Cosmological constraints on the graviton mass in RTG

The Friedmann cosmological scenario in RTG (without inflation) is considered. The joint maximum-likelihood analysis of data on type Ia supernovae, the shift parameter of microwave radiation, and baryon acoustic oscillations from the Sloan catalogue of red galaxies provided tight fit constraints on the graviton mass and the space curvature in GR. It is demonstrated that the confidence interval for the graviton mass extends indefinitely if the quintessence parameter tends to zero. These conclusions are valid if the present scale factor a ₀ >(2)^?1/6= 0.89. At a ₀ <(2)^?1/6, a tight constraint on the graviton mass was derived from these observational data: m < 10^–83 g. This implies that terms with the graviton mass may be neglected (with the exception of solutions of the black-hole type) in the gravitational field equations in a broad range of redshifts (0 < z < 10¹⁵).