Constraining cosmic dark energy using bright standard sirens

Abstract

We use mock gravitational-wave standard siren events from various supermassive black hole binary population models to constrain the dark energy parameters of a spatially-flat Chevalier-Polarski-Linder (CPL) cosmological model. In all cases, we find consistency in the approach, recovering the fiducial parameters regardless of the uncertainty in the supermassive black hole population models. We report constraints with sub-sigma deviation 0.03σ–0.92σ, adding support to the feasibility of bright standard sirens for constraining the flat CPL dark energy model. This highlights the potential of gravitational waves as a probe of the expansion of the universe and the properties of dark energy.