  We investigate a novel approach to measuring the Hubble constant using
gravitational-wave (GW) signals from compact binaries by exploiting the
narrowness of the distribution of masses of the underlying neutron-star
population. Gravitational-wave observations with a network of detectors will
permit a direct, independent measurement of the distance to the source systems.
If the redshift of the source is known, these inspiraling double-neutron-star
binary systems can be used as standard sirens to extract cosmological
information. Unfortunately, the redshift and the system chirp mass are
degenerate in GW observations. Thus, most previous work has assumed that the
source redshift is obtained from electromagnetic counterparts. In this paper,
we explore what we can learn about the background cosmology and the mass
distribution of neutron stars from the set of neutron-star (NS) mergers
detected by such a network. We use a Bayesian formalism to analyze catalogs of
NS-NS inspiral detections. We find that it is possible to constrain the Hubble
constant, H_0, and the parameters of the NS mass function using
gravitational-wave data alone, without relying on electromagnetic counterparts.
Under reasonable assumptions, we will be able to determine H_0 to +/- 10% using
~100 observations, provided the Gaussian half-width of the underlying double NS
mass distribution is less than 0.04 solar masses. The expected precision
depends linearly on the intrinsic width of the NS mass function, but has only a
weak dependence on H_0 near the default parameter values. Finally, we consider
what happens if, for some fraction of our data catalog, we have an
electromagnetically measured redshift. The detection, and cataloging, of these
compact-object mergers will allow precision astronomy, and provide a
determination of H_0 which is independent of the local distance scale.
