Limit on graviton mass from galaxy cluster Abell 1689

TL;DR

This paper revises the upper limit on graviton mass using galaxy cluster Abell 1689, employing dynamical mass models and Yukawa potential deviations, resulting in a bound of less than 1.37×10⁻²⁹ eV.

Contribution

It introduces a new method to constrain graviton mass using galaxy cluster data and Yukawa potential deviations, updating previous bounds based on orbital stability assumptions.

Findings

Bound on graviton mass: m_g < 1.37×10⁻²⁹ eV

Corresponding graviton wavelength: > 9.1×10¹⁹ km

Compatible with alternative gravity models without dark matter

Abstract

To date, the only limit on graviton mass using galaxy clusters was obtained by Goldhaber and Nieto in 1974, using the fact that the orbits of galaxy clusters are bound and closed, and extend up to 580 kpc. From positing that only a Newtonian potential gives rise to such stable bound orbits, a limit on the graviton mass $m_g<10^{-29}$ eV was obtained (PRD 9,1119, 1974). Recently, it has been shown that one can obtain closed bound orbits for Yukawa potential (arXiv:1705.02444), thus invalidating the main \emph{ansatz} used in Goldhaber and Nieto to obtain the graviton mass bound. In order to obtain a revised estimate using galaxy clusters, we use dynamical mass models of the Abell 1689 (A1689) galaxy cluster to check their compatibility with a Yukawa gravitational potential. We assume mass models for the gas, dark matter, and galaxies for A1689 from arXiv:1703.10219 and arXiv:1610.01543, who used this cluster to test various alternate gravity theories, which dispense with the need for dark matter. We quantify the deviations in the acceleration profile using these mass models assuming a Yukawa potential and that obtained assuming a Newtonian potential by calculating the $\chi^2$ residuals between the two profiles. Our estimated bound on the graviton mass ($m_g$) is thereby given by, $m_g < 1.37 \times 10^{-29}$ eV or in terms of the graviton Compton wavelength of, $\lambda_g>9.1 \times 10^{19}$ km at 90\% confidence level.