Testing a generalized cubic Galileon gravity model with the Coma Cluster

TL;DR

This paper constrains a generalized cubic Galileon gravity model using multi-wavelength observations of the Coma Cluster, combining X-ray, SZ, and weak-lensing data to simultaneously limit model parameters for the first time.

Contribution

It introduces a joint analysis method that constrains the parameters of a generalized cubic Galileon gravity model using multi-wavelength cluster observations.

Findings

Constraints on the three parameters of the model were obtained.

Degeneracy between cluster mass and gravity modification parameters was identified.

First simultaneous constraints on these parameters using combined data.

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.