A model-independent constraint on the Hubble constant with gravitational
  waves from the Einstein Telescope
  In this paper, we investigate the expected constraints on the Hubble constant
from the gravitational-wave standard sirens, in a
cosmological-model-independent way. In the framework of the well-known Hubble
law, the GW signal from each detected binary merger in the local universe
($z<0.10$) provides a measurement of luminosity distance $D_L$ and thus the
Hubble constant $H_0$. Focusing on the simulated data of gravitational waves
from the third-generation gravitational wave detector (the Einstein Telescope,
ET), combined with the redshifts determined from electromagnetic counter parts
and host galaxies, one can expect the Hubble constant to be constrained at the
precision of $\sim 10^{-2}$ with 20 well-observed binary neutron star (BNS)
mergers. Additional standard-siren measurements from other types of future
gravitational-wave sources (NS-BH and BBH) will provide more precision
constraints of this important cosmological parameter. Therefore, we obtain that
future measurements of the luminosity distances of gravitational waves sources
will be much more competitive than the current analysis, which makes it
expectable more vigorous and convincing constraints on the Hubble constant in a
cosmological-model-independent way.
