Bound on the graviton mass from Chandra x-ray cluster sample

Abstract

We present new limits on the graviton Compton wavelength in a Yukawa potential using a sample of 12 relaxed galaxy clusters, for which the temperature and gas density profiles were derived by Vikhlinin et al (2006 Astrophys. J. 640 691) using Chandra x-ray observations. These limits can be converted to a bound on the graviton mass, assuming a non-zero graviton mass would lead to a Yukawa potential at these scales. For this purpose, we first calculate the total dynamical mass from the hydrostatic equilibrium equation in Yukawa gravity and then compare it with the corresponding mass in Newtonian gravity. We calculate a 90% c.l. lower/upper limit on the graviton Compton wavelength/ mass for each of the 12 clusters in the sample. The best limit is obtained for Abell 2390, corresponding to km or eV. This is the first proof of principles demonstration of setting a limit on the graviton mass using a sample of related galaxy clusters with x-ray measurements and can be easily applied to upcoming x-ray surveys such as eRosita.