We present the latest measurements of the Hubble parameter and of the parameter $\Xi_0$ describing modified gravitational wave propagation, obtained from the third gravitational wave transient catalog, GWTC-3, using the correlation with galaxy catalogs and information from the source-frame mass distribution of binary black holes. The latter leads to the tightest bound on $\Xi_0$ so far, i.e. $\Xi_0 = 1.2^{ +0.7}_{ -0.7}$ with a flat prior on $\Xi_0$, and $\Xi_0 = 1.0^{ +0.4}_{ -0.8}$ with a prior uniform in $\log\Xi_0$ (Max posterior and $68\%$ HDI). The measurement of $H_0$ is dominated by the single bright siren GW170817, resulting in $H_0=67^{ +9}_{ -6} \, \rm km \, s^{ -1} \, Mpc$ when combined with the galaxy catalog.
Categories: gr-qc astro-ph.CO