Cosmology with Gravitational Wave/Fast Radio Burst Associations

Abstract

Recently, some theoretical models predicted that a small fraction of fast radio bursts (FRBs) could be associated with gravitational waves (GWs). In this Letter, we discuss the possibility of using GW/FRB association systems, if they are commonly detected in the future, as a complementary cosmic probe. We propose that upgraded standard sirens can be constructed from the joint measurements of luminosity distances D L derived from GWs and dispersion measures DM IGM derived from FRBs (i.e., the combination D L · DM IGM ). Moreover, unlike the traditional standard-siren approach (i.e., the D L method) and the DM IGM method that rely on the optimization of the Hubble constant H 0 , this D L  · DM IGM method has the advantage of being independent of H 0 . Through Monte Carlo simulations, we prove that the D L  · DM IGM method is more effective for constraining cosmological parameters than D L or DM IGM separately, and that it enables us to achieve accurate multimessenger cosmology from approximately 100 GW/FRB systems. Additionally, even if GW/FRB associations do not exist, the methodology developed here can still be applied to those GWs and FRBs that occur at the same redshifts.