.03692

Testing a generalized cubic Galileon gravity model with the Coma Cluster

Ayumu Terukina·Kazuhiro Yamamoto·Nobuhiro Okabe·Kyoko Matsushita·Toru Sasaki
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Abstract

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.

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Ayumu Terukina, Kazuhiro Yamamoto, Nobuhiro Okabe, Kyoko Matsushita, Toru Sasaki. 2015-11-20. Testing a generalized cubic Galileon gravity model with the Coma Cluster. https://doi.org/10.1088/1475-7516%2F2015%2F10%2F064

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