Constraints on Quasi-dilaton Massive Gravity

TL;DR

This paper constrains the graviton mass in quasi-dilaton massive gravity using astrophysical observations, finding an upper bound consistent with other tests, but still too small for current detection capabilities.

Contribution

It provides the first astrophysical upper bound on the graviton mass in QDMG, linking theory with observational constraints.

Findings

Upper bound on graviton mass: $m \,\leq 10^{-31}$ eV

Consistent with LIGO and Solar System bounds

LISA's sensitivity can probe up to $m \,\leq 10^{-25}$ eV

Abstract

The last decade has seen great advancements in the field of modified gravity, motivated by the dark energy problem, or by the search for a fundamental quantum gravity theory. With a phenomenologically-driven approach, we consider dRGT theory and its extension, quasi-dilaton massive gravity (QDMG). When looking for ways to constrain the theory, a promising direction appeared to be astrophysical tests. The scalar gravitational degree of freedom and quasi-dilaton degree of freedom alter the evolution of Bardeen potentials, which in turn affects the galaxy rotation curves. We find an upper bound on graviton mass in QDMG to be $m \leq 10^{-31} {\rm eV}$. This result agrees with bounds from LIGO and numerous Solar System tests. However, the extremely small mass of the graviton remains a detection out of reach, with LISA's sensitivity exploring the parameter space up to $m \leq 10^{-25} {\rm eV}$.